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3127 | Physics | "Skeptics hope that Postma's alternative thermal model will lead to the birth of a new climatology, one that actually follows the laws of physics and properly physical modeling techniques... | Physics Physics ( from -LSB- φυσική , phusikḗ ( epistḗmē ) , knowledge of nature -RSB- , from φύσις phúsis `` nature '' ) is the natural science that involves the study of matter and its motion and behavior through space and time , along with related concepts such as energy and force . One of the most fundamental scientific disciplines , the main goal of physics is to understand how the universe behaves . Physics is one of the oldest academic disciplines , perhaps the oldest through its inclusion of astronomy . Over the last two millennia , physics was a part of natural philosophy along with chemistry , biology , and certain branches of mathematics , but during the scientific revolution in the 17th century , the natural sciences emerged as unique research programs in their own right . Physics intersects with many interdisciplinary areas of research , such as biophysics and quantum chemistry , and the boundaries of physics are not rigidly defined . New ideas in physics often explain the fundamental mechanisms of other sciences while opening new avenues of research in areas such as mathematics and philosophy . Physics also makes significant contributions through advances in new technologies that arise from theoretical breakthroughs . For example , advances in the understanding of electromagnetism or nuclear physics led directly to the development of new products that have dramatically transformed modern-day society , such as television , computers , domestic appliances , and nuclear weapons ; advances in thermodynamics led to the development of industrialization , and advances in mechanics inspired the development of calculus . The United Nations named 2005 the World Year of Physics . |
2071 | Air_pollution | Carbon pollution is a health hazard. | Air pollution Air pollution occurs when harmful substances including particulates and biological molecules are introduced into Earth 's atmosphere . It may cause diseases , allergies or death in humans ; it may also cause harm to other living organisms such as animals and food crops , and may damage the natural or built environment . Human activity and natural processes can both generate air pollution . Indoor air pollution and poor urban air quality are listed as two of the world 's worst toxic pollution problems in the 2008 Blacksmith Institute World 's Worst Polluted Places report . According to the 2014 WHO report , air pollution in 2012 caused the deaths of around 7 million people worldwide , an estimate roughly matched by the International Energy Agency . |
243 | Scientific_consensus_on_climate_change | In its 5th assessment report in 2013, the IPCC estimated that human emissions are probably responsible for more than half of the observed increase in global average temperature from 1951 to 2010. | 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. |
1259 | Western_United_States | While the north-east, midwest and upper great plains have experienced a 30% increase in heavy rainfall episodes – considered once-in-every-five year downpours – parts of the west, particularly California, have been parched by drought. | Western United States The Western United States , commonly referred to as the American West , the Far West , or simply the West , traditionally refers to the region comprising the westernmost states of the United States . Because European settlement in the U.S. expanded westward after its founding , the meaning of the West has evolved over time . Prior to about 1800 , the crest of the Appalachian Mountains was seen as the western frontier . Since then , the frontier generally moved westward and eventually lands west of the Mississippi River came to be referred to as the West . Though no consensus exists , even among experts , for the definition of the West as a region , the U.S. Census Bureau 's definition of the 13 westernmost states includes the Rocky Mountains and the Great Basin to the West Coast , and the outlying states of Hawaii and Alaska . The West contains several major biomes . It is known for arid to semi-arid plateaus and plains , particularly in the American Southwest -- forested mountains , including the major ranges of the American Sierra Nevada and Rocky Mountains -- the massive coastal shoreline of the American Pacific Coast -- and the rainforests of the Pacific Northwest . |
1675 | Sea_level_rise | The most recent satellite data show that the earth as a whole is warming. | 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 . |
