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2506 | Intergovernmental_Panel_on_Climate_Change | The IPCC confirms that computer modeling predicts the existence of a tropical, mid-troposphere "hot spot" about 10km above the Earth's surface. | Intergovernmental Panel on Climate Change The Intergovernmental Panel on Climate Change ( IPCC ) is a scientific and intergovernmental body under the auspices of the United Nations , set up at the request of member governments , dedicated to the task of providing the world with an objective , scientific view of climate change and its political and economic impacts . It was first established in 1988 by two United Nations organizations , the World Meteorological Organization ( WMO ) and the United Nations Environment Programme ( UNEP ) , and later endorsed by the United Nations General Assembly through Resolution 43/53 . Membership of the IPCC is open to all members of the WMO and UNEP . The IPCC produces reports that support the United Nations Framework Convention on Climate Change ( UNFCCC ) , which is the main international treaty on climate change . The ultimate objective of the UNFCCC is to `` stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic -LSB- i.e. , human-induced -RSB- interference with the climate system '' . IPCC reports cover `` the scientific , technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change , its potential impacts and options for adaptation and mitigation . '' The IPCC does not carry out its own original research , nor does it do the work of monitoring climate or related phenomena itself . The IPCC bases its assessment on the published literature , which includes peer-reviewed and non-peer-reviewed sources . Thousands of scientists and other experts contribute ( on a voluntary basis , without payment from the IPCC ) to writing and reviewing reports , which are then reviewed by governments . IPCC reports contain a `` Summary for Policymakers '' , which is subject to line-by-line approval by delegates from all participating governments . Typically this involves the governments of more than 120 countries . The IPCC provides an internationally accepted authority on climate change , producing reports which have the agreement of leading climate scientists and the consensus of participating governments . The 2007 Nobel Peace Prize was shared , in equal parts , between the IPCC and Al Gore . |
3104 | Atmosphere_of_Earth | the satellite sensors show less warming in the lower troposphere (approximately 10,000 feet above the earth's surface) than is reported by surface temperature readings. | Atmosphere of Earth The atmosphere of Earth is the layer of gases , commonly known as air , that surrounds the planet Earth and is retained by Earth 's gravity . The atmosphere of Earth protects life on Earth by absorbing ultraviolet solar radiation , warming the surface through heat retention ( greenhouse effect ) , and reducing temperature extremes between day and night ( the diurnal temperature variation ) . By volume , dry air contains 78.09 % nitrogen , 20.95 % oxygen , 0.93 % argon , 0.04 % carbon dioxide , and small amounts of other gases . Air also contains a variable amount of water vapor , on average around 1 % at sea level , and 0.4 % over the entire atmosphere . Air content and atmospheric pressure vary at different layers , and air suitable for use in photosynthesis by terrestrial plants and breathing of terrestrial animals is found only in Earth 's troposphere and in artificial atmospheres . The atmosphere has a mass of about 5.15 kg , three quarters of which is within about 11 km of the surface . The atmosphere becomes thinner and thinner with increasing altitude , with no definite boundary between the atmosphere and outer space . The Kármán line , at 100 km , or 1.57 % of Earth 's radius , is often used as the border between the atmosphere and outer space . Atmospheric effects become noticeable during atmospheric reentry of spacecraft at an altitude of around 120 km . Several layers can be distinguished in the atmosphere , based on characteristics such as temperature and composition . The study of Earth 's atmosphere and its processes is called atmospheric science ( aerology ) . Early pioneers in the field include Léon Teisserenc de Bort and Richard Assmann . |
467 | South_Pole | This is the South Pole ice, 90% of Earth's ice, and it's getting thicker. | South Pole The South Pole , also known as the Geographic South Pole or Terrestrial South Pole , is one of the two points where the Earth 's axis of rotation intersects its surface . It is the southernmost point on the surface of the Earth and lies on the opposite side of the Earth from the North Pole . Situated on the continent of Antarctica , it is the site of the United States Amundsen -- Scott South Pole Station , which was established in 1956 and has been permanently staffed since that year . The Geographic South Pole should not be confused with the South Magnetic Pole , which is defined based on the Earth 's magnetic field . The South Pole is at the center of the Southern Hemisphere . |
2623 | Sea_surface_temperature | (2009) have demonstrated recently – the upper troposphere (the only place where adding CO2 to the atmosphere could make any difference to temperature) is considerably drier than the models are tuned to expect." | Sea surface temperature Sea surface temperature ( SST ) is the water temperature close to the ocean 's surface . The exact meaning of surface varies according to the measurement method used , but it is between 1 mm and 20 m below the sea surface . Air masses in the Earth 's atmosphere are highly modified by sea surface temperatures within a short distance of the shore . Localized areas of heavy snow can form in bands downwind of warm water bodies within an otherwise cold air mass . Warm sea surface temperatures are known to be a cause of tropical cyclogenesis over the Earth 's oceans . Tropical cyclones can also cause a cool wake , due to turbulent mixing of the upper 30 m of the ocean . SST changes diurnally , like the air above it , but to a lesser degree . There is less SST variation on breezy days than on calm days . In addition , ocean currents such as the Atlantic Multidecadal Oscillation ( AMO ) , can effect SST 's on multi-decadal time scales , a major impact results from the global thermohaline circulation , which affects average SST significantly throughout most of the world 's oceans . Coastal SSTs can cause offshore winds to generate upwelling , which can significantly cool or warm nearby landmasses , but shallower waters over a continental shelf are often warmer . Onshore winds can cause a considerable warm-up even in areas where upwelling is fairly constant , such as the northwest coast of South America . Its values are important within numerical weather prediction as the SST influences the atmosphere above , such as in the formation of sea breezes and sea fog . It is also used to calibrate measurements from weather satellites . |
830 | Effects_of_global_warming | parts of the Earth will likely become close to uninhabitable | Effects of global warming The effects of global warming are the environmental and social changes caused ( directly or indirectly ) by human emissions of greenhouse gases . There is a scientific consensus that climate change is occurring , and that human activities are the primary driver . Many impacts of climate change have already been observed , including glacier retreat , changes in the timing of seasonal events ( e.g. , earlier flowering of plants ) , and changes in agricultural productivity . Future effects of climate change will vary depending on climate change policies and social development . The two main policies to address climate change are reducing human greenhouse gas emissions ( climate change mitigation ) and adapting to the impacts of climate change . Geoengineering is another policy option . Near-term climate change policies could significantly affect long-term climate change impacts . Stringent mitigation policies might be able to limit global warming ( in 2100 ) to around 2 ° C or below , relative to pre-industrial levels . Without mitigation , increased energy demand and extensive use of fossil fuels might lead to global warming of around 4 ° C. Higher magnitudes of global warming would be more difficult to adapt to , and would increase the risk of negative impacts . |
2256 | Greenhouse_gas | The warming effect from more CO2 greatly outstrips the influence from changes in the Earth's orbit or solar activity, even if solar levels were to drop to Maunder Minimum levels. | Greenhouse gas A greenhouse gas ( abbrev . GHG ) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range . This process is the fundamental cause of the greenhouse effect . The primary greenhouse gases in Earth 's atmosphere are water vapor , carbon dioxide , methane , nitrous oxide , and ozone . Without greenhouse gases , the average temperature of Earth 's surface would be about -18 ° C , rather than the present average of 15 ° C . In the Solar System , the atmospheres of Venus , Mars and Titan also contain gases that cause a greenhouse effect . Human activities since the beginning of the Industrial Revolution ( taken as the year 1750 ) have produced a 40 % increase in the atmospheric concentration of carbon dioxide , from 280 ppm in 1750 to 406 ppm in early 2017 . This increase has occurred despite the uptake of a large portion of the emissions by various natural `` sinks '' involved in the carbon cycle . Anthropogenic carbon dioxide emissions ( i.e. , emissions produced by human activities ) come from combustion of fossil fuels , principally coal , oil , and natural gas , along with deforestation , soil erosion and animal agriculture . It has been estimated that if greenhouse gas emissions continue at the present rate , Earth 's surface temperature could exceed historical values as early as 2047 , with potentially harmful effects on ecosystems , biodiversity and the livelihoods of people worldwide . Recent estimates suggest that on the current emissions trajectory the Earth could pass a threshold of 2 ° C global warming , which the United Nations ' IPCC designated as the upper limit to avoid `` dangerous '' global warming , by 2036 . |
2432 | Sun | The sun was warming up then, but the sun hasn't been warming since 1970. | Sun The Sun is the star at the center of the Solar System . It is a nearly perfect sphere of hot plasma , with internal convective motion that generates a magnetic field via a dynamo process . It is by far the most important source of energy for life on Earth . Its diameter is about 109 times that of Earth , and its mass is about 330,000 times that of Earth , accounting for about 99.86 % of the total mass of the Solar System . About three quarters of the Sun 's mass consists of hydrogen ( ~ 73 % ) ; the rest is mostly helium ( ~ 25 % ) , with much smaller quantities of heavier elements , including oxygen , carbon , neon , and iron . The Sun is a G-type main-sequence star ( G2V ) based on its spectral class . As such , it is informally referred to as a yellow dwarf . It formed approximately 4.6 billionAll numbers in this article are short scale . One billion is 109 , or 1,000,000,000 . years ago from the gravitational collapse of matter within a region of a large molecular cloud . Most of this matter gathered in the center , whereas the rest flattened into an orbiting disk that became the Solar System . The central mass became so hot and dense that it eventually initiated nuclear fusion in its core . It is thought that almost all stars form by this process . The Sun is roughly middle-aged ; it has not changed dramatically for more than four billion years , and will remain fairly stable for more than another five billion years . After hydrogen fusion in its core has diminished to the point at which it is no longer in hydrostatic equilibrium , the core of the Sun will experience a marked increase in density and temperature while its outer layers expand to eventually become a red giant . It is calculated that the Sun will become sufficiently large to engulf the current orbits of Mercury and Venus , and render Earth uninhabitable . The enormous effect of the Sun on Earth has been recognized since prehistoric times , and the Sun has been regarded by some cultures as a deity . The synodic rotation of Earth and its orbit around the Sun are the basis of the solar calendar , which is the predominant calendar in use today . |
97 | Global_warming | according, again, to the official figures—during this past 10 years, if anything, mean global temperature, average world temperature, has slightly declined | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
1503 | Climatology | climate models have overestimated the amount of global warming and failed to predict what climatologists call the warming 'hiatus'. | Climatology Climatology ( from Greek κλίμα , klima , `` place , zone '' ; and - λογία , - logia ) or climate science is the study of climate , scientifically defined as weather conditions averaged over a period of time . This modern field of study is regarded as a branch of the atmospheric sciences and a subfield of physical geography , which is one of the Earth sciences . Climatology now includes aspects of oceanography and biogeochemistry . Basic knowledge of climate can be used within shorter term weather forecasting using analog techniques such as the El Niño -- Southern Oscillation ( ENSO ) , the Madden -- Julian oscillation ( MJO ) , the North Atlantic oscillation ( NAO ) , the Northern Annular Mode ( NAM ) which is also known as the Arctic oscillation ( AO ) , the Northern Pacific ( NP ) Index , the Pacific decadal oscillation ( PDO ) , and the Interdecadal Pacific Oscillation ( IPO ) . Climate models are used for a variety of purposes from study of the dynamics of the weather and climate system to projections of future climate . Weather is known as the condition of the atmosphere over a period of time . While Climate has to do with the atmospheric condition over an extended to indefinite period of time . |
1466 | Greenhouse_effect | This increase is the result of humans emitting more carbon dioxide into the atmosphere and hence more being absorbed into the oceans. | Greenhouse effect The greenhouse effect is the process by which radiation from a planet 's atmosphere warms the planet 's surface to a temperature above what it would be without its atmosphere . If a planet 's atmosphere contains radiatively active gases ( i.e. , greenhouse gases ) the atmosphere will radiate energy in all directions . Part of this radiation is directed towards the surface , warming it . The downward component of this radiation -- that is , the strength of the greenhouse effect -- will depend on the atmosphere 's temperature and on the amount of greenhouse gases that the atmosphere contains . On Earth , the atmosphere is warmed by absorption of infrared thermal radiation from the underlying surface ( heated by the sun ) , absorption of shorter wavelength radiant energy from the sun , and convective heat fluxes from the surface . Greenhouse gases in the atmosphere radiate energy , some of which is directed to the surface and lower atmosphere . The mechanism that produces this difference between the actual surface temperature and the effective temperature is due to the atmosphere and is known as the greenhouse effect . Earth 's natural greenhouse effect is critical to supporting life . Human activities , primarily the burning of fossil fuels and clearing of forests , have intensified the natural greenhouse effect , causing global warming . The mechanism is named after a faulty analogy with the effect of solar radiation passing through glass and warming a greenhouse . The way a greenhouse retains heat is fundamentally different , as a greenhouse works by reducing airflow and retaining warm air inside the structure . |
1904 | United_States | If we got solar energy from "an area of the Southwestern desert 100 miles on a side, that would be enough, in and of itself, to provide 100 percent of all the electricity needs for the United States of America in a full year." | United States The United States of America ( USA ) , commonly known as the United States ( U.S. ) or America , is a constitutional federal republic composed of 50 states , a federal district , five major self-governing territories , and various possessions . Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico . The state of Alaska is in the northwest corner of North America , bordered by Canada to the east and across the Bering Strait from Russia to the west . The state of Hawaii is an archipelago in the mid-Pacific Ocean . The U.S. territories are scattered about the Pacific Ocean and the Caribbean Sea . Nine time zones are covered . The geography , climate and wildlife of the country are extremely diverse . At 3.8 million square miles ( 9.8 million km2 ) and with over 324 million people , the United States is the world 's third - or fourth-largest country by total area , third-largest by land area , and the third-most populous . It is one of the world 's most ethnically diverse and multicultural nations , and is home to the world 's largest immigrant population . The capital is Washington , D.C. , and the largest city is New York City ; nine other major metropolitan areas -- each with at least 4.5 million inhabitants and the largest having more than 13 million people -- are Los Angeles , Chicago , Dallas , Houston , Philadelphia , Miami , Atlanta , Boston , and San Francisco . Paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago . European colonization began in the 16th century . The United States emerged from 13 British colonies along the East Coast . Numerous disputes between Great Britain and the colonies following the Seven Years ' War led to the American Revolution , which began in 1775 . On July 4 , 1776 , during the course of the American Revolutionary War , the colonies unanimously adopted the Declaration of Independence . The war ended in 1783 with recognition of the independence of the United States by Great Britain , representing the first successful war of independence against a European power . The current constitution was adopted in 1788 , after the Articles of Confederation , adopted in 1781 , were felt to have provided inadequate federal powers . The first ten amendments , collectively named the Bill of Rights , were ratified in 1791 and designed to guarantee many fundamental civil liberties . The United States embarked on a vigorous expansion across North America throughout the 19th century , displacing Native American tribes , acquiring new territories , and gradually admitting new states until it spanned the continent by 1848 . During the second half of the 19th century , the American Civil War led to the end of legal slavery in the country . By the end of that century , the United States extended into the Pacific Ocean , and its economy , driven in large part by the Industrial Revolution , began to soar . The Spanish -- American War and confirmed the country 's status as a global military power . The United States emerged from as a global superpower , the first country to develop nuclear weapons , the only country to use them in warfare , and a permanent member of the United Nations Security Council . The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the world 's sole superpower . The U.S. is a founding member of the United Nations , World Bank , International Monetary Fund , Organization of American States ( OAS ) , and other international organizations . The United States is a highly developed country , with the world 's largest economy by nominal GDP and second-largest economy by PPP . Though its population is only 4.3 % of the world total , Americans hold nearly 40 % of the total wealth in the world . The United States ranks among the highest in several measures of socioeconomic performance , including average wage , human development , per capita GDP , and productivity per person . While the U.S. economy is considered post-industrial , characterized by the dominance of services and knowledge economy , the manufacturing sector remains the second-largest in the world . Accounting for approximately a quarter of global GDP and a third of global military spending , the United States is the world 's foremost economic and military power . The United States is a prominent political and cultural force internationally , and a leader in scientific research and technological innovations . |