656 | Arctic | The Arctic's carbon bomb might be even more potent than we thought […] methane, a shorter-lived but far harder-hitting gas that could cause faster bursts of warming | Arctic The Arctic ( -LSB- ˈɑrktɪk -RSB- or -LSB- ˈɑrtɪk -RSB- ) is a polar region located at the northernmost part of Earth . The Arctic consists of the Arctic Ocean , adjacent seas , and parts of Alaska ( United States ) , Canada , Finland , Greenland ( Denmark ) , Iceland , Norway , Russia and Sweden . Land within the Arctic region has seasonally varying snow and ice cover , with predominantly treeless permafrost-containing tundra . Arctic seas contain seasonal sea ice in many places . The Arctic region is a unique area among Earth 's ecosystems . For example , the cultures in the region and the Arctic indigenous peoples have adapted to its cold and extreme conditions . In recent years , Arctic sea ice decline has been caused by global warming . Life in the Arctic includes organisms living in the ice , zooplankton and phytoplankton , fish and marine mammals , birds , land animals , plants and human societies . Arctic land is bordered by the subarctic . |
1857 | Hurricane_Katrina | As president, Obama will immediately close the Mississippi River Gulf Outlet, which experts say funneled floodwater into New Orleans. | Hurricane Katrina Hurricane Katrina was the costliest natural disaster and one of the five deadliest hurricanes in the history of the United States . The storm is currently ranked as the third most intense United States landfalling tropical cyclone , behind only the 1935 Labor Day hurricane and Hurricane Camille in 1969 . Overall , at least 1,245 people died in the hurricane and subsequent floods , making it the deadliest United States hurricane since the 1928 Okeechobee hurricane . Total property damage was estimated at $ 108 billion ( 2005 USD ) , roughly four times the damage wrought by Hurricane Andrew in 1992 in the United States . The eleventh named storm and fifth hurricane of the 2005 Atlantic hurricane season , Katrina originated over the Bahamas on August 23 from the interaction between a tropical wave and the remnants of Tropical Depression Ten . Early the following day , the new depression intensified into Tropical Storm Katrina . The cyclone headed generally westward toward Florida and strengthened into a hurricane only two hours before making landfall at Hallandale Beach and Aventura on August 25 . After very briefly weakening to a tropical storm , Katrina emerged into the Gulf of Mexico on August 26 and began to rapidly deepen . The storm strengthened to a Category 5 hurricane over the warm waters of the Gulf of Mexico , but weakened before making its second landfall as a Category 3 hurricane on August 29 in southeast Louisiana . The storm caused severe destruction along the Gulf coast from central Florida to Texas , much of it due to the storm surge and levee failure . Severe property damage occurred in coastal areas , such as Mississippi beachfront towns ; over 90 percent of these were flooded . Boats and casino barges rammed buildings , pushing cars and houses inland ; water reached 6 - from the beach . Over fifty breaches in New Orleans 's hurricane surge protection were the cause of the majority of the death and destruction during Katrina on August 29 , 2005 . Eventually 80 % of the city and large tracts of neighboring parishes became flooded , and the floodwaters lingered for weeks . According to a modeling exercise conducted by the U.S. Army Corps of Engineers ( USACE ) , two-thirds of the deaths in Greater New Orleans were due to levee and floodwall failure . All of the major studies concluded that the USACE , the designers and builders of the levee system as mandated by the Flood Control Act of 1965 , is responsible . This is mainly due to a decision to use shorter steel sheet pilings in an effort to save money . In January 2008 , Judge Stanwood Duval , U.S. District Court , ruled that despite the Corps ' role in the flooding , the agency could not be held financially liable because of sovereign immunity in the Flood Control Act of 1928 . Exactly ten years after Katrina , J. David Rogers , lead author of a new report in the official journal of the World Water Council concluded that the flooding during Katrina `` could have been prevented had the corps retained an external review board to double-check its flood-wall designs . '' There was also an investigation of the responses from federal , state and local governments , resulting in the resignation of Federal Emergency Management Agency ( FEMA ) director Michael D. Brown , and of New Orleans Police Department ( NOPD ) Superintendent Eddie Compass . Many other government officials were criticized for their responses , especially New Orleans Mayor Ray Nagin , Louisiana Governor Kathleen Blanco , and President George W. Bush . Several agencies including the United States Coast Guard ( USCG ) , National Hurricane Center ( NHC ) , and National Weather Service ( NWS ) were commended for their actions . They provided accurate hurricane weather tracking forecasts with sufficient lead time . |
340 | Scientific_consensus_on_climate_change | Heatwaves occur in any climate, but we know that heatwaves are becoming much more likely due 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. |
2165 | Global_warming_controversy | Ben Santer rewrote the 1995 IPCC report | 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 . |
1133 | Earth | Global average temperatures over land have plummeted by more than 1C since the middle of this year – their biggest and steepest fall on record. | 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 . |
2510 | Pacific_decadal_oscillation | In 1946, PDO switched to a cool phase. | Pacific decadal oscillation The Pacific Decadal Oscillation ( PDO ) is a robust , recurring pattern of ocean-atmosphere climate variability centered over the mid-latitude Pacific basin . The PDO is detected as warm or cool surface waters in the Pacific Ocean , north of 20 ° N. Over the past century , the amplitude of this climate pattern has varied irregularly at interannual-to-interdecadal time scales ( meaning time periods of a few years to as much as time periods of multiple decades ) . There is evidence of reversals in the prevailing polarity ( meaning changes in cool surface waters versus warm surface waters within the region ) of the oscillation occurring around 1925 , 1947 , and 1977 ; the last two reversals corresponded with dramatic shifts in salmon production regimes in the North Pacific Ocean . This climate pattern also affects coastal sea and continental surface air temperatures from Alaska to California . During a `` warm '' , or `` positive '' , phase , the west Pacific becomes cooler and part of the eastern ocean warms ; during a `` cool '' or `` negative '' phase , the opposite pattern occurs . The Pacific Decadal Oscillation was named by Steven R. Hare , who noticed it while studying salmon production pattern results in 1997 . The Pacific Decadal Oscillation index is the leading empirical orthogonal function ( EOF ) of monthly sea surface temperature anomalies ( SST-A ) over the North Pacific ( poleward of 20 ° N ) after the global average sea surface temperature has been removed . This PDO index is the standardized principal component time series . A PDO ` signal ' has been reconstructed to 1661 through tree-ring chronologies in the Baja California area . |
307 | Wind_turbine | For instance, wind turbines kill birds and insects, and palm-oil plantations destroy the biodiversity of the rainforests | Wind turbine A wind turbine is a device that converts the wind 's kinetic energy into electrical power . Wind turbines are manufactured in a wide range of vertical and horizontal axis types . The smallest turbines are used for applications such as battery charging for auxiliary power for boats or caravans or to power traffic warning signs . Slightly larger turbines can be used for making contributions to a domestic power supply while selling unused power back to the utility supplier via the electrical grid . Arrays of large turbines , known as wind farms , are becoming an increasingly important source of intermittent renewable energy and are used by many countries as part of a strategy to reduce their reliance on fossil fuels . |
2630 | Atmosphere_of_Jupiter | "A new storm and a new red spot on Jupiter hints at climate change, USA TODAY and dozens of other sources explained yesterday. | Atmosphere of Jupiter The atmosphere of Jupiter is the largest planetary atmosphere in the Solar System . It is mostly made of molecular hydrogen and helium in roughly solar proportions ; other chemical compounds are present only in small amounts and include methane , ammonia , hydrogen sulfide and water . Although water is thought to reside deep in the atmosphere , its directly measured concentration is very low . The nitrogen , sulfur , and noble gas abundances in Jupiter 's atmosphere exceed solar values by a factor of about three . The atmosphere of Jupiter lacks a clear lower boundary and gradually transitions into the liquid interior of the planet . From lowest to highest , the atmospheric layers are the troposphere , stratosphere , thermosphere and exosphere . Each layer has characteristic temperature gradients . The lowest layer , the troposphere , has a complicated system of clouds and hazes , comprising layers of ammonia , ammonium hydrosulfide and water . The upper ammonia clouds visible at Jupiter 's surface are organized in a dozen zonal bands parallel to the equator and are bounded by powerful zonal atmospheric flows ( winds ) known as jets . The bands alternate in color : the dark bands are called belts , while light ones are called zones . Zones , which are colder than belts , correspond to upwellings , while belts mark descending air . The zones ' lighter color is believed to result from ammonia ice ; what gives the belts their darker colors is uncertain . The origins of the banded structure and jets are not well understood , though a `` shallow model '' and a `` deep model '' exist . The Jovian atmosphere shows a wide range of active phenomena , including band instabilities , vortices ( cyclones and anticyclones ) , storms and lightning . The vortices reveal themselves as large red , white or brown spots ( ovals ) . The largest two spots are the Great Red Spot ( GRS ) and Oval BA , which is also red . These two and most of the other large spots are anticyclonic . Smaller anticyclones tend to be white . Vortices are thought to be relatively shallow structures with depths not exceeding several hundred kilometers . Located in the southern hemisphere , the GRS is the largest known vortex in the Solar System . It could engulf two or three Earths and has existed for at least three hundred years . Oval BA , south of GRS , is a red spot a third the size of GRS that formed in 2000 from the merging of three white ovals . Jupiter has powerful storms , often accompanied by lightning strikes . The storms are a result of moist convection in the atmosphere connected to the evaporation and condensation of water . They are sites of strong upward motion of the air , which leads to the formation of bright and dense clouds . The storms form mainly in belt regions . The lightning strikes on Jupiter are hundreds of times more powerful than those seen on Earth . However , there are so few , that the amount of lightning activity is comparable to Earth . |