2657 | Carbon_dioxide | Currently, humans are emitting around 29 billion tonnes of carbon dioxide into the atmosphere per year. | Carbon dioxide Carbon dioxide ( chemical formula ) is a colorless gas with a density about 60 % higher than that of air ( 1.225 g/L ) that is odorless at normally encountered concentrations . Carbon dioxide consists of a carbon atom covalently double bonded to two oxygen atoms . It occurs naturally in Earth 's atmosphere as a trace gas at a concentration of about 0.04 percent ( 400 ppm ) by volume . Natural sources include volcanoes , hot springs and geysers , and it is freed from carbonate rocks by dissolution in water and acids . Because carbon dioxide is soluble in water , it occurs naturally in groundwater , rivers and lakes , ice caps , glaciers and seawater . It is present in deposits of petroleum and natural gas . As the source of available carbon in the carbon cycle , atmospheric carbon dioxide is the primary carbon source for life on Earth and its concentration in Earth 's pre-industrial atmosphere since late in the Precambrian has been regulated by photosynthetic organisms and geological phenomena . Plants , algae and cyanobacteria use light energy to photosynthesize carbohydrate from carbon dioxide and water , with oxygen produced as a waste product . Carbon dioxide is produced by all aerobic organisms when they metabolize carbohydrates and lipids to produce energy by respiration . It is returned to water via the gills of fish and to the air via the lungs of air-breathing land animals , including humans . Carbon dioxide is produced during the processes of decay of organic materials and the fermentation of sugars in bread , beer and winemaking . It is produced by combustion of wood and other organic materials and fossil fuels such as coal , peat , petroleum and natural gas . It is a versatile industrial material , used , for example , as an inert gas in welding and fire extinguishers , as a pressurizing gas in air guns and oil recovery , as a chemical feedstock and in liquid form as a solvent in decaffeination of coffee and supercritical drying . It is added to drinking water and carbonated beverages including beer and sparkling wine to add effervescence . The frozen solid form of , known as `` dry ice '' is used as a refrigerant and as an abrasive in dry-ice blasting . Carbon dioxide is the most significant long-lived greenhouse gas in Earth 's atmosphere . Since the Industrial Revolution anthropogenic emissions - primarily from use of fossil fuels and deforestation - have rapidly increased its concentration in the atmosphere , leading to global warming . Carbon dioxide also causes ocean acidification because it dissolves in water to form carbonic acid . |
2262 | Paleoclimatology | Since the hockey stick paper in 1998, there have been a number of proxy studies analysing a variety of different sources including corals, stalagmites, tree rings, boreholes and ice cores. | Paleoclimatology Paleoclimatology ( in British spelling , palaeoclimatology ) is the study of changes in climate taken on the scale of the entire history of Earth . It uses a variety of proxy methods from the Earth and life sciences to obtain data previously preserved within things such as rocks , sediments , ice sheets , tree rings , corals , shells and microfossils . It then uses the records to determine the past states of the Earth 's various climate regions and its atmospheric system . Studies of past changes in the environment and biodiversity often reflect on the current situation , specifically the impact of climate on mass extinctions and biotic recovery . |
3102 | Fuse_(electrical) | ...there [is] anecdotal and other evidence suggesting similar melts from 1938-43 and on other occasions. | Fuse (electrical) In electronics and electrical engineering , a fuse is an electrical safety device that operates to provide overcurrent protection of an electrical circuit including the source of power and the load . Its essential component is a metal wire or strip that melts when too much current flows through it , thereby interrupting the current . It is a sacrificial device and once a fuse has operated it is an open circuit , and it must be replaced or rewired , depending on type . Fuses have been used as essential safety devices from the early days of electrical engineering , and today there are thousands of different fuse designs which have specific current and voltage ratings , breaking capacity and response times , depending on the application . The time and current operating characteristics of fuses are chosen to provide adequate protection without needless interruption . Wiring regulations usually define a maximum fuse current rating for particular circuits . Short circuits , overloading , mismatched loads , or device failure are the prime reasons for fuse operation . A fuse is an automatic means of removing power from a faulty system ; often abbreviated to ADS ( Automatic Disconnection of Supply ) . Circuit breakers can be used as an alternative design solution to fuses , but if used as direct replacements , their different characteristics must be taken into account . |
1962 | Earth | Surface temperatures on Earth "have stabilized." | Earth Earth ( from Eorðe -LSB- Γαῖα , Gaia -RSB- Terra ) , otherwise known as the World or the Globe , is the third planet from the Sun and the only object in the Universe known to harbor life . It is the densest planet in the Solar System and the largest of the four terrestrial planets . According to radiometric dating and other sources of evidence , Earth formed about 4.54 billion years ago . Earth 's gravity interacts with other objects in space , especially the Sun and the Moon , Earth 's only natural satellite . During one orbit around the Sun , Earth rotates about its axis over 365 times ; thus , an Earth year is about 365.26 days long . Earth 's axis of rotation is tilted , producing seasonal variations on the planet 's surface . The gravitational interaction between the Earth and Moon causes ocean tides , stabilizes the Earth 's orientation on its axis , and gradually slows its rotation . Earth 's lithosphere is divided into several rigid tectonic plates that migrate across the surface over periods of many millions of years . About 71 % of Earth 's surface is covered with water , mostly by its oceans . The remaining 29 % is land consisting of continents and islands that together have many lakes , rivers and other sources of water that contribute to the hydrosphere . The majority of Earth 's polar regions are covered in ice , including the Antarctic ice sheet and the sea ice of the Arctic ice pack . Earth 's interior remains active with a solid iron inner core , a liquid outer core that generates the Earth 's magnetic field , and a convecting mantle that drives plate tectonics . Within the first billion years of Earth 's history , life appeared in the oceans and began to affect the Earth 's atmosphere and surface , leading to the proliferation of aerobic and anaerobic organisms . Some geological evidence indicates that life may have arisen as much as 4.1 billion years ago . Since then , the combination of Earth 's distance from the Sun , physical properties , and geological history have allowed life to evolve and thrive . In the history of the Earth , biodiversity has gone through long periods of expansion , occasionally punctuated by mass extinction events . Over 99 % of all species that ever lived on Earth are extinct . Estimates of the number of species on Earth today vary widely ; most species have not been described . Over 7.4 billion humans live on Earth and depend on its biosphere and minerals for their survival . Humans have developed diverse societies and cultures ; politically , the world has about 200 sovereign states . |
1558 | Second_law_of_thermodynamics | 2nd law of thermodynamics contradicts greenhouse theory. | Second law of thermodynamics The second law of thermodynamics states that the total entropy of an isolated system can only increase over time . It can remain constant in ideal cases where the system is in a steady state ( equilibrium ) or undergoing a reversible process . The increase in entropy accounts for the irreversibility of natural processes , and the asymmetry between future and past . Historically , the second law was an empirical finding that was accepted as an axiom of thermodynamic theory . Statistical thermodynamics , classical or quantum , explains the microscopic origin of the law . The second law has been expressed in many ways . Its first formulation is credited to the French scientist Sadi Carnot in 1824 , who showed that there is an upper limit to the efficiency of conversion of heat to work in a heat engine . |
1473 | Retreat_of_glaciers_since_1850 | A series of just-released studies by working-level scientists prove that geological and not atmospheric forces are responsible for melting of Earth's polar ice sheets. | Retreat of glaciers since 1850 The retreat of glaciers since 1850 affects the availability of fresh water for irrigation and domestic use , mountain recreation , animals and plants that depend on glacier-melt , and , in the longer term , the level of the oceans . Studied by glaciologists , the temporal coincidence of glacier retreat with the measured increase of atmospheric greenhouse gases is often cited as an evidentiary underpinning of global warming . Mid-latitude mountain ranges such as the Himalayas , Alps , Rocky Mountains , Cascade Range , and the southern Andes , as well as isolated tropical summits such as Mount Kilimanjaro in Africa , are showing some of the largest proportionate glacial losses . Glacier mass balance is the key determinant of the health of a glacier . If the amount of frozen precipitation in the accumulation zone exceeds the quantity of glacial ice lost due to melting or in the ablation zone a glacier will advance ; if the accumulation is less than the ablation , the glacier will retreat . Glaciers in retreat will have negative mass balances , and if they do not find an equilibrium between accumulation and ablation , will eventually disappear . The Little Ice Age was a period from about 1550 to 1850 when the world experienced relatively cooler temperatures compared to the present . Subsequently , until about 1940 , glaciers around the world retreated as the climate warmed substantially . Glacial retreat slowed and even reversed temporarily , in many cases , between 1950 and 1980 as global temperatures cooled slightly . Since 1980 , a significant global warming has led to glacier retreat becoming increasingly rapid and ubiquitous , so much so that some glaciers have disappeared altogether , and the existences of many of the remaining glaciers are threatened . In locations such as the Andes of South America and Himalayas in Asia , the demise of glaciers in these regions has the potential to affect water supplies in those areas . The retreat of mountain glaciers , notably in western North America , Asia , the Alps and tropical and subtropical regions of South America , Africa and Indonesia , provide evidence for the rise in global temperatures since the late 19th century . The acceleration of the rate of retreat since 1995 of key outlet glaciers of the Greenland and West Antarctic ice sheets may foreshadow a rise in sea level , which would affect coastal regions . |
1293 | Global_warming | Over time, climate becomes a net problem: by the 2070s, the UN Climate Panel finds that global warming will likely cause damage equivalent to 0.2 per cent to 2 per cent of global GDP. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
2209 | Global_warming | Surface temperatures can show short-term cooling when heat is exchanged between the atmosphere and the ocean, which has a much greater heat capacity than the air. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
1783 | Global_warming | Internal variability can only account for small amounts of warming and cooling over periods of decades, and scientific studies have consistently shown that it cannot account for the global warming over the past century. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
390 | West_Antarctic_Ice_Sheet | there were no ice sheets covering either Greenland or West Antarctica, and much of the East Antarctic ice sheet was gone. | West Antarctic Ice Sheet The Western Antarctic Ice Sheet ( WAIS ) is the segment of the continental ice sheet that covers West ( or Lesser ) Antarctica , the portion of Antarctica on the side of the Transantarctic Mountains which lies in the Western Hemisphere . The WAIS is classified as a marine-based ice sheet , meaning that its bed lies well below sea level and its edges flow into floating ice shelves . The WAIS is bounded by the Ross Ice Shelf , the Ronne Ice Shelf , and outlet glaciers that drain into the Amundsen Sea . It is estimated that the volume of the Antarctic ice sheet is about 25.4 million km3 ( 6.1 million cu mi ) , and the WAIS contains just under 10 % of this , or 2.2 million km3 ( 530,000 cu mi ) . The weight of the ice has caused the underlying rock to sink by between 0.5 and 1 kilometres ( 0.31 -- 0.62 mi ) in a process known as isostatic depression . Under the force of its own weight , the ice sheet deforms and flows . The interior ice flows slowly over rough bedrock . In some circumstances , ice can flow faster in ice streams , separated by slow-flowing ice ridges . The inter-stream ridges are frozen to the bed while the bed beneath the ice streams consists of water-saturated sediments . Many of these sediments were deposited before the ice sheet occupied the region , when much of West Antarctica was covered by the ocean . The rapid ice-stream flow is a non-linear process still not fully understood ; streams can start and stop for unclear reasons . When ice reaches the coast , it either calves or continues to flow outward onto the water . The result is a large , floating ice shelf affixed to the continent . |
332 | Australian_residential_architectural_styles | Shelters in poorer countries are not repainted as often, and darker stations absorb more of the sun's energy. | Australian residential architectural styles Australian residential architectural styles have evolved significantly over time , from the early days of structures made from relatively cheap and imported corrugated iron ( which can still be seen in the roofing of historic homes ) to more sophisticated styles borrowed from other countries , such as the Victorian style from the United Kingdom , the Georgian style from North America and Europe and the Californian bungalow from the United States . A common feature of the Australian home is the use of fencing in front gardens , also common in both the UK and the USA . Climate has also influenced housing styles , with balconies and veranda spaces being more prevalent in subtropical Queensland due to the mild , generally warm winters experienced in the state . For many years , Australian homes were built with little understanding of the Australian climate and were widely dependant on European styles that were unsympathetic to Australian landscapes . In recent times , modern Australian residential architecture has reflected the climatic conditions of the country , with adaptations such as double and triple glazing on windows , coordination considerations , use of east and west shade , sufficient insulation , strongly considered to provide comfort to the dweller . Another aspect of Australian suburbia is that the suburbs tend to have a combination of both upper class and middle class housing in the same neighbourhood . In Melbourne , for instance , one early observer noted that `` a poor house stands side by side with a good house . '' This is somewhat less common today , with home renovations , gentrification and the teardown ( `` knock down , rebuild '' ) method becoming more and more common in affluent suburbs , giving a broader distinction between wealthy and lower class areas . However , the teardown technique has led to home buyers purchasing land or older homes in poorer metropolitan areas and building extravagant McMansion style homes on the land , which look out of place and excessive , failing to match with the remaining houses in the street . Because architectural styles have varied in the country over the years ( from villas to bungalows and brick renders ) , there is a slight inconsistency in the architectural flow of the suburban streets , with one writer noting that Australian housing styles sometimes `` co-mingle '' and `` co-exist '' awkwardly . This is less common in the United States of America and England , where most homes along a road were built around the same time , typically in similar styles . |
1376 | Scientific_consensus_on_climate_change | Also, it is increasingly clear that the planet was significantly warmer than today several times during the past 10,000 years. | Scientific consensus on climate change There is currently a strong scientific consensus that the Earth is warming and that this warming is mainly caused by human activities. This consensus is supported by various studies of scientists' opinions and by position statements of scientific organizations, many of which explicitly agree with the Intergovernmental Panel on Climate Change (IPCC) synthesis reports. Nearly all actively publishing climate scientists (97–98%) support the consensus on anthropogenic climate change, and the remaining 2% of contrarian studies either cannot be replicated or contain errors. |
1615 | Heat_wave | Climate change isn't increasing extreme weather damage costs. | Heat wave A heat wave is a prolonged period of excessively hot weather , which may be accompanied by high humidity , especially in oceanic climate countries . While definitions vary , a heat wave is measured relative to the usual weather in the area and relative to normal temperatures for the season . Temperatures that people from a hotter climate consider normal can be termed a heat wave in a cooler area if they are outside the normal climate pattern for that area . The term is applied both to hot weather variations and to extraordinary spells of hot which may occur only once a century . Severe heat waves have caused catastrophic crop failures , thousands of deaths from hyperthermia , and widespread power outages due to increased use of air conditioning . A heat wave is considered extreme weather , and a danger because heat and sunlight may overheat the human body . |
2430 | Quaternary_glaciation | Even during a period of long term warming, there are short periods of cooling due to climate variability. | Quaternary glaciation The Quaternary glaciation , also known as the Pleistocene glaciation or the current ice age , is a series of glacial events separated by interglacial events during the Quaternary period from 2.58 Ma ( million years ago ) to present . During this period , ice sheets expanded , notably from out of Antarctica and Greenland , and fluctuating ice sheets occurred elsewhere ( for example , the Laurentide ice sheet ) . The major effects of the ice age are erosion and deposition of material over large parts of the continents , modification of river systems , creation of millions of lakes , changes in sea level , development of pluvial lakes far from the ice margins , isostatic adjustment of the crust , and abnormal winds . It affected oceans , flooding , and biological communities . The ice sheets themselves , by raising the albedo , affect a major feedback on climate cooling . |
1121 | Climate_change_in_the_Arctic | Another consequence of the fast melting Arctic raises the possibility that there may be even worse extreme weather to come, according to a few scientists: titanic Atlantic superstorms and hurricanes barreling across Europe. | Climate change in the Arctic The effects of global warming in the Arctic , or climate change in the Arctic include rising temperatures , loss of sea ice , and melting of the Greenland ice sheet with a related cold temperature anomaly , observed in recent years . Potential methane release from the region , especially through the thawing of permafrost and methane clathrates , is also a concern . The Arctic warms twice as fast compared to the rest of the world . The pronounced warming signal , the amplified response of the Arctic to global warming , it is often seen as a leading indicator of global warming . The melting of Greenland 's ice sheet is linked to polar amplification . According to a study published in 2016 , about 0.5 ◦ C of the warming in the Arctic has been attributed to reductions in sulfate aerosols in Europe since 1980 . |
2122 | Sea_level | Dropped stations introduce warming bias | Sea level Mean sea level ( MSL ) ( abbreviated simply sea level ) is an average level of the surface of one or more of Earth 's oceans from which heights such as elevations may be measured . MSL is a type of vertical datuma standardised geodetic reference pointthat is used , for example , as a chart datum in cartography and marine navigation , or , in aviation , as the standard sea level at which atmospheric pressure is measured in order to calibrate altitude and , consequently , aircraft flight levels . A common and relatively straightforward mean sea-level standard is the midpoint between a mean low and mean high tide at a particular location . Sea levels can be affected by many factors and are known to have varied greatly over geological time scales . The careful measurement of variations in MSL can offer insights into ongoing climate change , and sea level rise has been widely quoted as evidence of ongoing global warming . The term above sea level generally refers to above mean sea level ( AMSL ) . |