1383 | Agriculture | a new study by a leading climate economist, Richard Tol of the University of Sussex, concludes that warming may well bring gains, because carbon dioxide causes crops and wild ecosystems to grow greener and more drought-resistant. | Agriculture Agriculture or farming is the cultivation and breeding of animals , plants and fungi for food , fiber , biofuel , medicinal plants and other products used to sustain and enhance human life . Agriculture was the key development in the rise of sedentary human civilization , whereby farming of domesticated species created food surpluses that nurtured the development of civilization . The study of agriculture is known as agricultural science . The history of agriculture dates back thousands of years , and its development has been driven and defined by greatly different climates , cultures , and technologies . Industrial agriculture based on large-scale monoculture farming has become the dominant agricultural methodology . Modern agronomy , plant breeding , agrochemicals such as pesticides and fertilizers , and technological developments have in many cases sharply increased yields from cultivation , but at the same time have caused widespread ecological damage and negative human health effects . Selective breeding and modern practices in animal husbandry have similarly increased the output of meat , but have raised concerns about animal welfare and the health effects of the antibiotics , growth hormones , and other chemicals commonly used in industrial meat production . Genetically modified organisms are an increasing component of agriculture , although they are banned in several countries . Agricultural food production and water management are increasingly becoming global issues that are fostering debate on a number of fronts . Significant degradation of land and water resources , including the depletion of aquifers , has been observed in recent decades , and the effects of global warming on agriculture and of agriculture on global warming are still not fully understood . The major agricultural products can be broadly grouped into foods , fibers , fuels , and raw materials . Specific foods include cereals ( grains ) , vegetables , fruits , oils , meats and spices . Fibers include cotton , wool , hemp , silk and flax . Raw materials include lumber and bamboo . Other useful materials are also produced by plants , such as resins , dyes , drugs , perfumes , biofuels and ornamental products such as cut flowers and nursery plants . Over one third of the world 's workers are employed in agriculture , second only to the service sector , although the percentages of agricultural workers in developed countries has decreased significantly over the past several centuries . |
506 | Intergovernmental_Panel_on_Climate_Change | More than 100 climate models over the past 30 years did not predict what actually happened because it was assumed carbon dioxide had the pivotal role in driving climate change and that the effects of clouds, back-radiation and the sun were trivial. | 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 . |
2391 | Greenland | Greenland on the whole is losing ice, as confirmed by multiple satellite and on the ground field measurements. | Greenland Greenland ( -LSB- ˈɡriːnlənd -RSB- Kalaallit Nunaat -LSB- kaˈlaːɬit ˈnunaːt -RSB- Grønland -LSB- ˈɡ̊ʁɶnˌlanˀ -RSB- ) is an autonomous constituent country within the Kingdom of Denmark between the Arctic and Atlantic Oceans , east of the Canadian Arctic Archipelago . Though physiographically a part of the continent of North America , Greenland has been politically and culturally associated with Europe ( specifically Norway and Denmark , the colonial powers , as well as the nearby island of Iceland ) for more than a millennium . The majority of its residents are Inuit , whose ancestors began migrating from the Canadian mainland in the 13th century , gradually settling across the island . Greenland is the world 's largest island ( Australia , although larger , is generally considered to be a continental landmass rather than an island ) . Three-quarters of Greenland is covered by the only permanent ice sheet outside Antarctica . With a population of about 56,480 ( 2013 ) , it is the least densely populated country in the world . The Arctic Umiaq Line ferry acts as a lifeline for western Greenland , connecting the various cities and settlements . Greenland has been inhabited off and on for at least the last 4,500 years by Arctic peoples whose forebears migrated there from what is now Canada . Norsemen settled the uninhabited southern part of Greenland beginning in the 10th century , and Inuit peoples arrived in the 13th century . The Norse colonies disappeared in the late 15th century . Soon after their demise , beginning in 1499 , the Portuguese briefly explored and claimed the island , naming it Terra do Lavrador ( later applied to Labrador in Canada ) . In the early 18th century , Scandinavian explorers reached Greenland again . To strengthen trading and power , Denmark-Norway affirmed sovereignty over the island . Denmark -- Norway claimed Greenland for centuries . Greenland was settled by Vikings ( of Norwegian origin ) more than a thousand years ago , who had previously settled Iceland to escape persecution from the King of Norway and his central government . Vikings set sail from Greenland and Iceland , encountering North America nearly 500 years before Columbus reached the Caribbean islands . They attempted to colonize land . Though under continuous influence of Norway and Norwegians , Greenland was not formally under the Norwegian crown until 1262 . The Kingdom of Norway was extensive and a military power until the mid-14th century . Norway was dramatically hit with a larger death toll than Denmark by the Black Death , forcing Norway to accept a union in which the central government , university and other fundamental institutions were located in Copenhagen . Thus , the two kingdoms ' resources were directed at creating Copenhagen . Norway became the weaker part and lost sovereignty over Greenland in 1814 when the union was dissolved . Greenland became a Danish colony in 1814 , and was made a part of the Danish Realm in 1953 under the Constitution of Denmark . In 1973 , Greenland joined the European Economic Community with Denmark . However , in a referendum in 1982 , a majority of the population voted for Greenland to withdraw from the EEC which was effected in 1985 . Greenland contains the world 's largest and most northernly national park , Northeast Greenland National Park ( Kalaallit Nunaanni nuna eqqissisimatitaq ) . Established in 1974 and expanded to its present size in 1988 , it protects 972001 km2 of the interior and northeastern coast of Greenland and is bigger than all but twenty-nine countries in the world . Greenland is divided into four municipalities - Sermersooq , Kujalleq , Qaasuitsup , and Qeqqata . In 1979 , Denmark had granted home rule to Greenland , and in 2008 , Greenlanders voted in favour of the Self-Government Act , which transferred more power from the Danish royal government to the local Greenlandic government . Under the new structure , in effect since 21 June 2009 , Greenland can gradually assume responsibility for policing , judicial system , company law , accounting , and auditing ; mineral resource activities ; aviation ; law of legal capacity , family law and succession law ; aliens and border controls ; the working environment ; and financial regulation and supervision , while the Danish government retains control of foreign affairs and defence . It also retains control of monetary policy , providing an initial annual subsidy of DKK 3.4 billion , which is planned to diminish gradually over time . Greenland expects to grow its economy based on increased income from the extraction of natural resources . The capital , Nuuk , held the 2016 Arctic Winter Games . At 70 % , Greenland has one of the highest shares of renewable energy in the world , mostly coming from hydropower . |
2768 | Albedo | The long term trend from albedo is that of cooling. | Albedo Albedo ( -LSB- ælˈbiːdoʊ -RSB- ) is a measure for reflectance or optical brightness ( Latin albedo , Arabic albayad , `` whiteness '' ) . It is dimensionless and measured on a scale from zero ( corresponding to a black body that absorbs all incident radiation ) to one ( corresponding to a white body that reflects all incident radiation ) . Surface albedo is defined as the ratio of radiation reflected to the radiation incident on a surface . The proportion reflected is not only determined by properties of the surface itself , but also by the spectral and angular distribution of solar radiation reaching the Earth 's surface . These factors vary with atmospheric composition , geographic location and time ( see Position of the Sun ) . While bi-hemispherical reflectance is calculated for a single angle of incidence ( i.e. , for a given position of the sun ) , albedo is the directional integration of reflectance over all solar angles in a given period . The temporal resolution may range from seconds ( as obtained from flux measurements ) to daily , seasonal or annual averages . Unless given for a specific wavelength ( spectral albedo ) , albedo refers to the entire spectrum of solar radiation . Due to measurement constraints , it is often given for the spectrum in which most solar energy reaches the surface ( approximately between 0.3 and 3 μm ) . This spectrum includes visible light ( 0.39-0 .7 μm ) , which explains why surfaces with a low albedo appear dark ( e.g. , trees absorb most radiation ) , whereas surfaces with a high albedo appear bright ( e.g. , snow reflects most radiation ) . Albedo is an important concept in climatology , astronomy , and environmental management ( e.g. , as part of the Leadership in Energy and Environmental Design ( LEED ) program for sustainable rating of buildings ) . The average albedo of the Earth at the top of the atmosphere , its planetary albedo , is 30 to 35 % because of cloud cover , but widely varies locally across the surface because of different geological and environmental features . The term albedo was introduced into optics by Johann Heinrich Lambert in his 1760 work Photometria . |