1447 | Environmental_impact_of_aviation | Flights departing airports in the United States and its territories emitted about one-quarter (24%) of global passenger transport-related CO2, two-thirds of which came from domestic flights. | Environmental impact of aviation The environmental impact of aviation occurs because aircraft engines emit heat , noise , particulates and gases which contribute to climate change and global dimming . Among others airplanes emit particles and gases such as carbon dioxide , water vapor , hydrocarbons , carbon monoxide , nitrogen oxides , sulfur oxides , lead and black carbon which interact among themselves and with the atmosphere . Despite emission reductions from automobiles and more fuel-efficient and less polluting turbofan and turboprop engines , the rapid growth of air travel in recent years contributes to an increase in total pollution attributable to aviation . From 1992 to 2005 , passenger kilometers increased 5.2 % per year . And in the European Union , greenhouse gas emissions from aviation increased by 87 % between 1990 and 2006 . Comprehensive research shows that despite anticipated efficiency innovations to airframes , engines , aerodynamics and flight operations , there is no end in sight -- even many decades out -- to rapid growth in CO2 emissions from air travel and air freight , due to projected continual growth in air travel . This is because international aviation emissions have escaped international regulation up to the ICAO triennial conference in October 2016 agreed on the CORSIA offset scheme , and because of the lack of taxes on aviation fuel worldwide , lower fares become more frequent than otherwise which gives a competitive advantage over other transportation modes . Unless market constraints are put in place this growth in aviation 's emissions will result in the sector 's emissions amounting to all or nearly all of the annual global emissions budget by mid-century , if climate change is to be held to a temperature increase of 2 ° C or less . There is an ongoing debate about possible taxation of air travel and the inclusion of aviation in an emissions trading scheme , with a view to ensuring that the total external costs of aviation are taken into account . |
983 | Wetland | 'The dry periods are drier and the wet periods are wetter,' said Jeffrey Mount, a water expert and senior fellow at the Public Policy Institute of California. | Wetland A wetland is a land area that is saturated with water , either permanently or seasonally , such that it takes on the characteristics of a distinct ecosystem . The primary factor that distinguishes wetlands from other land forms or water bodies is the characteristic vegetation of aquatic plants , adapted to the unique hydric soil . Wetlands play a number of roles in the environment , principally water purification , flood control , carbon sink and shoreline stability . Wetlands are also considered the most biologically diverse of all ecosystems , serving as home to a wide range of plant and animal life . Wetlands occur naturally on every continent except Antarctica , the largest including the Amazon River basin , the West Siberian Plain , and the Pantanal in South America . The water found in wetlands can be freshwater , brackish , or saltwater . The main wetland types include swamps , marshes , bogs , and fens ; and sub-types include mangrove , carr , pocosin , and varzea . The UN Millennium Ecosystem Assessment determined that environmental degradation is more prominent within wetland systems than any other ecosystem on Earth . International conservation efforts are being used in conjunction with the development of rapid assessment tools to inform people about wetland issues . Constructed wetlands can be used to treat municipal and industrial wastewater as well as stormwater runoff . They may also play a role in water-sensitive urban design . |
2593 | Climate_change_feedback | [T]he study indicates "Greenland's ice may be less susceptible to the massive meltdown predicted by computer models of climate change, the main author ... said in an interview. ... | Climate change feedback Climate change feedback is important in the understanding of global warming because feedback processes may amplify or diminish the effect of each climate forcing , and so play an important part in determining the climate sensitivity and future climate state . Feedback in general is the process in which changing one quantity changes a second quantity , and the change in the second quantity in turn changes the first . Positive feedback amplifies the change in the first quantity while negative feedback reduces it . The term `` forcing '' means a change which may `` push '' the climate system in the direction of warming or cooling . An example of a climate forcing is increased atmospheric concentrations of greenhouse gases . By definition , forcings are external to the climate system while feedbacks are internal ; in essence , feedbacks represent the internal processes of the system . Some feedbacks may act in relative isolation to the rest of the climate system ; others may be tightly coupled ; hence it may be difficult to tell just how much a particular process contributes . Forcings , feedbacks and the dynamics of the climate system determine how much and how fast the climate changes . The main positive feedback in global warming is the tendency of warming to increase the amount of water vapor in the atmosphere , which in turn leads to further warming . The main negative feedback comes from the Stefan -- Boltzmann law , the amount of heat radiated from the Earth into space changes with the fourth power of the temperature of Earth 's surface and atmosphere . Some observed and potential effects of global warming are positive feedbacks , which contribute directly to further global warming . The Intergovernmental Panel on Climate Change 's ( IPCC ) Fourth Assessment Report states that `` Anthropogenic warming could lead to some effects that are abrupt or irreversible , depending upon the rate and magnitude of the climate change . '' |
586 | Mercury_(planet) | The sun was so intense, it took the mercury up to in excess of 120°F as it topped out at 122.4 °F (50.2°C). | Mercury (planet) Mercury is the smallest and innermost planet in the Solar System . Its orbital period around the Sun of 88 days is the shortest of all the planets in the Solar System . It is named after the Roman deity Mercury , the messenger to the gods . Like Venus , Mercury orbits the Sun within Earth 's orbit as an inferior planet , so it can only be seen visually in the morning or the evening sky , and never exceeds 28 ° away from the Sun . Also , like Venus and the Moon , the planet displays the complete range of phases as it moves around its orbit relative to Earth . Seen from Earth , this cycle of phases reoccurs approximately every 116 days , the so-called synodic period . Although Mercury can appear as a bright star-like object when viewed from Earth , its proximity to the Sun often makes it more difficult to see than Venus . Mercury is tidally or gravitationally locked with the Sun in a 3:2 resonance , and rotates in a way that is unique in the Solar System . As seen relative to the fixed stars , it rotates on its axis exactly three times for every two revolutions it makes around the Sun . As seen from the Sun , in a frame of reference that rotates with the orbital motion , it appears to rotate only once every two Mercurian years . An observer on Mercury would therefore see only one day every two years . Mercury 's axis has the smallest tilt of any of the Solar System 's planets ( about degree ) , and its orbital eccentricity is the largest of all known planets in the Solar System . At aphelion , Mercury is about 1.5 times as far from the Sun as it is at perihelion . Mercury 's surface appears heavily cratered and is similar in appearance to the Moon 's , indicating that it has been geologically inactive for billions of years . Having almost no atmosphere to retain heat , it has surface temperatures that vary diurnally more than on any other planet in the Solar System , ranging from 100 K at night to 700 K during the day across the equatorial regions . The polar regions are constantly below 180 K . The planet has no known natural satellites . Two spacecraft have visited Mercury : flew by in 1974 and 1975 ; and MESSENGER , launched in 2004 , orbited Mercury over 4,000 times in four years before exhausting its fuel and crashing into the planet 's surface on April 30 , 2015 . |
1555 | Humboldt_Current | Climate change is because of El Niño. | Humboldt Current The Humboldt Current System ( HCS ) , also called the Peru Current , is a major Eastern Boundary Upwelling Ecosystem that flows north along the western coast of South America . It is an eastern boundary current flowing in the direction of the equator , and extend 500-1 ,000 kilometers offshore . The Humboldt Current is named after the Prussian naturalist Alexander von Humboldt . In 1846 , von Humboldt reported measurements of the cold-water current in his book Cosmos . The current extends from the southern Chile ( ~ 45 'S ) to northern Peru ( ~ 4 'S ) where cold , upwelled waters intersect warm tropical waters to form the Equatorial Front . Sea surface temperatures off the coast of Peru , around 5 'S , reach temperatures as low as 16 ' C . This is highly uncharacteristic of tropical waters , as most other regions have temperatures measuring above 25 ' C. Upwelling brings nutrients to the surface , which support phytoplankton and ultimately increase biological productivity . Upwelling within the current is not uniform across the entire system . Three notable upwelling subsystems are produced by this current : i ) seasonal upwelling in Chile , ii ) upwelling `` shadow '' that is less productive , but still large in northern Chile and Southern Peru , and iii ) year-round upwelling in Peru . The Humboldt Current is considered a Class I , highly productive ( > 300 gC/m2-yr ) , ecosystem . It is the most productive eastern boundary current system . It accounts for roughly 18-20 % of the total worldwide marine fish catch . The species are mostly pelagic : sardines , anchovies and jack mackerel . The system 's high productivity supports other important fishery resources as well as marine mammals ( eared seals and cetaceans ) and seabirds . The cold , nutrient-rich water brought to the surface by upwelling drives the system 's extraordinary productivity.Periodically , the upwelling that drives the system 's productivity is disrupted by the El Niño-Southern Oscillation ( ENSO ) event . When this occurs , fish abundance and distribution are significantly affected , often leading to stock crashes and cascading social and economic impacts . These events have led to sequential changes , where sardines and anchovies have replaced each other periodically as the dominant species in the ecosystem . These species changes can have negative consequences for the fishing industry and the economies of the countries that fish the system . The Humboldt has a considerable cooling influence on the climate of Chile , Peru and Ecuador . It is also largely responsible for the aridity of Atacama Desert in northern Chile and coastal areas of Peru and also of the aridity of southern Ecuador . Marine air is cooled by the current and thus is not conducive to generating precipitation ( although clouds and fog are produced ) . |
1431 | Global_warming | Eleven percent of all global greenhouse gas emissions caused by humans are caused by deforestation — comparable to the emissions from all of the cars and trucks on the planet. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
2549 | Intergovernmental_Panel_on_Climate_Change | "Many people think the science of climate change is settled. | Intergovernmental Panel on Climate Change The Intergovernmental Panel on Climate Change ( IPCC ) is a scientific and intergovernmental body under the auspices of the United Nations , set up at the request of member governments , dedicated to the task of providing the world with an objective , scientific view of climate change and its political and economic impacts . It was first established in 1988 by two United Nations organizations , the World Meteorological Organization ( WMO ) and the United Nations Environment Programme ( UNEP ) , and later endorsed by the United Nations General Assembly through Resolution 43/53 . Membership of the IPCC is open to all members of the WMO and UNEP . The IPCC produces reports that support the United Nations Framework Convention on Climate Change ( UNFCCC ) , which is the main international treaty on climate change . The ultimate objective of the UNFCCC is to `` stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic -LSB- i.e. , human-induced -RSB- interference with the climate system '' . IPCC reports cover `` the scientific , technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change , its potential impacts and options for adaptation and mitigation . '' The IPCC does not carry out its own original research , nor does it do the work of monitoring climate or related phenomena itself . The IPCC bases its assessment on the published literature , which includes peer-reviewed and non-peer-reviewed sources . Thousands of scientists and other experts contribute ( on a voluntary basis , without payment from the IPCC ) to writing and reviewing reports , which are then reviewed by governments . IPCC reports contain a `` Summary for Policymakers '' , which is subject to line-by-line approval by delegates from all participating governments . Typically this involves the governments of more than 120 countries . The IPCC provides an internationally accepted authority on climate change , producing reports which have the agreement of leading climate scientists and the consensus of participating governments . The 2007 Nobel Peace Prize was shared , in equal parts , between the IPCC and Al Gore . |
2282 | Subantarctic | While there are isolated cases of growing glaciers, the overwhelming trend in glaciers worldwide is retreat. | Subantarctic The Subantarctic is a region in the southern hemisphere , located immediately north of the Antarctic region . This translates roughly to a latitude of between 46 ° -- 60 ° south of the Equator . The subantarctic region includes many islands in the southern parts of the Indian Ocean , Atlantic Ocean and Pacific Ocean , especially those situated north of the Antarctic Convergence . Subantarctic glaciers are , by definition , located on islands within the subantarctic region . All glaciers located on the continent of Antarctica are by definition considered to be Antarctic glaciers . |
1227 | River_Parrett | These tidal floods are often just a foot or two deep, but they can stop traffic, swamp basements, damage cars, kill lawns and forests, and poison wells with salt. | River Parrett The River Parrett flows through the counties of Dorset and Somerset in South West England , from its source in the Thorney Mills springs in the hills around Chedington in Dorset . Flowing northwest through Somerset and the Somerset Levels to its mouth at Burnham-on-Sea , into the Bridgwater Bay nature reserve on the Bristol Channel , the Parrett and its tributaries drain an area of 1700 km2 -- about 50 per cent of Somerset 's land area , with a population of 300,000 . The Parrett 's main tributaries include the Rivers Tone , Isle , and Yeo , and the River Cary via the King 's Sedgemoor Drain . The 37 mi long river is tidal for 19 mi up to Oath . The fall of the river between Langport and Bridgwater is only 1 ft/mi , so it is prone to frequent flooding in winter and during high tides . Many approaches have been tried since at least the medieval period to reduce the incidence and effect of floods and to drain the surrounding fields . In Anglo-Saxon times the river formed a boundary between Wessex and Dumnonia . It later served the Port of Bridgwater , and enabled cargoes to be transported inland . The arrival of the railways led to a decline in commercial shipping , and the only working docks are at Dunball . Man 's influence on the river has left a legacy of bridges and industrial artefacts . The Parrett along with its connected waterways and network of drains supports an ecosystem that includes several rare species of flora and fauna . The River Parrett Trail has been established along the banks of the river . |
302 | Climate_change_mitigation | In addition, [climate models] ignore the fact that enriching the atmosphere with CO2 is beneficial | Climate change mitigation Climate change mitigation consists of actions to limit the magnitude or rate of long-term climate change . Climate change mitigation generally involves reductions in human ( anthropogenic ) emissions of greenhouse gases ( GHGs ) . Mitigation may also be achieved by increasing the capacity of carbon sinks , e.g. , through reforestation . Mitigation policies can substantially reduce the risks associated with human-induced global warming . According to the IPCC 's 2014 assessment report , `` Mitigation is a public good ; climate change is a case of the ` tragedy of the commons . Effective climate change mitigation will not be achieved if each agent ( individual , institution or country ) acts independently in its own selfish interest ( see international cooperation and emissions trading ) , suggesting the need for collective action . Some adaptation actions , on the other hand , have characteristics of a private good as benefits of actions may accrue more directly to the individuals , regions , or countries that undertake them , at least in the short term . Nevertheless , financing such adaptive activities remains an issue , particularly for poor individuals and countries . '' Examples of mitigation include phasing out fossil fuels by switching to low-carbon energy sources , such as renewable and nuclear energy , and expanding forests and other `` sinks '' to remove greater amounts of carbon dioxide from the atmosphere . Energy efficiency may also play a role , for example , through improving the insulation of buildings . Another approach to climate change mitigation is climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) . The ultimate objective of the UNFCCC is to stabilize atmospheric concentrations of GHGs at a level that would prevent dangerous human interference of the climate system . Scientific analysis can provide information on the impacts of climate change , but deciding which impacts are dangerous requires value judgments . In 2010 , Parties to the UNFCCC agreed that future global warming should be limited to below 2.0 ° C ( 3.6 ° F ) relative to the pre-industrial level . With the Paris Agreement of 2015 this was confirmed , but was revised with a new target laying down `` parties will do the best '' to achieve warming below 1.5 ° C . The current trajectory of global greenhouse gas emissions does not appear to be consistent with limiting global warming to below 1.5 or 2 ° C . Other mitigation policies have been proposed , some of which are more stringent or modest than the 2 ° C limit . |
864 | Carbon_dioxide | "[Carbon dioxide] just crossed 400 parts per million, and high-end estimates extrapolating from current trends suggest it will hit 1,000 ppm by 2100. | Carbon dioxide Carbon dioxide ( chemical formula ) is a colorless gas with a density about 60 % higher than that of air ( 1.225 g/L ) that is odorless at normally encountered concentrations . Carbon dioxide consists of a carbon atom covalently double bonded to two oxygen atoms . It occurs naturally in Earth 's atmosphere as a trace gas at a concentration of about 0.04 percent ( 400 ppm ) by volume . Natural sources include volcanoes , hot springs and geysers , and it is freed from carbonate rocks by dissolution in water and acids . Because carbon dioxide is soluble in water , it occurs naturally in groundwater , rivers and lakes , ice caps , glaciers and seawater . It is present in deposits of petroleum and natural gas . As the source of available carbon in the carbon cycle , atmospheric carbon dioxide is the primary carbon source for life on Earth and its concentration in Earth 's pre-industrial atmosphere since late in the Precambrian has been regulated by photosynthetic organisms and geological phenomena . Plants , algae and cyanobacteria use light energy to photosynthesize carbohydrate from carbon dioxide and water , with oxygen produced as a waste product . Carbon dioxide is produced by all aerobic organisms when they metabolize carbohydrates and lipids to produce energy by respiration . It is returned to water via the gills of fish and to the air via the lungs of air-breathing land animals , including humans . Carbon dioxide is produced during the processes of decay of organic materials and the fermentation of sugars in bread , beer and winemaking . It is produced by combustion of wood and other organic materials and fossil fuels such as coal , peat , petroleum and natural gas . It is a versatile industrial material , used , for example , as an inert gas in welding and fire extinguishers , as a pressurizing gas in air guns and oil recovery , as a chemical feedstock and in liquid form as a solvent in decaffeination of coffee and supercritical drying . It is added to drinking water and carbonated beverages including beer and sparkling wine to add effervescence . The frozen solid form of , known as `` dry ice '' is used as a refrigerant and as an abrasive in dry-ice blasting . Carbon dioxide is the most significant long-lived greenhouse gas in Earth 's atmosphere . Since the Industrial Revolution anthropogenic emissions - primarily from use of fossil fuels and deforestation - have rapidly increased its concentration in the atmosphere , leading to global warming . Carbon dioxide also causes ocean acidification because it dissolves in water to form carbonic acid . |