2489 | Antarctica | "Three Australasian researchers have shown that natural forces are the dominant influence on climate, in a study just published in the highly-regarded Journal of Geophysical Research. | 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 . |
2803 | Global_warming | When we do the calculations and include all radiative forcings and the amount of heat being absorbed by the oceans, it shows that the Earth has warmed almost exactly as much as we would expect. | 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 . |
697 | Global_warming_controversy | While many scientists have acknowledged the mismatch between model predictions and actual temperature observations, few have really challenged the validity of the models themselves. | 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 . |
2520 | Thermodynamic_equilibrium | According to the second law of thermodynamics such a planetary machine can never exist." | Thermodynamic equilibrium Thermodynamic equilibrium is an axiomatic concept of thermodynamics . It is an internal state of a single thermodynamic system , or a relation between several thermodynamic systems connected by more or less permeable or impermeable walls . In thermodynamic equilibrium there are no net macroscopic flows of matter or of energy , either within a system or between systems . In a system in its own state of internal thermodynamic equilibrium , no macroscopic change occurs . Systems in mutual thermodynamic equilibrium are simultaneously in mutual thermal , mechanical , chemical , and radiative equilibria . Systems can be in one kind of mutual equilibrium , though not in others . In thermodynamic equilibrium , all kinds of equilibrium hold at once and indefinitely , until disturbed by a thermodynamic operation . In a macroscopic equilibrium , almost or perfectly exactly balanced microscopic exchanges occur ; this is the physical explanation of the notion of macroscopic equilibrium . A thermodynamic system in its own state of internal thermodynamic equilibrium has a spatially uniform temperature . Its intensive properties , other than temperature , may be driven to spatial inhomogeneity by an unchanging long range force field imposed on it by its surroundings . In non-equilibrium systems , by contrast , there are net flows of matter or energy . If such changes can be triggered to occur in a system in which they are not already occurring , it is said to be in a metastable equilibrium . Though it is not a widely named law , it is an axiom of thermodynamics that there exist states of thermodynamic equilibrium . The second law of thermodynamics states that when a body of material starts from an equilibrium state , in which portions of it are held at different states by more or less permeable or impermeable partitions , and a thermodynamic operation removes or makes the partitions more permeable and it is isolated , then it spontaneously reaches its own new state of internal thermodynamic equilibrium , and this is accompanied by an increase in the sum of the entropies of the portions . |
1549 | Biodiversity | There's no empirical evidence for climate change. | Biodiversity Biodiversity a portmanteau of `` biological diversity , '' generally refers to the variety and variability of life on Earth . According to the United Nations Environment Programme , biodiversity typically measures variation at the genetic , the species , and the ecosystem level . Terrestrial biodiversity tends to be greater near the equator , which seems to be the result of the warm climate and high primary productivity . Biodiversity is not distributed evenly on Earth , and is richest in the tropics . These tropical forest ecosystems cover less than 10 per cent of earth 's surface , and contain about 90 percent of the world 's species . Marine biodiversity tends to be highest along coasts in the Western Pacific , where sea surface temperature is highest and in the mid-latitudinal band in all oceans . There are latitudinal gradients in species diversity . Biodiversity generally tends to cluster in hotspots , and has been increasing through time , but will be likely to slow in the future . Rapid environmental changes typically cause mass extinctions . More than 99.9 percent of all species , amounting to over five billion species , that ever lived on Earth are estimated to be extinct . Estimates on the number of Earth 's current species range from 10 million to 14 million , of which about 1.2 million have been documented and over 86 percent have not yet been described . More recently , in May 2016 , scientists reported that 1 trillion species are estimated to be on Earth currently with only one-thousandth of one percent described . The total amount of