2896 | GRACE_and_GRACE-FO | But gravity measurements of ice-mass loss are complicated by glacial isostatic adjustments—compensation for the rise or fall of the underlying crustal material. | GRACE and GRACE-FO The Gravity Recovery and Climate Experiment (GRACE) was a joint mission of NASA and the German Aerospace Center (DLR). Twin satellites took detailed measurements of Earth's gravity field anomalies from its launch in March 2002 to the end of its science mission in October 2017. The Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) is a continuation of the mission on near-identical hardware, launched in May 2018. By measuring gravity anomalies, GRACE showed how mass is distributed around the planet and how it varies over time. Data from the GRACE satellites is an important tool for studying Earth's ocean, geology, and climate. GRACE was a collaborative endeavor involving the Center for Space Research at the University of Texas at Austin, NASA's Jet Propulsion Laboratory, the German Aerospace Center and Germany's National Research Center for Geosciences, Potsdam. The Jet Propulsion Laboratory was responsible for the overall mission management under the NASA ESSP (Earth System Science Pathfinder) program. The principal investigator is Byron Tapley of the University of Texas Center for Space Research, and the co-principal investigator is Christoph Reigber of the GeoForschungsZentrum (GFZ) Potsdam.The two GRACE satellites (GRACE-1 and GRACE-2) were launched from Plesetsk Cosmodrome, Russia, on a Rockot (SS-19 + Breeze upper stage) launch vehicle on 17 March 2002. The spacecraft were launched to an initial altitude of approximately 500 km at a near-polar inclination of 89°. During normal operations, the satellites were separated by 220 km along their orbit track. This system was able to gather global coverage every 30 days. GRACE far exceeded its 5-year design lifespan, operating for 15 years until the decommissioning of GRACE-2 on 27 October 2017. Its successor, GRACE-FO, was successfully launched on 22 May 2018. In 2019, a glacier in West Antarctica was named after the GRACE mission. |
2325 | Climate_of_Mars | Martian climate is primarily driven by dust and albedo and there is little empirical evidence that Mars is showing long term warming. | Climate of Mars The climate of Mars has been an issue of scientific curiosity for centuries , in part because Mars is the only terrestrial planet whose surface can be directly observed in detail from the Earth with help from a telescope . Although Mars is smaller than the Earth , at 11 % of Earth 's mass , and 50 % farther from the Sun than the Earth , its climate has important similarities , such as the polar ice caps , seasonal changes and the observable presence of weather patterns . It has attracted sustained study from planetologists and climatologists . While Mars 's climate has similarities to Earth 's , including periodic ice ages , there are also important differences , such as much lower thermal inertia . Mars ' atmosphere has a scale height of approximately 11 km , 60 % greater than that on Earth . The climate is of considerable relevance to the question of whether life is or was present on the planet . The climate briefly received more interest in the news due to NASA measurements indicating increased sublimation of the south polar icecap leading to some popular press speculation that Mars was undergoing a parallel bout of global warming , although Mars ' average temperature has actually cooled in recent decades . Mars has been studied by Earth-based instruments since the 17th century but it is only since the exploration of Mars began in the mid-1960s that close-range observation has been possible . Flyby and orbital spacecraft have provided data from above , while direct measurements of atmospheric conditions have been provided by a number of landers and rovers . Advanced Earth orbital instruments today continue to provide some useful `` big picture '' observations of relatively large weather phenomena . The first Martian flyby mission was Mariner 4 which arrived in 1965 . That quick two-day pass ( July 14 -- 15 , 1965 ) was limited and crude in terms of its contribution to the state of knowledge of Martian climate . Later Mariner missions ( Mariner 6 , and Mariner 7 ) filled in some of the gaps in basic climate information . Data-based climate studies started in earnest with the Viking program in 1975 and continues with such probes as the Mars Reconnaissance Orbiter . This observational work has been complemented by a type of scientific computer simulation called the Mars general circulation model . Several different iterations of MGCM have led to an increased understanding of Mars as well as the limits of such models . |
358 | Environmental_sociology | Their analysis calculates the existential climate-related security risk to Earth through a scenario set 30 years into the future. | Environmental sociology Environmental sociology is typically defined as the sociological study of societal-environmental interactions , although this definition immediately presents the problem of integrating human cultures with the rest of the environment . Although the focus of the field is the relationship between society and environment in general , environmental sociologists typically place special emphasis on studying the social factors that cause environmental problems , the societal impacts of those problems , and efforts to solve the problems . In addition , considerable attention is paid to the social processes by which certain environmental conditions become socially defined as problems . Although there was sometimes acrimonious debate between the constructivist and realist `` camps '' within environmental sociology in the 1990s , the two sides have found considerable common ground as both increasingly accept that while most environmental problems have a material reality they nonetheless become known only via human processes such as scientific knowledge , activists ' efforts , and media attention . In other words , most environmental problems have a real ontological status despite our knowledge/awareness of them stemming from social processes , processes by which various conditions are constructed as problems by scientists , activists , media and other social actors . Correspondingly , environmental problems must all be understood via social processes , despite any material basis they may have external to humans . This interactiveness is now broadly accepted , but many aspects of the debate continue in contemporary research in the field . |
2189 | Scientific_consensus_on_climate_change | This makes it clear that this time around humans are the cause, mainly by our CO2 emissions. | Scientific consensus on climate change There is currently a strong scientific consensus that the Earth is warming and that this warming is mainly caused by human activities. This consensus is supported by various studies of scientists' opinions and by position statements of scientific organizations, many of which explicitly agree with the Intergovernmental Panel on Climate Change (IPCC) synthesis reports. Nearly all actively publishing climate scientists (97–98%) support the consensus on anthropogenic climate change, and the remaining 2% of contrarian studies either cannot be replicated or contain errors. |
1090 | Phalodi | Extreme high temperatures were seen from India — where the city of Phalodi recorded temperatures of 51 degrees Celsius (123.8 Fahrenheit) in May, a new national record — to Iran, where a temperature of 53 degrees Celsius (127.4 F) was recorded in Delhoran on July 22. | Phalodi Phalodi is a city and a municipality in Jodhpur district in the Indian state of Rajasthan . It is the headquarters for Phalodi tehsil . Phalodi is also called the `` salt city '' due to the concentration of a large number of salt industries located in the area . Phalodi is in the buffer zone of Thar Desert and often subject to extreme temperature conditions due to arid climate . It holds the record for the highest verified temperature recorded in India at 52 degrees Celsius ( 123.8 ° F ) on 20 May 2016 . |
2746 | WSEE-TV | Dropped weather stations actually show a slightly warmer trend compared to kept stations. | WSEE-TV WSEE-TV is the CBS-affiliated television station for Northwestern Pennsylvania that is licensed to Erie . It broadcasts a high definition digital signal on UHF channel 16 ( or virtual channel 35.1 via PSIP ) from a transmitter on Old Waterford Road in Greene Township . The station can also be seen on Spectrum channel 5 and in high definition on digital channel 1005 . Owned by Lilly Broadcasting , WSEE-TV operates the area 's NBC affiliate WICU-TV ( owned by SJL Broadcasting ) through a shared services agreement ( SSA ) and the two outlets share studios on State Street in Erie . Until 2017 , WSEE was also seen over-the-air in standard definition on WICU-TV 's third digital subchannel on VHF channel 12.3 from the same Greene Township transmitter . |
757 | Wetland | The grasslands, crops, forests and territorial waters of Australia absorb more carbon dioxide than Australia emits. | Wetland A wetland is a land area that is saturated with water , either permanently or seasonally , such that it takes on the characteristics of a distinct ecosystem . The primary factor that distinguishes wetlands from other land forms or water bodies is the characteristic vegetation of aquatic plants , adapted to the unique hydric soil . Wetlands play a number of roles in the environment , principally water purification , flood control , carbon sink and shoreline stability . Wetlands are also considered the most biologically diverse of all ecosystems , serving as home to a wide range of plant and animal life . Wetlands occur naturally on every continent except Antarctica , the largest including the Amazon River basin , the West Siberian Plain , and the Pantanal in South America . The water found in wetlands can be freshwater , brackish , or saltwater . The main wetland types include swamps , marshes , bogs , and fens ; and sub-types include mangrove , carr , pocosin , and varzea . The UN Millennium Ecosystem Assessment determined that environmental degradation is more prominent within wetland systems than any other ecosystem on Earth . International conservation efforts are being used in conjunction with the development of rapid assessment tools to inform people about wetland issues . Constructed wetlands can be used to treat municipal and industrial wastewater as well as stormwater runoff . They may also play a role in water-sensitive urban design . |
2726 | Greenhouse_gas | Humans are emitting 26 gigatonnes of CO2 into the atmosphere. | Greenhouse gas A greenhouse gas ( abbrev . GHG ) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range . This process is the fundamental cause of the greenhouse effect . The primary greenhouse gases in Earth 's atmosphere are water vapor , carbon dioxide , methane , nitrous oxide , and ozone . Without greenhouse gases , the average temperature of Earth 's surface would be about -18 ° C , rather than the present average of 15 ° C . In the Solar System , the atmospheres of Venus , Mars and Titan also contain gases that cause a greenhouse effect . Human activities since the beginning of the Industrial Revolution ( taken as the year 1750 ) have produced a 40 % increase in the atmospheric concentration of carbon dioxide , from 280 ppm in 1750 to 406 ppm in early 2017 . This increase has occurred despite the uptake of a large portion of the emissions by various natural `` sinks '' involved in the carbon cycle . Anthropogenic carbon dioxide emissions ( i.e. , emissions produced by human activities ) come from combustion of fossil fuels , principally coal , oil , and natural gas , along with deforestation , soil erosion and animal agriculture . It has been estimated that if greenhouse gas emissions continue at the present rate , Earth 's surface temperature could exceed historical values as early as 2047 , with potentially harmful effects on ecosystems , biodiversity and the livelihoods of people worldwide . Recent estimates suggest that on the current emissions trajectory the Earth could pass a threshold of 2 ° C global warming , which the United Nations ' IPCC designated as the upper limit to avoid `` dangerous '' global warming , by 2036 . |
2004 | Barack_Obama | They (Clinton and Obama) have never to my knowledge been involved in legislation nor hearings nor engagement on this issue (climate change). | Barack Obama Barack Hussein Obama II ( -LSB- bəˈrɑːk_huːˈseɪn_oʊˈbɑːmə -RSB- ; born August 4 , 1961 ) is an American politician who served as the 44th President of the United States from 2009 to 2017 . He is the first African American to have served as president . He previously served in the U.S. Senate representing Illinois from 2005 to 2008 , and in the Illinois State Senate from 1997 to 2004 . Obama was born in Honolulu , Hawaii , two years after the territory was admitted to the Union as the 50th state . Raised largely in Hawaii , Obama also spent one year of his childhood in Washington State and four years in Indonesia . After graduating from Columbia University in 1983 , he worked as a community organizer in Chicago . In 1988 Obama enrolled in Harvard Law School , where he was the first black president of the Harvard Law Review . After graduation , he became a civil rights attorney and professor , teaching constitutional law at the University of Chicago Law School from 1992 to 2004 . Obama represented the 13th District for three terms in the Illinois Senate from 1997 to 2004 , when he ran for the U.S. Senate . Obama received national attention in 2004 , with his unexpected March primary win , his well-received July Democratic National Convention keynote address , and his landslide November election to the Senate . In 2008 , Obama was nominated for president , a year after his campaign began , and after a close primary campaign against Hillary Clinton . He was elected over Republican John McCain , and was inaugurated on January 20 , 2009 . Nine months later , Obama was named the 2009 Nobel Peace Prize laureate . During his first two years in office , Obama signed many landmark bills . Main reforms were the Patient Protection and Affordable Care Act ( often referred to as `` Obamacare '' ) , the Dodd -- Frank Wall Street Reform and Consumer Protection Act , and the Do n't Ask , Do n't Tell Repeal Act of 2010 . The American Recovery and Reinvestment Act of 2009 and Tax Relief , Unemployment Insurance Reauthorization , and Job Creation Act of 2010 served as economic stimulus amidst the Great Recession , but the GOP regained control of the House of Representatives in 2011 . After a lengthy debate over the national debt limit , Obama signed the Budget Control and the American Taxpayer Relief Acts . In foreign policy , Obama increased U.S. troop levels in Afghanistan , reduced nuclear weapons with the U.S.-Russian New START treaty , and ended military involvement in the Iraq War . He ordered military involvement in Libya in opposition to Muammar Gaddafi , and the military operation that resulted in the death of Osama bin Laden . After winning re-election by defeating Republican nominee Mitt Romney , Obama was sworn in for a second term in 2013 . During his second term , Obama promoted greater inclusiveness for LGBT Americans , with his administration filing briefs that urged the Supreme Court to strike down same-sex marriage bans as unconstitutional ( United States v. Windsor and Obergefell v. Hodges ) . Obama also advocated gun control in response to the Sandy Hook Elementary School shooting , and issued wide-ranging executive actions concerning climate change and immigration . In foreign policy , Obama ordered military intervention in Iraq in response to gains made by ISIL after the 2011 withdrawal from Iraq , continued the process of ending U.S. combat operations in Afghanistan , promoted discussions that led to the 2015 Paris Agreement on global climate change , initiated the sanctions against Russia following the invasion in Ukraine , brokered a nuclear deal with Iran , and normalized U.S. relations with Cuba . Obama left office in January 2017 with a 60 % approval rating . He currently resides in Washington , D.C. His presidential library will be built in Chicago . |
905 | Carbon_dioxide_in_Earth's_atmosphere | "Some experts, such as UN climate scientist Dr. Indur Goklany, have defended rising CO2 levels as a good thing for humanity. | Carbon dioxide in Earth's atmosphere Carbon dioxide is an important trace gas in Earth 's atmosphere . Currently it constitutes about 0.041 % ( equal to 410 parts per million ; ppm ) by volume of the atmosphere . Despite its relatively small concentration is a potent greenhouse gas and plays a vital role in regulating Earth 's surface temperature through radiative forcing and the greenhouse effect . Reconstructions show that concentrations of in the atmosphere have varied , ranging from as high as 7,000 ppm during the Cambrian period about 500 million years ago to as low as 180 ppm during the Quaternary glaciation of the last two million years . Carbon dioxide is an integral part of the carbon cycle , a biogeochemical cycle in which carbon is exchanged between the Earth 's oceans , soil , rocks and the biosphere . Plants and other photoautotrophs use solar energy to produce carbohydrate from atmospheric carbon dioxide and water by photosynthesis . Almost all other organisms depend on carbohydrate derived from photosynthesis as their primary source of energy and carbon compounds . The current episode of global warming is attributed to increasing emissions of and other greenhouse gases into Earth 's atmosphere . The global annual mean concentration of in the atmosphere has increased by more than 40 % since the start of the Industrial Revolution , from 280 ppm , the level it had for the last 10,000 years leading up to the mid-18th century , to 399 ppm as of 2015 . The present concentration is the highest in at least the past 800,000 years and likely the highest in the past 20 million years . The increase has been caused by anthropogenic sources , particularly the burning of fossil fuels and deforestation . The daily average concentration of atmospheric CO2 at Mauna Loa Observatory first exceeded 400 ppm on 10 May 2013 . It is currently rising at a rate of approximately 2 ppm/year and accelerating . An estimated 30 -- 40 % of the released by humans into the atmosphere dissolves into oceans , rivers and lakes , which contributes to ocean acidification . |
761 | Effects_of_global_warming_on_human_health | [Riebesell] is a world authority on the topic and has typically communicated cautiously about the effects of acidification. | Effects of global warming on human health The effects of global warming include effects on human health . The observed and projected increased frequency and severity of climate related impacts will further exacerbate the effects on human health . This article describes some of those effects on individuals and populations . |
1998 | 2013_New_South_Wales_bushfires | There is a link between climate change and the NSW bushfires. | 2013 New South Wales bushfires The 2013 New South Wales bushfires were a series of bushfires in Australia across the state of New South Wales primarily starting , or becoming notable , on 13 October 2013 ; followed by the worst of the fires beginning in the Greater Blue Mountains Area on 16 and 17 October 2013 . High fuel loads , coupled with warm , dry and windy weather , provided dangerous conditions which fuelled the fires . At the peak of the fires , on the morning of 18 October , over 100 fires were burning across the state . The Premier of New South Wales Barry O'Farrell declared a state of emergency on 20 October , empowering firefighters to evict residents and demolish fire-affected buildings . The fires are the worst in New South Wales since the 1960s . , 248 houses and other structures were destroyed across the state . Two fatalities were attributed to the fires . It was estimated that claims will exceed 94 million . |
181 | Anthozoa | Reefs need carbon dioxide; it's their basic food. | Anthozoa Anthozoa is a class within the phylum Cnidaria . Unlike other cnidarians , anthozoans do not have a medusa stage in their development . Instead , they release sperm and eggs that form a planula , which attaches to some substrate on which the cnidarian grows . Some anthozoans can also reproduce asexually through budding . More than 6,100 species have been described . The name comes from the Greek words -LSB- : wikt : άνθος , άνθος -RSB- ( ánthos ; `` flower '' ) and -LSB- : wikt : ζῷον , ζώα -RSB- ( zóa ; `` animals '' ) , hence ανθόζωα ( anthozoa ) = `` flower animals '' , a reference to the floral appearance of their perennial polyp stage . |
1108 | Scientific_journal | There was, he said, an 'inherent bias' in scientific journals which predisposed them to publish 'doom and gloom stories'. | Scientific journal In academic publishing , a scientific journal is a periodical publication intended to further the progress of science , usually by reporting new research . There are thousands of scientific journals in publication , and many more have been published at various points in the past ( see list of scientific journals ) . Most journals are highly specialized , although some of the oldest journals such as Nature publish articles and scientific papers across a wide range of scientific fields . Scientific journals contain articles that have been peer reviewed , in an attempt to ensure that articles meet the journal 's standards of quality , and scientific validity . If the journal 's editor considers the paper appropriate , at least two researchers preferably from the same field check the paper for soundness of its scientific argument , and must agree to publish it . Although scientific journals are superficially similar to professional magazines , they are actually quite different . Issues of a scientific journal are rarely read casually , as one would read a magazine . The publication of the results of research is an essential part of the scientific method . If they are describing experiments or calculations , they must supply enough details that an independent researcher could repeat the experiment or calculation to verify the results . Each such journal article becomes part of the permanent scientific record . The history of scientific journals dates from 1665 , when the French Journal des sçavans and the English Philosophical Transactions of the Royal Society first began systematically publishing research results . Over a thousand , mostly ephemeral , were founded in the 18th century , and the number has increased rapidly after that . Articles in scientific journals can be used in research and higher education . Scientific articles allow researchers to keep up to date with the developments of their field and direct their own research . An essential part of a scientific article is citation of earlier work . The impact of articles and journals is often assessed by counting citations ( citation impact ) . Some classes are partially devoted to the explication of classic articles , and seminar classes can consist of the presentation by each student of a classic or current paper . Schoolbooks and textbooks have been written usually only on established topics , while the latest research and more obscure topics are only accessible through scientific articles . In a scientific research group or academic department it is usual for the content of current scientific journals to be discussed in journal clubs . Academic credentials for promotion into academic ranks are established in large part by the number and impact of scientific articles published , and many doctoral programs allow for thesis by publication , where the candidate is required to publish a certain number of scientific articles . The standards that a journal uses to determine publication can vary widely . Some journals , such as Nature , Science , PNAS , and Physical Review Letters , have a reputation of publishing articles that mark a fundamental breakthrough in their respective fields . In many fields , a formal or informal hierarchy of scientific journals exists ; the most prestigious journal in a field tends to be the most selective in terms of the articles it will select for publication , and usually will also have the highest impact factor . In some countries , journal rankings can be utilized for funding decisions and even evaluation of individual researchers , although they are poorly suited for that purpose . It is also common for journals to have a regional focus , specializing in publishing papers from a particular country or other geographic region , like African Invertebrates . Articles tend to be highly technical , representing the latest theoretical research and experimental results in the field of science covered by the journal . They are often incomprehensible to anyone except for researchers in the field and advanced students . In some subjects this is inevitable given the nature of the content . Usually , rigorous rules of scientific writing are enforced by the editors ; however , these rules may vary from journal to journal , especially between journals from different publishers . Articles are usually either original articles reporting completely new results or reviews of current literature . There are also scientific publications that bridge the gap between articles and books by publishing thematic volumes of chapters from different authors . |
2335 | Satellite_temperature_measurements | Satellite measurements of infrared spectra over the past 40 years observe less energy escaping to space at the wavelengths associated with CO2. | Satellite temperature measurements The temperature of the atmosphere at various altitudes as well as sea and land surface temperatures can be inferred from satellite measurements . These measurements can be used to locate weather fronts , monitor the El Niño-Southern Oscillation , determine the strength of tropical cyclones , study urban heat islands and monitor the global climate . Wildfires , volcanos , and industrial hot spots can also be found via thermal imaging from weather satellites . Weather satellites do not measure temperature directly . They measure radiances in various wavelength bands . Since 1978 microwave sounding units ( MSUs ) on National Oceanic and Atmospheric Administration polar orbiting satellites have measured the intensity of upwelling microwave radiation from atmospheric oxygen , which is related to the temperature of broad vertical layers of the atmosphere . Measurements of infrared radiation pertaining to sea surface temperature have been collected since 1967 . Satellite datasets show that over the past four decades the troposphere has warmed and the stratosphere has cooled . Both of these trends are consistent with the influence of increasing atmospheric concentrations of greenhouse gases . |
2981 | Water | Thus rather than a "doomsday" cycle of runaway warming, Mother Earth appears surprisingly tolerant of carbon, decreasing atmospheric levels of water vapor -- a more effective greenhouse gas -- to compensate. | Water Water is a transparent and nearly colorless chemical substance that is the main constituent of Earth 's streams , lakes , and oceans , and the fluids of most living organisms . Its chemical formula is H2O , meaning that its molecule contains one oxygen and two hydrogen atoms , that are connected by covalent bonds . Water strictly refers to the liquid state of that substance , that prevails at standard ambient temperature and pressure ; but it often refers also to its solid state ( ice ) or its gaseous state ( steam or water vapor ) . It also occurs in nature as snow , glaciers , ice packs and icebergs , clouds , fog , dew , aquifers , and atmospheric humidity . Water covers 71 % of the Earth 's surface . It is vital for all known forms of life . On Earth , 96.5 % of the planet 's crust water is found in seas and oceans , 1.7 % in groundwater , 1.7 % in glaciers and the ice caps of Antarctica and Greenland , a small fraction in other large water bodies , and 0.001 % in the air as vapor , clouds ( formed of ice and liquid water suspended in air ) , and precipitation . Only 2.5 % of this water is freshwater , and 98.8 % of that water is in ice ( excepting ice in clouds ) and groundwater . Less than 0.3 % of all freshwater is in rivers , lakes , and the atmosphere , and an even smaller amount of the Earth 's freshwater ( 0.003 % ) is contained within biological bodies and manufactured products . A greater quantity of water is found in the earth 's interior . Water on Earth moves continually through the water cycle of evaporation and transpiration ( evapotranspiration ) , condensation , precipitation , and runoff , usually reaching the sea . Evaporation and transpiration contribute to the precipitation over land . Large amounts of water are also chemically combined or adsorbed in hydrated minerals . Safe drinking water is essential to humans and other lifeforms even though it provides no calories or organic nutrients . Access to safe drinking water has improved over the last decades in almost every part of the world , but approximately one billion people still lack access to safe water and over 2.5 billion lack access to adequate sanitation . There is a clear correlation between access to safe water and gross domestic product per capita . However , some observers have estimated that by 2025 more than half of the world population will be facing water-based vulnerability . A report , issued in November 2009 , suggests that by 2030 , in some developing regions of the world , water demand will exceed supply by 50 % . Water plays an important role in the world economy . Approximately 70 % of the freshwater used by humans goes to agriculture . Fishing in salt and fresh water bodies is a major source of food for many parts of the world . Much of long-distance trade of commodities ( such as oil and natural gas ) and manufactured products is transported by boats through seas , rivers , lakes , and canals . Large quantities of water , ice , and steam are used for cooling and heating , in industry and homes . Water is an excellent solvent for a wide variety of chemical substances ; as such it is widely used in industrial processes , and in cooking and washing . Water is also central to many sports and other forms of entertainment , such as swimming , pleasure boating , boat racing , surfing , sport fishing , and diving . |
862 | Mesoamerican_nephropathy | In the sugarcane region of El Salvador, as much as one-fifth of the population has chronic kidney disease, including over a quarter of the men, the presumed result of dehydration from working the fields they were able to comfortably harvest as recently as two decades ago. | Mesoamerican nephropathy Mesoamerican nephropathy ( MeN ) is a currently unexplained epidemic of chronic kidney disease of unknown origin ( CKDu ) , prevalent in the Pacific ocean coastal low lands of the mesoamerican region , including southern Mexico , Guatemala , El Salvador , Nicaragua , Honduras and Costa Rica . In rural areas of Nicaragua the disease is colloquially called creatinina . This CKD epidemic in Central America spans along a nearly 1000 kilometer stretch of the Pacific coast . In El Salvador and Nicaragua alone , the reported number of men dying from this painful disease has risen five-fold in the last 20 years , although some researchers believe hidden cases have always been there and this increment in official data could be partially due to the recent increase in reports and improved case search , pushed by the growing social and political interest in the disease . In El Salvador , the disease has become the second leading cause of death among adult men , and according to a recent editorial , it has been estimated that this largely unknown epidemic has caused the premature death of at least 20,000 men in the region . Science Magazine reports : `` In El Salvador alone , PAHO 's latest figures say CKD of all causes kills at least 2,500 people in the country each year '' . The people affected by the epidemic are mainly young and middle-aged male laborers in the agricultural sector , particularly sugarcane workers . The disease has also been found to be prevalent in other occupations with a high risk of heat stress , implying strenuous work ( miners , construction , port and transportation workers ) in the high temperatures of the coastlands . The epidemic appears to affect particular Pacific coastal regions of Nicaragua , El Salvador , Costa Rica , and Guatemala . |
268 | Attribution_of_recent_climate_change | Some scientists believe that solar activity is more likely to influence today's climate than carbon dioxide, and Dr Soon has compiled data showing temperature in America, Canada and Mexico rises and falls in line with solar activity. | Attribution of recent climate change Attribution of recent climate change is the effort to scientifically ascertain mechanisms responsible for recent climate changes on Earth , commonly known as ` global warming ' . The effort has focused on changes observed during the period of instrumental temperature record , when records are most reliable ; particularly in the last 50 years , when human activity has grown fastest and observations of the troposphere have become available . The dominant mechanisms are anthropogenic , i.e. , the result of human activity . They are : increasing atmospheric concentrations of greenhouse gases global changes to land surface , such as deforestation increasing atmospheric concentrations of aerosols . There are also natural mechanisms for variation including climate oscillations , changes in solar activity , and volcanic activity . According to the Intergovernmental Panel on Climate Change ( IPCC ) , it is `` extremely likely '' that human influence was the dominant cause of global warming between 1951 and 2010 . The IPCC defines `` extremely likely '' as indicating a probability of 95 to 100 % , based on an expert assessment of all the available evidence . Multiple lines of evidence support attribution of recent climate change to human activities : A basic physical understanding of the climate system : greenhouse gas concentrations have increased and their warming properties are well-established . Historical estimates of past climate changes suggest that the recent changes in global surface temperature are unusual . Computer-based climate models are unable to replicate the observed warming unless human greenhouse gas emissions are included . Natural forces alone ( such as solar and volcanic activity ) can not explain the observed warming . The IPCC 's attribution of recent global warming to human activities is a view shared by the scientific community , and is also supported by 196 other scientific organizations worldwide ( see also : scientific opinion on climate change ) . |
939 | Antarctica | "Recent computer forecasts suggest that if greenhouse gas emissions continue at a high level, parts of Antarctica could break up rapidly, causing the ocean to rise six feet or more by the end of this century. | Antarctica Antarctica ( UK English -LSB- ænˈtɑːktɪkə -RSB- or -LSB- ænˈtɑːtɪkə -RSB- , US English -LSB- æntˈɑːrktɪkə -RSB- ) is Earth 's southernmost continent . It contains the geographic South Pole and is situated in the Antarctic region of the Southern Hemisphere , almost entirely south of the Antarctic Circle , and is surrounded by the Southern Ocean . At 14000000 km2 , it is the fifth-largest continent . For comparison , Antarctica is nearly twice the size of Australia . About 98 % of Antarctica is covered by ice that averages 1.9 km in thickness , which extends to all but the northernmost reaches of the Antarctic Peninsula . Antarctica , on average , is the coldest , driest , and windiest continent , and has the highest average elevation of all the continents . Antarctica is a desert , with annual precipitation of only 200 mm ( 8 in ) along the coast and far less inland . The temperature in Antarctica has reached − 89.2 ° C ( − 128.6 ° F ) , though the average for the third quarter ( the coldest part of the year ) is − 63 ° C ( − 81 ° F ) . Anywhere from 1,000 to 5,000 people reside throughout the year at the research stations scattered across the continent . Organisms native to Antarctica include many types of algae , bacteria , fungi , plants , protista , and certain animals , such as mites , nematodes , penguins , seals and tardigrades . Vegetation , where it occurs , is tundra . Although myths and speculation about a Terra Australis ( `` Southern Land '' ) date back to antiquity , Antarctica is noted as the last region on Earth in recorded history to be discovered and colonised by humans , being only first sighted in 1820 by the Russian expedition of Fabian Gottlieb von Bellingshausen and Mikhail Lazarev on Vostok and Mirny , who sighted the Fimbul ice shelf . The continent , however , remained largely neglected for the rest of the 19th century because of its hostile environment , lack of easily accessible resources , and isolation . In 1895 , the first confirmed landing was conducted by a team of Norwegians . Antarctica is a de facto condominium , governed by parties to the Antarctic Treaty System that have consulting status . Twelve countries signed the Antarctic Treaty in 1959 , and thirty-eight have signed it since then . The treaty prohibits military activities and mineral mining , prohibits nuclear explosions and nuclear waste disposal , supports scientific research , and protects the continent 's ecozone . Ongoing experiments are conducted by more than 4,000 scientists from many nations . |
2167 | Philosophical_skepticism | Royal Society embraces skepticism | Philosophical skepticism For a general discussion of skepticism , see Skepticism . Philosophical skepticism ( UK spelling scepticism ; from Greek σκέψις skepsis '' , `` inquiry '' ) is both a philosophical school of thought and a method that questions the possibility of certainty in knowledge . It is generally agreed that knowledge requires justification . It is not enough to have a true belief : one must also have good reasons for that belief . Skeptics claim that it is not possible to have an adequate justification . Skepticism is not a single position but covers a range of different positions . In the ancient world there were two main skeptical traditions . Academic skepticism took the dogmatic position that knowledge was not possible ; Pyrrhonian skeptics refused to take a dogmatic position on any issue -- including skepticism . Radical skepticism ends in the paradoxical claim that one can not know anything -- including that one can not know about knowing anything . Skepticism can be classified according to its scope . Local skepticism involves being skeptical about particular areas of knowledge , e.g. moral skepticism , skepticism about the external world , or skepticism about other minds , whereas global skepticism is skeptical about the possibility of any knowledge at all . Skepticism can also be classified according to its method . In the Western tradition there are two basic approaches to skepticism . Cartesian skepticism -- named somewhat misleadingly after René Descartes , who was not a skeptic but used some traditional skeptical arguments in his Meditations to help establish his rationalist approach to knowledge -- attempts to show that any proposed knowledge claim can be doubted . Agrippan skepticism focuses on the process of justification rather than the possibility of doubt . According to this view there are three ways in which one might attempt to justify a claim but none of them are adequate : one can keep on providing further justification but this leads to an infinite regress ; one can stop at a dogmatic assertion ; or one can argue in circular reasoning , never reaching a viable conclusion . Philosophical skepticism is distinguished from methodological skepticism in that philosophical skepticism is an approach that questions the possibility of certainty in knowledge , whereas methodological skepticism is an approach that subjects all knowledge claims to scrutiny with the goal of sorting out true from false claims . |
2948 | Attribution_of_recent_climate_change | Various independent measurements of solar activity all confirm the sun has shown a slight cooling trend since 1978. | Attribution of recent climate change Attribution of recent climate change is the effort to scientifically ascertain mechanisms responsible for recent climate changes on Earth , commonly known as ` global warming ' . The effort has focused on changes observed during the period of instrumental temperature record , when records are most reliable ; particularly in the last 50 years , when human activity has grown fastest and observations of the troposphere have become available . The dominant mechanisms are anthropogenic , i.e. , the result of human activity . They are : increasing atmospheric concentrations of greenhouse gases global changes to land surface , such as deforestation increasing atmospheric concentrations of aerosols . There are also natural mechanisms for variation including climate oscillations , changes in solar activity , and volcanic activity . According to the Intergovernmental Panel on Climate Change ( IPCC ) , it is `` extremely likely '' that human influence was the dominant cause of global warming between 1951 and 2010 . The IPCC defines `` extremely likely '' as indicating a probability of 95 to 100 % , based on an expert assessment of all the available evidence . Multiple lines of evidence support attribution of recent climate change to human activities : A basic physical understanding of the climate system : greenhouse gas concentrations have increased and their warming properties are well-established . Historical estimates of past climate changes suggest that the recent changes in global surface temperature are unusual . Computer-based climate models are unable to replicate the observed warming unless human greenhouse gas emissions are included . Natural forces alone ( such as solar and volcanic activity ) can not explain the observed warming . The IPCC 's attribution of recent global warming to human activities is a view shared by the scientific community , and is also supported by 196 other scientific organizations worldwide ( see also : scientific opinion on climate change ) . |
284 | Global_warming | The figure traditionally cited that suggests 97 per cent of climate scientists agree that global warming is man-made was also found to be flawed. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
784 | Global_warming | "Scientists have published strong evidence that the warming climate is making heat waves more frequent and intense. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
1474 | Global_warming | Etna has already put more than 10,000 times the CO2 into the atmosphere than mankind has in our entire time on the Earth. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
2704 | Australia | Australia accounts for 1.5 per cent of global carbon emissions. | Australia Australia ( -LSB- əˈstreɪliə -RSB- , -LSB- ɒ - -RSB- , -LSB- - ljə -RSB- ) , officially the Commonwealth of Australia , is a country comprising the mainland of the Australian continent , the island of Tasmania and numerous smaller islands . It is the world 's sixth-largest country by total area . The neighbouring countries are Papua New Guinea , Indonesia and East Timor to the north ; the Solomon Islands and Vanuatu to the north-east ; and New Zealand to the south-east . Australia 's capital is Canberra , and its largest urban area is Sydney . For about 50,000 years before the first British settlement in the late 18th century , Australia was inhabited by indigenous Australians , who spoke languages classifiable into roughly 250 groups . After the European discovery of the continent by Dutch explorers in 1606 , Australia 's eastern half was claimed by Great Britain in 1770 and initially settled through penal transportation to the colony of New South Wales from 26 January 1788 . The population grew steadily in subsequent decades , and by the 1850s most of the continent had been explored and an additional five self-governing crown colonies established . On 1 January 1901 , the six colonies federated , forming the Commonwealth of Australia . Australia has since maintained a stable liberal democratic political system that functions as a federal parliamentary constitutional monarchy comprising six states and several territories . The population of 24 million is highly urbanised and heavily concentrated on the eastern seaboard . Australia has the world 's 13th-largest economy and ninth-highest per capita income ( IMF ) . With the second-highest human development index globally , the country ranks highly in quality of life , health , education , economic freedom , and civil liberties and political rights . Australia is a member of the United Nations , G20 , Commonwealth of Nations , ANZUS , Organisation for Economic Co-operation and Development ( OECD ) , World Trade Organization , Asia-Pacific Economic Cooperation , and the Pacific Islands Forum . |
3068 | California | for every renewable energy job that the State manages to finance, Spain's experience...reveals with high confidence, by two different methods, that the U.S. should expect a loss of at least 2.2 jobs on average | California California ( -LSB- kælᵻˈfɔːrnjə , _ - ni.ə -RSB- , ) is the most populous state in the United States and the third most extensive by area . Located on the western ( Pacific Ocean ) coast of the U.S. , California is bordered by the other U.S. states of Oregon , Nevada , and Arizona and shares an international border with the Mexican state of Baja California . The state capital is Sacramento . Los Angeles is California 's most populous city , and the country 's second largest after New York City . The Greater Los Angeles Area and the San Francisco Bay Area are the nation 's second - and fifth-most populous urban regions , respectively . California also has the nation 's most populous county , Los Angeles County , and its largest county by area , San Bernardino County . California 's diverse geography ranges from the Pacific Coast in the west to the Sierra Nevada mountain range in the east ; and from the redwood -- Douglas fir forests in the northwest to the Mojave Desert in the southeast . The Central Valley , a major agricultural area , dominates the state 's center . Though California is well-known for its warm Mediterranean climate , the large size of the state means it can vary from moist temperate rainforest in the north , to arid desert in the interior , as well as snowy alpine in the mountains . What is now California was first settled by various Native American tribes before being explored by a number of European expeditions during the 16th and 17th centuries . The Spanish Empire then claimed it as part of Alta California in their New Spain colony . The area became a part of Mexico in 1821 following its successful war for independence , but was ceded to the United States in 1848 after the Mexican -- American War . The western portion of Alta California then was organized as the State of California , and admitted as the 31st state on September 9 , 1850 . The California Gold Rush starting in 1848 led to dramatic social and demographic changes , with large-scale emigration from the east and abroad with an accompanying economic boom . If it were a country , California would be the 6th largest economy in the world and the 35th most populous . It is also regarded as a global trendsetter in both popular culture and politics , and is the origin of the film industry , the hippie counterculture , the Internet , and the personal computer , among others . Fifty-eight percent of the state 's economy is centered on finance , government , real estate services , technology , and professional , scientific and technical business services . The San Francisco Bay Area has the nation 's highest median household income by metropolitan area , and is the headquarters of three of the world 's largest 40 firms by revenue , Chevron , Apple , and McKesson . Although it accounts for only 1.5 percent of the state 's economy , California 's agriculture industry has the highest output of any U.S. state . |
1286 | Global_warming_controversy | Arctic greening was recently cited, in a major report by the U.S. Geological Survey, as the central reason that the state of Alaska, despite worsening wildfires and more thaw of permafrost, might still be able to stow away more carbon than it loses over the course of the 21st century." | Global warming controversy The global warming controversy concerns the public debate over whether global warming is occurring , how much has occurred in modern times , what has caused it , what its effects will be , whether any action should be taken to curb it , and if so what that action should be . In the scientific literature , there is a strong consensus that global surface temperatures have increased in recent decades and that the trend is caused by human-induced emissions of greenhouse gases . No scientific body of national or international standing disagrees with this view , though a few organizations with members in extractive industries hold non-committal positions . Disputes over the key scientific facts of global warming are more prevalent in the media than in the scientific literature , where such issues are treated as resolved , and such disputes are more prevalent in the United States than globally . Political and popular debate concerning the existence and cause of climate change includes the reasons for the increase seen in the instrumental temperature record , whether the warming trend exceeds normal climatic variations , and whether human activities have contributed significantly to it . Scientists have resolved these questions decisively in favour of the view that the current warming trend exists and is ongoing , that human activity is the cause , and that it is without precedent in at least 2000 years . Public disputes that also reflect scientific debate include estimates of how responsive the climate system might be to any given level of greenhouse gases ( climate sensitivity ) , how global climate change will play out at local and regional scales , and what the consequences of global warming will be . Global warming remains an issue of widespread political debate , often split along party political lines , especially in the United States . Many of the issues that are settled within the scientific community , such as human responsibility for global warming , remain the subject of politically or economically motivated attempts to downplay , dismiss or deny them -- an ideological phenomenon categorised by academics and scientists as climate change denial . The sources of funding for those involved with climate science -- both supporting and opposing mainstream scientific positions -- have been questioned by both sides . There are debates about the best policy responses to the science , their cost-effectiveness and their urgency . Climate scientists , especially in the United States , have reported official and oil-industry pressure to censor or suppress their work and hide scientific data , with directives not to discuss the subject in public communications . Legal cases regarding global warming , its effects , and measures to reduce it have reached American courts . The fossil fuels lobby has been identified as overtly or covertly supporting efforts to undermine or discredit the scientific consensus on global warming . |
2400 | Sustainability | 'To suddenly label CO2 as a "pollutant" is a disservice to a gas that has played an enormous role in the development and sustainability of all life on this wonderful Earth. | Sustainability In ecology , sustainability ( from sustain and ability ) is the property of biological systems to remain diverse and productive indefinite #Adjective . Long-lived and healthy wetlands and forests are examples of sustainable biological systems . In more general terms , sustainability is the endurance of systems and processes . The organizing principle for sustainability is sustainable development , which includes the four interconnected domains : ecology , economics , politics and culture . Sustainability science is the study of sustainable development and environmental science . Sustainability can also be defined as a socio-ecological process characterized by the pursuit of a common ideal . An ideal is by definition unattainable in a given time and space . However , by persistently and dynamically approaching it , the process results in a sustainable system . Healthy ecosystems and environments are necessary to the survival of humans and other organisms . Ways of reducing negative human impact are environmentally-friendly chemical engineering , environmental resources management and environmental protection . Information is gained from green chemistry , earth science , environmental science and conservation biology . Ecological economics studies the fields of academic research that aim to address human economies and natural ecosystems . Moving towards sustainability is also a social challenge that entails international and national law , urban planning and transport , local and individual lifestyles and ethical consumerism . Ways of living more sustainably can take many forms from reorganizing living conditions ( e.g. , ecovillages , eco-municipalities and sustainable cities ) , reappraising economic sectors ( permaculture , green building , sustainable agriculture ) , or work practices ( sustainable architecture ) , using science to develop new technologies ( green technologies , renewable energy and sustainable fission and fusion power ) , or designing systems in a flexible and reversible manner , and adjusting individual lifestyles that conserve natural resources . `` The term ` sustainability ' should be viewed as humanity 's target goal of human-ecosystem equilibrium ( homeostasis ) , while ` sustainable development ' refers to the holistic approach and temporal processes that lead us to the end point of sustainability . '' ( 305 ) Despite the increased popularity of the use of the term `` sustainability '' , the possibility that human societies will achieve environmental sustainability has been , and continues to be , questioned -- in light of environmental degradation , climate change , overconsumption , population growth and societies ' pursuit of unlimited economic growth in a closed system . |
2762 | Mad_(magazine) | One more decade of business as usual will make this impossible. | Mad (magazine) Mad is an American humor magazine founded in 1952 by editor Harvey Kurtzman and publisher William Gaines , launched as a comic book before it became a magazine . It was widely imitated and influential , affecting satirical media as well as the cultural landscape of the 20th century , with editor Al Feldstein increasing readership to more than two million during its 1974 circulation peak . As of January 2017 , Mad has published 544 regular issues , as well as hundreds of reprint `` Specials , '' original material paperbacks , compilation books and other print projects . The magazine is the last surviving title from the EC Comics line , offering satire on all aspects of life and popular culture , politics , entertainment , and public figures . Its format is divided into a number of recurring segments such as TV and movie parodies , as well as freeform articles . Mads mascot , Alfred E. Neuman , is typically the focal point of the magazine 's cover , with his face often replacing that of a celebrity or character who is lampooned within the issue . |
1922 | Homeland_security | More money is dedicated within the Department of Homeland Security to climate change than what's spent combating "Islamist terrorists radicalizing over the Internet in the United States of America." | Homeland security Homeland security is an American umbrella term for `` the national effort to ensure a homeland that is safe , secure , and resilient against terrorism and other hazards where American interests , aspirations , and ways of life can thrive to the national effort to prevent terrorist attacks within the United States , reduce the vulnerability of the U.S. to terrorism , and minimize the damage from attacks that do occur . '' Homeland security is not constrained to terrorist incidents . Terrorism is one of many threats that endanger society . Within the U.S. , an all-hazards approach exists regarding homeland security endeavors . In this sense , homeland security encompasses both natural disasters and man-made events . Thus , the domain of homeland security must accommodate a plethora of situations and scenarios , ranging from natural disasters ( e.g. , Hurricane Katrina ) to acts of terrorism ( e.g. , Boston Marathon bombing ) . The term came about following enactment of the Homeland Security Act of 2002 and reorganization of many U.S. government civil agencies effective March 1 , 2003 , to form the United States Department of Homeland Security after the September 11 attacks , and may be used to refer to the actions of that department , the United States Senate Committee on Homeland Security and Governmental Affairs , or the United States House of Representatives Committee on Homeland Security . Homeland defense ( HD ) is the military protection of U.S. territory , sovereignty , domestic population , and critical infrastructure against external threats and aggression . |
2069 | Global_warming | Rising atmospheric CO2 concentrations are causing ocean acidification, which is catastrophically harming marine life. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
1136 | Coral | When water temperatures become too high, coral becomes stressed and expels the algae, which leave the coral a bleached white color. | Coral Corals are marine invertebrates in the class Anthozoa of phylum Cnidaria . They typically live in compact colonies of many identical individual polyps . The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton . A coral `` group '' is a colony of myriad genetically identical polyps . Each polyp is a sac-like animal typically only a few millimeters in diameter and a few centimeters in length . A set of tentacles surround a central mouth opening . An exoskeleton is excreted near the base . Over many generations , the colony thus creates a large skeleton that is characteristic of the species . Individual heads grow by asexual reproduction of polyps . Corals also breed sexually by spawning : polyps of the same species release gametes simultaneously over a period of one to several nights around a full moon . Although some corals can catch small fish and plankton using stinging cells on their tentacles , most corals obtain the majority of their energy and nutrients from photosynthetic unicellular dinoflagellates in the genus Symbiodinium that live within their tissues . These are commonly known as zooxanthellae and the corals that contain them are zooxanthellate corals . Such corals require sunlight and grow in clear , shallow water , typically at depths shallower than 60 m. Corals are major contributors to the physical structure of the coral reefs that develop in tropical and subtropical waters , such as the enormous Great Barrier Reef off the coast of Queensland , Australia . Other corals do not rely on zooxanthellae and can live in much deeper water , with the cold-water genus Lophelia surviving as deep as 3000 m . Some have been found on the Darwin Mounds , north-west of Cape Wrath , Scotland . Corals have also been found as far north as off the coast of Washington State and the Aleutian Islands . |
2430 | Little_Ice_Age | Even during a period of long term warming, there are short periods of cooling due to climate variability. | Little Ice Age The Little Ice Age ( LIA ) was a period of cooling that occurred after the Medieval Warm Period . Although it was not a true ice age , the term was introduced into scientific literature by François E. Matthes in 1939 . It has been conventionally defined as a period extending from the 16th to the 19th centuries , but some experts prefer an alternative timespan from about 1300 to about 1850 . Climatologists and historians working with local records no longer expect to agree on either the start or end dates of the period , which varied according to local conditions . The NASA Earth Observatory notes three particularly cold intervals : one beginning about 1650 , another about 1770 , and the last in 1850 , all separated by intervals of slight warming . The Intergovernmental Panel on Climate Change Third Assessment Report considered the timing and areas affected by the Little Ice Age suggested largely-independent regional climate changes rather than a globally-synchronous increased glaciation . At most , there was modest cooling of the Northern Hemisphere during the period . Several causes have been proposed : cyclical lows in solar radiation , heightened volcanic activity , changes in the ocean circulation , variations in Earth 's orbit and axial tilt ( orbital forcing ) , inherent variability in global climate , and decreases in the human population . |
2910 | Artificial_intelligence | The authors seem to have jumped right into statistical analysis without proposing a physical mechanism that works. | Artificial intelligence Artificial intelligence ( AI ) is intelligence exhibited by machines . In computer science , the field of AI research defines itself as the study of `` intelligent agents '' : any device that perceives its environment and takes actions that maximize its chance of success at some goal . Colloquially , the term `` artificial intelligence '' is applied when a machine mimics `` cognitive '' functions that humans associate with other human minds , such as `` learning '' and `` problem solving '' . As machines become increasingly capable , mental facilities once thought to require intelligence are removed from the definition . For instance , optical character recognition is no longer perceived as an example of `` artificial intelligence '' , having become a routine technology . Capabilities currently classified as AI include successfully understanding human speech , competing at a high level in strategic game systems ( such as chess and Go ) , self-driving cars , intelligent routing in content delivery networks , military simulations , and interpreting complex data . AI research is divided into subfields that focus on specific problems , approaches , the use of a particular tool , or towards satisfying particular applications . The central problems ( or goals ) of AI research include reasoning , knowledge , planning , learning , natural language processing ( communication ) , perception and the ability to move and manipulate objects . General intelligence is among the field 's long-term goals . Approaches include statistical methods , computational intelligence , and traditional symbolic AI . Many tools are used in AI , including versions of search and mathematical optimization , logic , methods based on probability and economics . The AI field draws upon computer science , mathematics , psychology , linguistics , philosophy , neuroscience , artificial psychology plus many others . The field was founded on the claim that human intelligence `` can be so precisely described that a machine can be made to simulate it '' . This raises philosophical arguments about the nature of the mind and the ethics of creating artificial beings endowed with human-like intelligence , issues which have been explored by myth , fiction and philosophy since antiquity . Some people also consider AI a danger to humanity if it progresses unabatedly . Attempts to create artificial intelligence have experienced many setbacks , including the ALPAC report of 1966 , the abandonment of perceptrons in 1970 , the Lighthill Report of 1973 , the second AI winter 1987 -- 1993 and the collapse of the Lisp machine market in 1987 . In the twenty-first century , AI techniques , both hard ( using a symbolic approach ) and soft ( sub-symbolic ) , have experienced a resurgence following concurrent advances in computer power , sizes of training sets , and theoretical understanding , and AI techniques have become an essential part of the technology industry , helping to solve many challenging problems in computer science . Recent advancements in AI , and specifically in machine learning , have contributed to the growth of Autonomous Things such as drones and self-driving cars , becoming the main driver of innovation in the automotive industry . |
1813 | Population_genetics | Postma's model contains many simple errors; in no way does Postma undermine the existence or necessity of the greenhouse effect. | Population genetics Population genetics is a subfield of genetics that deals with genetic differences within and between populations , and is a part of evolutionary biology . Studies in this branch of biology examine such phenomena as adaptation , speciation , and population structure . Population genetics was a vital ingredient in the emergence of the modern evolutionary synthesis . Its primary founders were Sewall Wright , J. B. S. Haldane and Ronald Fisher , who also laid the foundations for the related discipline of quantitative genetics . Traditionally a highly mathematical discipline , modern population genetics encompasses theoretical , lab , and field work . Population genetic models are used both for statistical inference from DNA sequence data and for proof/disproof of concept . What sets population genetics apart today from newer , more phenotypic approaches to modelling evolution , such as evolutionary game theory and adaptive dynamics , is its emphasis on genetic phenomena as dominance , epistasis , and the degree to which genetic recombination breaks up linkage disequilibrium . This makes it appropriate for comparison to population genomics data . |
1273 | Famine | The rapid changes in the climate may have profound consequences for humans and other species… Severe drought caused food shortages for millions of people in Ethiopia, with a lack of rainfall resulting in "intense and widespread" forest fires in Indonesia that belched out a vast quantity of greenhouse gas | Famine A famine is a widespread scarcity of food , caused by several factors including crop failure , population imbalance , or government policies . This phenomenon is usually accompanied or followed by regional malnutrition , starvation , epidemic , and increased mortality . Every inhabited continent in the world has experienced a period of famine throughout history . In the 19th and 20th century , it was generally Eastern Europe and Asia that suffered the most deaths from famine . The numbers dying from famine began to fall sharply from the 1970s . Some countries , particularly in sub-Saharan Africa , continue to have extreme cases of famine . Since 2010 , Africa has been the most affected continent in the world . As of 2017 , the United Nations has warned some 20 million are at risk in South Sudan , Somalia , Nigeria and Yemen . Agricultural conditions have been fluctuating more and more due to variations in weather , and the distribution of food has been affected by conflict . Most programmes now direct their aid towards Africa . |
101 | Global_warming | Neither the rate nor the magnitude of the reported late twentieth century surface warming (1979–2000) lay outside normal natural variability. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
1487 | Global_warming | NASA has been adjusting temperatures from the past[...] | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
382 | Wind_power | The amount of energy used to construct solar and wind facilities is greater than they produce in their working lives. | Wind power Wind power is the use of air flow through wind turbines to mechanically power generators for electric power . Wind power , as an alternative to burning fossil fuels , is plentiful , renewable , widely distributed , clean , produces no greenhouse gas emissions during operation , consumes no water , and uses little land . The net effects on the environment are far less problematic than those of nonrenewable power sources . Wind farms consist of many individual wind turbines which are connected to the electric power transmission network . Onshore wind is an inexpensive source of electric power , competitive with or in many places cheaper than coal or gas plants . Offshore wind is steadier and stronger than on land , and offshore farms have less visual impact , but construction and maintenance costs are considerably higher . Small onshore wind farms can feed some energy into the grid or provide electric power to isolated off-grid locations . Wind power gives variable power which is very consistent from year to year but which has significant variation over shorter time scales . It is therefore used in conjunction with other electric power sources to give a reliable supply . As the proportion of wind power in a region increases , a need to upgrade the grid , and a lowered ability to supplant conventional production can occur . Power management techniques such as having excess capacity , geographically distributed turbines , dispatchable backing sources , sufficient hydroelectric power , exporting and importing power to neighboring areas , using vehicle-to-grid strategies or reducing demand when wind production is low , can in many cases overcome these problems . In addition , weather forecasting permits the electric power network to be readied for the predictable variations in production that occur . As of 2015 , Denmark generates 40 % of its electric power from wind , and at least 83 other countries around the world are using wind power to supply their electric power grids . In 2014 global wind power capacity expanded 16 % to 369,553 MW . Yearly wind energy production is also growing rapidly and has reached around 4 % of worldwide electric power usage , 11.4 % in the EU . |
126 | Global_warming | El Niño drove record highs in global temperatures suggesting rise may not be down to man-made emissions. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
905 | Indur_M._Goklany | "Some experts, such as UN climate scientist Dr. Indur Goklany, have defended rising CO2 levels as a good thing for humanity. | Indur M. Goklany Indur M. Goklany is a science and technology policy analyst for the United States Department of the Interior , where he holds the position of Assistant Director of Programs , Science and Technology Policy . He has represented the United States at the Intergovernmental Panel on Climate Change ( IPCC ) and during the negotiations that led to the United Nations Framework Convention on Climate Change . He was a rapporteur for the Resource Use and Management Subgroup of Working Group III of the IPCC First Assessment Report in 1990 , and is the author of Clearing the Air ( 1999 ) , The Precautionary Principle ( 2001 ) , and The Improving State of the World ( 2007 ) . |
313 | Effects_of_global_warming_on_humans | Let's find out by comparing the actual temperatures since 1979 with what the 32 families of climate models used in the latest U.N. report on climate science predicted they would be. | Effects of global warming on humans Climate change has brought about possibly permanent alterations to Earth 's geological , biological and ecological systems . These changes have led to the emergence of large-scale environmental hazards to human health , such as extreme weather , ozone depletion , increased danger of wildland fires , loss of biodiversity , stresses to food-producing systems and the global spread of infectious diseases . The World Health Organization ( WHO ) estimates that 160,000 deaths , since 1950 , are directly attributable to climate change . Many believe this to be a conservative estimate . To date , a neglected aspect of the climate change debate , much less research has been conducted on the impacts of climate change on health , food supply , economic growth , migration , security , societal change , and public goods , such as drinking water , than on the geophysical changes related to global warming . Human impacts can be both negative and positive . Climatic changes in Siberia , for instance , are expected to improve food production and local economic activity , at least in the short to medium term . Numerous studies suggest , however , that the current and future impacts of climate change on human society are and will continue to be overwhelmingly negative . The majority of the adverse effects of climate change are experienced by poor and low-income communities around the world , who have much higher levels of vulnerability to environmental determinants of health , wealth and other factors , and much lower levels of capacity available for coping with environmental change . A report on the global human impact of climate change published by the Global Humanitarian Forum in 2009 , estimated more than 300,000 deaths and about $ 125 billion in economic losses each year , and indicating that most climate change induced mortality is due to worsening floods and droughts in developing countries . |
1073 | Climate_change_in_the_Arctic | The amount of summer sea ice in the Arctic has steadily declined over the past few decades because of man-made global warming, according to the National Oceanic and Atmospheric Administration. | Climate change in the Arctic The effects of global warming in the Arctic , or climate change in the Arctic include rising temperatures , loss of sea ice , and melting of the Greenland ice sheet with a related cold temperature anomaly , observed in recent years . Potential methane release from the region , especially through the thawing of permafrost and methane clathrates , is also a concern . The Arctic warms twice as fast compared to the rest of the world . The pronounced warming signal , the amplified response of the Arctic to global warming , it is often seen as a leading indicator of global warming . The melting of Greenland 's ice sheet is linked to polar amplification . According to a study published in 2016 , about 0.5 ◦ C of the warming in the Arctic has been attributed to reductions in sulfate aerosols in Europe since 1980 . |
2821 | Scientific_consensus_on_climate_change | The fact that so many studies on climate change don't bother to endorse the consensus position is significant because scientists have largely moved from what's causing global warming onto discussing details of the problem (eg - how fast, how soon, impacts, etc). | Scientific consensus on climate change There is currently a strong scientific consensus that the Earth is warming and that this warming is mainly caused by human activities. This consensus is supported by various studies of scientists' opinions and by position statements of scientific organizations, many of which explicitly agree with the Intergovernmental Panel on Climate Change (IPCC) synthesis reports. Nearly all actively publishing climate scientists (97–98%) support the consensus on anthropogenic climate change, and the remaining 2% of contrarian studies either cannot be replicated or contain errors. |
1342 | Sea_level_rise | The worsening of tidal flooding in American coastal communities is largely a consequence of greenhouse gases from human activity, and the problem will grow far worse in coming decades, scientists reported Monday. | Sea level rise A sea level rise is an increase in the volume of water in the world 's oceans , resulting in an increase in global mean sea level . Sea level rise is usually attributed to global climate change by thermal expansion of the water in the oceans and by melting of Ice sheets and glaciers on land . Melting of floating ice shelves or icebergs at sea raises sea levels only slightly . Sea level rise at specific locations may be more or less than the global average . Local factors might include tectonic effects , subsidence of the land , tides , currents , storms , etc. . Sea level rise is expected to continue for centuries . Because of the slow inertia , long response time for parts of the climate system , it has been estimated that we are already committed to a sea-level rise of approximately 2.3 m for each degree Celsius of temperature rise within the next 2,000 years . IPCC Summary for Policymakers , AR5 , 2014 , indicated that the global mean sea level rise will continue during the 21st century , very likely at a faster rate than observed from 1971 to 2010 . Projected rates and amounts vary . A January 2017 NOAA report suggests a range of GMSL rise of 0.3 -- 2.5 m possible during the 21st century . Sea level rises can considerably influence human populations in coastal and island regions and natural environments like marine ecosystems . |
1452 | 2000s_(decade) | Most of the warming occurred in the past 35 years, with the five warmest years on record taking place since 2010. | 2000s (decade) The 2000s ( pronounced `` two-thousands '' or `` twenty-hundreds '' ) was a decade of the Gregorian calendar that began on January 1 , 2000 , and ended on December 31 , 2009 . The growth of the Internet contributed to globalization during the decade , which allowed faster communication among people around the world . The economic growth of the 2000s had considerable social , environmental and mass extinction consequences , raised demand for diminishing energy resources , and was still vulnerable , as demonstrated by the financial crisis of 2007 -- 08 . |
2949 | Sunlight | There is no single continuous satellite measurement of Total Solar Irradiance (TSI). | Sunlight Sunlight is a portion of the electromagnetic radiation given off by the Sun , in particular infrared , visible , and ultraviolet light . On Earth , sunlight is filtered through Earth 's atmosphere , and is obvious as daylight when the Sun is above the horizon . When the direct solar radiation is not blocked by clouds , it is experienced as sunshine , a combination of bright light and radiant heat . When it is blocked by clouds or reflects off other objects , it is experienced as diffused light . The World Meteorological Organization uses the term `` sunshine duration '' to mean the cumulative time during which an area receives direct irradiance from the Sun of at least 120 watts per square meter . Other sources indicate an `` Average over the entire earth '' of `` 164 Watts per square meter over a 24 hour day '' . The ultraviolet radiation in sunlight has both positive and negative health effects , as it is both a principal source of vitamin D3 and a mutagen . Sunlight takes about 8.3 minutes to reach Earth from the surface of the Sun . A photon starting at the center of the Sun and changing direction every time it encounters a charged particle would take between 10,000 and 170,000 years to get to the surface . Sunlight is a key factor in photosynthesis , the process used by plants and other autotrophic organisms to convert light energy , normally from the Sun , into chemical energy that can be used to fuel the organisms ' activities . |
2484 | Sea_surface_temperature | The world has entered a 'cold mode' which is likely to bring a global dip in temperatures which will last for 20 to 30 years, they say. | Sea surface temperature Sea surface temperature ( SST ) is the water temperature close to the ocean 's surface . The exact meaning of surface varies according to the measurement method used , but it is between 1 mm and 20 m below the sea surface . Air masses in the Earth 's atmosphere are highly modified by sea surface temperatures within a short distance of the shore . Localized areas of heavy snow can form in bands downwind of warm water bodies within an otherwise cold air mass . Warm sea surface temperatures are known to be a cause of tropical cyclogenesis over the Earth 's oceans . Tropical cyclones can also cause a cool wake , due to turbulent mixing of the upper 30 m of the ocean . SST changes diurnally , like the air above it , but to a lesser degree . There is less SST variation on breezy days than on calm days . In addition , ocean currents such as the Atlantic Multidecadal Oscillation ( AMO ) , can effect SST 's on multi-decadal time scales , a major impact results from the global thermohaline circulation , which affects average SST significantly throughout most of the world 's oceans . Coastal SSTs can cause offshore winds to generate upwelling , which can significantly cool or warm nearby landmasses , but shallower waters over a continental shelf are often warmer . Onshore winds can cause a considerable warm-up even in areas where upwelling is fairly constant , such as the northwest coast of South America . Its values are important within numerical weather prediction as the SST influences the atmosphere above , such as in the formation of sea breezes and sea fog . It is also used to calibrate measurements from weather satellites . |
287 | Global_warming_controversy | Climate skeptics argue temperature records have been adjusted in recent years to make the past appear cooler and the present warmer, although the Carbon Brief showed that NOAA has actually made the past warmer, evening out the difference. | Global warming controversy The global warming controversy concerns the public debate over whether global warming is occurring , how much has occurred in modern times , what has caused it , what its effects will be , whether any action should be taken to curb it , and if so what that action should be . In the scientific literature , there is a strong consensus that global surface temperatures have increased in recent decades and that the trend is caused by human-induced emissions of greenhouse gases . No scientific body of national or international standing disagrees with this view , though a few organizations with members in extractive industries hold non-committal positions . Disputes over the key scientific facts of global warming are more prevalent in the media than in the scientific literature , where such issues are treated as resolved , and such disputes are more prevalent in the United States than globally . Political and popular debate concerning the existence and cause of climate change includes the reasons for the increase seen in the instrumental temperature record , whether the warming trend exceeds normal climatic variations , and whether human activities have contributed significantly to it . Scientists have resolved these questions decisively in favour of the view that the current warming trend exists and is ongoing , that human activity is the cause , and that it is without precedent in at least 2000 years . Public disputes that also reflect scientific debate include estimates of how responsive the climate system might be to any given level of greenhouse gases ( climate sensitivity ) , how global climate change will play out at local and regional scales , and what the consequences of global warming will be . Global warming remains an issue of widespread political debate , often split along party political lines , especially in the United States . Many of the issues that are settled within the scientific community , such as human responsibility for global warming , remain the subject of politically or economically motivated attempts to downplay , dismiss or deny them -- an ideological phenomenon categorised by academics and scientists as climate change denial . The sources of funding for those involved with climate science -- both supporting and opposing mainstream scientific positions -- have been questioned by both sides . There are debates about the best policy responses to the science , their cost-effectiveness and their urgency . Climate scientists , especially in the United States , have reported official and oil-industry pressure to censor or suppress their work and hide scientific data , with directives not to discuss the subject in public communications . Legal cases regarding global warming , its effects , and measures to reduce it have reached American courts . The fossil fuels lobby has been identified as overtly or covertly supporting efforts to undermine or discredit the scientific consensus on global warming . |
1734 | Scenario_planning | Jim Hansen had several possible scenarios; his mid-level scenario B was right. | Scenario planning Scenario planning , also called scenario thinking or scenario analysis , is a strategic planning method that some organizations use to make flexible long-term plans . It is in large part an adaptation and generalization of classic methods used by military intelligence . The original method was that a group of analysts would generate simulation games for policy makers . The games combine known facts about the future , such as demographics , geography , military , political , industrial information , and mineral reserves , with key driving forces identified by considering social , technical , economic , environmental , and political ( STEEP ) trends . In business applications , the emphasis on gaming the behavior of opponents was reduced ( shifting more toward a game against nature ) . At Royal Dutch/Shell for example , scenario planning was viewed as changing mindsets about the exogenous part of the world , prior to formulating specific strategies . Scenario planning may involve aspects of systems thinking , specifically the recognition that many factors may combine in complex ways to create sometime surprising futures ( due to non-linear feedback loops ) . The method also allows the inclusion of factors that are difficult to formalize , such as novel insights about the future , deep shifts in values , unprecedented regulations or inventions . Systems thinking used in conjunction with scenario planning leads to plausible scenario story lines because the causal relationship between factors can be demonstrated . In these cases when scenario planning is integrated with a systems thinking approach to scenario development , it is sometimes referred to as dynamic scenarios . |
168 | Scientific_consensus_on_climate_change | As the temperature has increased, so has the ability of scientists to determine whether specific events are linked to climate change. | Scientific consensus on climate change There is currently a strong scientific consensus that the Earth is warming and that this warming is mainly caused by human activities. This consensus is supported by various studies of scientists' opinions and by position statements of scientific organizations, many of which explicitly agree with the Intergovernmental Panel on Climate Change (IPCC) synthesis reports. Nearly all actively publishing climate scientists (97–98%) support the consensus on anthropogenic climate change, and the remaining 2% of contrarian studies either cannot be replicated or contain errors. |
137 | Intensive_animal_farming | Preventing future pandemics requires more not less "industrial" agriculture | Intensive animal farming Intensive animal farming or industrial livestock production , also known as factory farming by opponents of the practice , is a modern form of intensive farming that refers to animal husbandry , the keeping of livestock such as cattle , poultry , and fish at higher stocking densities than is usually the case with other forms of animal agriculture -- a practice typical in industrial farming by agribusinesses . The main products of this industry are meat , milk and eggs for human consumption . There are issues regarding whether factory farming is sustainable and ethical . Confinement at high stocking density is one part of a systematic effort to produce the highest output at the lowest cost by relying on economies of scale , modern machinery , biotechnology , and global trade . There are differences in the way factory farming techniques are practiced around the world . There is a continuing debate over the benefits , risks and ethical questions of factory farming . The issues include the efficiency of food production ; animal welfare ; whether it is essential for feeding the growing global population ; and the environmental impact ( e.g. pollution ) and health risks . |
3059 | Carbon_dioxide | Models and direct observations find that CFCs only contribute a fraction of the warming supplied by other greenhouse gases. | Carbon dioxide Carbon dioxide ( chemical formula ) is a colorless gas with a density about 60 % higher than that of air ( 1.225 g/L ) that is odorless at normally encountered concentrations . Carbon dioxide consists of a carbon atom covalently double bonded to two oxygen atoms . It occurs naturally in Earth 's atmosphere as a trace gas at a concentration of about 0.04 percent ( 400 ppm ) by volume . Natural sources include volcanoes , hot springs and geysers , and it is freed from carbonate rocks by dissolution in water and acids . Because carbon dioxide is soluble in water , it occurs naturally in groundwater , rivers and lakes , ice caps , glaciers and seawater . It is present in deposits of petroleum and natural gas . As the source of available carbon in the carbon cycle , atmospheric carbon dioxide is the primary carbon source for life on Earth and its concentration in Earth 's pre-industrial atmosphere since late in the Precambrian has been regulated by photosynthetic organisms and geological phenomena . Plants , algae and cyanobacteria use light energy to photosynthesize carbohydrate from carbon dioxide and water , with oxygen produced as a waste product . Carbon dioxide is produced by all aerobic organisms when they metabolize carbohydrates and lipids to produce energy by respiration . It is returned to water via the gills of fish and to the air via the lungs of air-breathing land animals , including humans . Carbon dioxide is produced during the processes of decay of organic materials and the fermentation of sugars in bread , beer and winemaking . It is produced by combustion of wood and other organic materials and fossil fuels such as coal , peat , petroleum and natural gas . It is a versatile industrial material , used , for example , as an inert gas in welding and fire extinguishers , as a pressurizing gas in air guns and oil recovery , as a chemical feedstock and in liquid form as a solvent in decaffeination of coffee and supercritical drying . It is added to drinking water and carbonated beverages including beer and sparkling wine to add effervescence . The frozen solid form of , known as `` dry ice '' is used as a refrigerant and as an abrasive in dry-ice blasting . Carbon dioxide is the most significant long-lived greenhouse gas in Earth 's atmosphere . Since the Industrial Revolution anthropogenic emissions - primarily from use of fossil fuels and deforestation - have rapidly increased its concentration in the atmosphere , leading to global warming . Carbon dioxide also causes ocean acidification because it dissolves in water to form carbonic acid . |
1237 | Last_Glacial_Period | the last sea-level high point, … occurred between the last two ice ages, about 125,000 years ago. | Last Glacial Period The Last Glacial Period (LGP) occurred from the end of the Eemian to the end of the Younger Dryas, encompassing the period c. 115,000 – c. 11,700 years ago. The LGP is part of a larger sequence of glacial and interglacial periods known as the Quaternary glaciation which started around 2,588,000 years ago and is ongoing. The definition of the Quaternary as beginning 2.58 million years ago is based on the formation of the Arctic ice cap. The Antarctic ice sheet began to form earlier, at about 34 Ma, in the mid-Cenozoic (Eocene–Oligocene extinction event). The term Late Cenozoic Ice Age is used to include this early phase.During this last glacial period there were alternating episodes of glacier advance and retreat. Within the last glacial period the Last Glacial Maximum was approximately 22,000 years ago. While the general pattern of global cooling and glacier advance was similar, local differences in the development of glacier advance and retreat make it difficult to compare the details from continent to continent (see picture of ice core data below for differences). Approximately 12,800 years ago, the Younger Dryas, the most recent glacial epoch, began, a coda to the preceding 100,000 year glacial period. Its end about 11,550 years ago marked the beginning of the Holocene, the current geological epoch. From the point of view of human archaeology, the last glacial period falls in the Paleolithic and early Mesolithic periods. When the glaciation event started, Homo sapiens were confined to lower latitudes and used tools comparable to those used by Neanderthals in western and central Eurasia and by Denisovans and Homo erectus in Asia. Near the end of the event, Homo sapiens migrated into Eurasia and Australia. Archaeological and genetic data suggest that the source populations of Paleolithic humans survived the last glacial period in sparsely wooded areas and dispersed through areas of high primary productivity while avoiding dense forest cover. |
2320 | Medieval_Warm_Period | While the Medieval Warm Period saw unusually warm temperatures in some regions, globally the planet was cooler than current conditions. | Medieval Warm Period The Medieval Warm Period ( MWP ) , Medieval Climate Optimum , or Medieval Climatic Anomaly was a time of warm climate in the North Atlantic region that may also have been related to other climate events around the world during that time , including China and other areas , lasting from about 950 to 1250 . It was followed by a cooler period in the North Atlantic and elsewhere termed the Little Ice Age . Some refer to the event as the Medieval Climatic Anomaly as this term emphasizes that effects other than temperature were important . Despite uncertainties , especially for the period prior to 1600 for which data are scarce , the warmest period of the last 2,000 years prior to the 20th century in the Northern Hemisphere very likely occurred between 950 and 1100 . Proxy records show peak warmth occurred at different times for different regions , indicating that the Medieval Warm Period was not a time of globally uniform change . Temperatures in some regions matched or exceeded recent temperatures in these regions , but globally the Medieval Warm Period was cooler than recent global temperatures . Possible causes of the Medieval Warm Period include increased solar activity , decreased volcanic activity , and changes to ocean circulation . |
581 | Sydney | the kind of extreme heat we saw this past summer will be the norm | Sydney Sydney is the state capital of New South Wales and the most populous city in Australia and Oceania . Located on Australia 's east coast , the metropolis surrounds the world 's largest natural harbour , and sprawls towards the Blue Mountains to the west . Residents of Sydney are known as `` Sydneysiders '' . Sydney is the location of the secondary official residences of the Governor-General of Australia and the Prime Minister of Australia , Admiralty House and Kirribilli House respectively . The Sydney area has been inhabited by indigenous Australians for at least 30,000 years . The first British settlers , led by Captain Arthur Phillip , arrived in 1788 to found Sydney as a penal colony , the first European settlement in Australia . Since convict transportation ended in the mid-19th century , the city has transformed from a colonial outpost into a major global cultural and economic centre . As at June 2016 Sydney 's estimated population was 5,005,358 . In the , 34 percent of the population reported having been born overseas , representing many different nationalities and making Sydney one of the most multicultural cities in the world . There are more than 250 different languages spoken in Sydney and about one-third of residents speak a language other than English at home . Despite being one of the most expensive cities in the world , the 2014 Mercer Quality of Living Survey ranks Sydney tenth in the world in terms of quality of living , making it one of the most livable cities . It is classified as an Alpha + World City by the Globalization and World Cities Research Network , indicating its influence in the region and throughout the world . Ranked eleventh in the world for economic opportunity , Sydney has an advanced market economy with strengths in finance , manufacturing and tourism . Its gross regional product was $ 337 billion in 2013 , the largest in Australia . There is a significant concentration of foreign banks and multinational corporations in Sydney and the city is promoted as one of Asia Pacific 's leading financial hubs . In addition to hosting events such as the 2000 Summer Olympics , Sydney is amongst the top fifteen most-visited cities in the world , with millions of tourists coming each year to see the city 's landmarks . Its natural features include Sydney Harbour , the Royal National Park , and the Royal Botanic Garden . Man-made attractions such as the Sydney Opera House , Sydney Tower and the Sydney Harbour Bridge are also well known to international visitors . |
2497 | Aralam_Wildlife_Sanctuary | Without the forests' humidity, previously moisture-laden winds blew dry. | Aralam Wildlife Sanctuary Aralam Wildlife Sanctuary is the northernmost wildlife sanctuary of Kerala , southwest India . It is 55 km2 in area and located on the western slope of the Western Ghats . It was established in 1984 . The headquarters of the sanctuary is near Iritty . Aralam Wildlife Sanctuary is situated in the southeast part of Kannur District . It lies between 11 ° 54 ′ and 11 ° 59 ′ north latitude and 75 ° 47 ′ and 75 ° 57 ′ east longitude . The sanctuary area falls in Aralam , Kelakam and Kottiyoor revenue villages and is located in the northwest slopes of Western Ghats contiguous with the forests of Coorg ( Kodagu ) district of Karnataka state . The PA ( protected area ) consists of Aralam Range , the only range of Aralam wildlife division , which is part of Northern Wildlife Circle ( Northern Region ) Palakkad . The extent of the sanctuary is 55 km2 . The sanctuary was constituted in 1984 as per GO ( P ) 300/84/AD dated 15 October 1984 . It was formed by carving out areas from the Odanthode Malavaram of Thalassery special division which was an erstwhile private forest , subsequently taken over by Govt . as per the provisions of the Kerala Private Forests ( vesting and assignment ) Act 1971 and from the Kottiyoor RF of Wayanad Forest Division . The vested forest portion of the sanctuary is 32.64 km2 and the 22.36 km2 is part of Kottiyoor RF ( Reserved Forest ) . Till 30.6.98 this sanctuary was a range in Wayanad Wildlife Division . It started functioning as an independent wildlife division since 1.7.98 as per GO ( MS ) 36/98 dated 27.5.98 . In the First Management Plan the entire area was divided into two zones viz : the Core Zone and the Buffer Zone.Climatic factors include rainfall , temperature , humidity , frost and so on . Average rainfall : 4000 mm Temperature : 11.0 ° C to 40.0 ° C Humidity : 60 to 100 % Wind : Regular wind during Southwest monsoon Water source : Cheenkannipuzha |
184 | Global_warming | It has never been shown that human emissions of carbon dioxide drive global warming. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
450 | Greenhouse_gas | If we double atmospheric carbon dioxide[…] we'd only raise global surface temperatures by about a degree Celsius. | Greenhouse gas A greenhouse gas ( abbrev . GHG ) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range . This process is the fundamental cause of the greenhouse effect . The primary greenhouse gases in Earth 's atmosphere are water vapor , carbon dioxide , methane , nitrous oxide , and ozone . Without greenhouse gases , the average temperature of Earth 's surface would be about -18 ° C , rather than the present average of 15 ° C . In the Solar System , the atmospheres of Venus , Mars and Titan also contain gases that cause a greenhouse effect . Human activities since the beginning of the Industrial Revolution ( taken as the year 1750 ) have produced a 40 % increase in the atmospheric concentration of carbon dioxide , from 280 ppm in 1750 to 406 ppm in early 2017 . This increase has occurred despite the uptake of a large portion of the emissions by various natural `` sinks '' involved in the carbon cycle . Anthropogenic carbon dioxide emissions ( i.e. , emissions produced by human activities ) come from combustion of fossil fuels , principally coal , oil , and natural gas , along with deforestation , soil erosion and animal agriculture . It has been estimated that if greenhouse gas emissions continue at the present rate , Earth 's surface temperature could exceed historical values as early as 2047 , with potentially harmful effects on ecosystems , biodiversity and the livelihoods of people worldwide . Recent estimates suggest that on the current emissions trajectory the Earth could pass a threshold of 2 ° C global warming , which the United Nations ' IPCC designated as the upper limit to avoid `` dangerous '' global warming , by 2036 . |
307 | Deforestation | For instance, wind turbines kill birds and insects, and palm-oil plantations destroy the biodiversity of the rainforests | Deforestation Deforestation , clearance or clearing is the removal of a forest or stand of trees where the land is thereafter converted to a non-forest use . Examples of deforestation include conversion of forestland to farms , ranches , or urban use . The most concentrated deforestation occurs in tropical rainforests . About 30 % of Earth 's land surface is covered by forests . Deforestation occurs for multiple reasons : trees are cut down to be used for building or sold as fuel , ( sometimes in the form of charcoal or timber ) , while cleared land is used as pasture for livestock and plantation . The removal of trees without sufficient reforestation has resulted in damage to habitat , biodiversity loss and aridity . It has adverse impacts on biosequestration of atmospheric carbon dioxide . Deforestation has also been used in war to deprive the enemy of vital resources and cover for its forces . Modern examples of this were the use of Agent Orange by the British military in Malaya during the Malayan Emergency and the United States military in Vietnam during the Vietnam War . As of 2005 , net deforestation rates have ceased to increase in countries with a per capita GDP of at least US$ 4,600 . Deforested regions typically incur significant adverse soil erosion and frequently degrade into wasteland . Disregard of ascribed value , lax forest management and deficient environmental laws are some of the factors that allow deforestation to occur on a large scale . In many countries , deforestation , both naturally occurring and human-induced , is an ongoing issue . Deforestation causes extinction , changes to climatic conditions , desertification , and displacement of populations as observed by current conditions and in the past through the fossil record . More than half of all plant and land animal species in the world live in tropical forests . Between 2000 and 2012 , 2.3 e6sqkm of forests around the world were cut down . As a result of deforestation , only 6.2 e6km2 remain of the original 16 e6km2 of forest that formerly covered the Earth . |
516 | Earth | For the past 4567 million years, the sun and the Earth's orbit have driven climate change cycles. | Earth Earth ( from Eorðe -LSB- Γαῖα , Gaia -RSB- Terra ) , otherwise known as the World or the Globe , is the third planet from the Sun and the only object in the Universe known to harbor life . It is the densest planet in the Solar System and the largest of the four terrestrial planets . According to radiometric dating and other sources of evidence , Earth formed about 4.54 billion years ago . Earth 's gravity interacts with other objects in space , especially the Sun and the Moon , Earth 's only natural satellite . During one orbit around the Sun , Earth rotates about its axis over 365 times ; thus , an Earth year is about 365.26 days long . Earth 's axis of rotation is tilted , producing seasonal variations on the planet 's surface . The gravitational interaction between the Earth and Moon causes ocean tides , stabilizes the Earth 's orientation on its axis , and gradually slows its rotation . Earth 's lithosphere is divided into several rigid tectonic plates that migrate across the surface over periods of many millions of years . About 71 % of Earth 's surface is covered with water , mostly by its oceans . The remaining 29 % is land consisting of continents and islands that together have many lakes , rivers and other sources of water that contribute to the hydrosphere . The majority of Earth 's polar regions are covered in ice , including the Antarctic ice sheet and the sea ice of the Arctic ice pack . Earth 's interior remains active with a solid iron inner core , a liquid outer core that generates the Earth 's magnetic field , and a convecting mantle that drives plate tectonics . Within the first billion years of Earth 's history , life appeared in the oceans and began to affect the Earth 's atmosphere and surface , leading to the proliferation of aerobic and anaerobic organisms . Some geological evidence indicates that life may have arisen as much as 4.1 billion years ago . Since then , the combination of Earth 's distance from the Sun , physical properties , and geological history have allowed life to evolve and thrive . In the history of the Earth , biodiversity has gone through long periods of expansion , occasionally punctuated by mass extinction events . Over 99 % of all species that ever lived on Earth are extinct . Estimates of the number of species on Earth today vary widely ; most species have not been described . Over 7.4 billion humans live on Earth and depend on its biosphere and minerals for their survival . Humans have developed diverse societies and cultures ; politically , the world has about 200 sovereign states . |
736 | Europa_(moon) | But the new research shows that the amount of oxygen in those shells doesn't actually remain constant over time. | Europa (moon) Europa -LSB- jʊˈroʊpə -RSB- ( Jupiter II ) , is the smallest of the four Galilean moons orbiting Jupiter , and the sixth-closest to the planet . It is also the sixth-largest moon in the Solar System . Europa was discovered in 1610 by Galileo Galilei and was named after Europa , the legendary mother of King Minos of Crete and lover of Zeus ( the Greek equivalent of the Roman god Jupiter ) . Slightly smaller than Earth 's Moon , Europa is primarily made of silicate rock and has a water-ice crust and probably an iron -- nickel core . It has a tenuous atmosphere composed primarily of oxygen . Its surface is striated by cracks and streaks , whereas craters are relatively rare . In addition to Earth-bound telescope observations , Europa has been examined by a succession of space probe flybys , the first occurring in the early 1970s . Europa has the smoothest surface of any known solid object in the Solar System . The apparent youth and smoothness of the surface have led to the hypothesis that a water ocean exists beneath it , which could conceivably harbor extraterrestrial life . The predominant model suggests that heat from tidal flexing causes the ocean to remain liquid and drives ice movement similar to plate tectonics , absorbing chemicals from the surface into the ocean below . Sea salt from a subsurface ocean may be coating some geological features on Europa , suggesting that the ocean is interacting with the seafloor . This may be important in determining if Europa could be habitable . In addition , the Hubble Space Telescope detected water vapor plumes similar to those observed on Saturn 's moon Enceladus , which are thought to be caused by erupting cryogeysers . The Galileo mission , launched in 1989 , provides the bulk of current data on Europa . No spacecraft has yet landed on Europa , although there have been several proposed exploration missions . The European Space Agency 's Jupiter Icy Moon Explorer ( JUICE ) is a mission to Ganymede that is due to launch in 2022 , and will include two flybys of Europa . NASA 's planned Europa Clipper will be launched in the mid-2020s . |
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