related DNA base pairs on Earth is estimated at 5.0 x 1037 and weighs 50 billion tonnes . In comparison , the total mass of the biosphere has been estimated to be as much as 4 TtC ( trillion tons of carbon ) . In July 2016 , scientists reported identifying a set of 355 genes from the Last Universal Common Ancestor ( LUCA ) of all organisms living on Earth . The age of the Earth is about 4.54 billion years old . The earliest undisputed evidence of life on Earth dates at least from 3.5 billion years ago , during the Eoarchean Era after a geological crust started to solidify following the earlier molten Hadean Eon . There are microbial mat fossils found in 3.48 billion-year-old sandstone discovered in Western Australia . Other early physical evidence of a biogenic substance is graphite in 3.7 billion-year-old meta-sedimentary rocks discovered in Western Greenland . More recently , in 2015 , `` remains of biotic life '' were found in 4.1 billion-year-old rocks in Western Australia . According to one of the researchers , `` If life arose relatively quickly on Earth . . then it could be common in the universe . '' Since life began on Earth , five major mass extinctions and several minor events have led to large and sudden drops in biodiversity . The Phanerozoic eon ( the last 540 million years ) marked a rapid growth in biodiversity via the Cambrian explosion -- a period during which the majority of multicellular phyla first appeared . The next 400 million years included repeated , massive biodiversity losses classified as mass extinction events . In the Carboniferous , rainforest collapse led to a great loss of plant and animal life . The Permian -- Triassic extinction event , 251 million years ago , was the worst ; vertebrate recovery took 30 million years . The most recent , the Cretaceous -- Paleogene extinction event , occurred 65 million years ago and has often attracted more attention than others because it resulted in the extinction of the dinosaurs . The period since the emergence of humans has displayed an ongoing biodiversity reduction and an accompanying loss of genetic diversity . Named the Holocene extinction , the reduction is caused primarily by human impacts , particularly habitat destruction . Conversely , biodiversity impacts human health in a number of ways , both positively and negatively . The United Nations designated 2011 -- 2020 as the United Nations Decade on Biodiversity . |
880 | The_Daily_Caller | The peer-reviewed study by two scientists and a veteran statistician looked at the global average temperature datasets[…] | The Daily Caller The Daily Caller is an American news and opinion website based in Washington , D.C. . It was founded by Tucker Carlson , a libertarian conservative political pundit , and Neil Patel , former adviser to former Vice President Dick Cheney . The site 's coverage includes politics , business , world news , entertainment , sports , education , technology , outdoors , and energy . The Daily Caller launched on January 11 , 2010 as a more politically conservative news and commentary outlet and alternative to the liberal The Huffington Post , similarly featuring sections in broad range of subjects beyond politics . By late 2012 , The New York Times reported that the site had quadrupled its page view and total audience and had become profitable without ever buying an advertisement for itself . Vince Coglianese has served as the publication 's editor-in-chief since Carlson left to focus on his television program Tucker Carlson Tonight . |
1276 | Attribution_of_recent_climate_change | "Typically, in such an attribution study, scientists will use sets of climate models — one set including the factors that drive human global warming and the other including purely "natural" factors — and see if an event like the one in question is more likely to occur in the first set of models. | 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 ) . |
1435 | Ecology | An area of coastal ecosystems larger than New York City is destroyed every year, removing an important buffer from extreme weather for coastal communities and releasing carbon dioxide into the atmosphere. | Ecology Ecology ( from οἶκος , `` house '' , or `` environment '' ; - λογία , `` study of '' ) is the scientific analysis and study of interactions among organisms and their environment . It is an interdisciplinary field that includes biology , geography , and Earth science . Ecology includes the study of interactions that organisms have with each other , other organisms , and with abiotic components of their environment . Topics of interest to ecologists include the diversity , distribution , amount ( biomass ) , and number ( population ) of particular organisms , as well as cooperation and competition between organisms , both within and among ecosystems . Ecosystems are composed of dynamically interacting parts including organisms , the communities they make up , and the non-living components of their environment . Ecosystem processes , such as primary production , pedogenesis , nutrient cycling , and various niche construction activities , regulate the flux of energy and matter through an environment . These processes are sustained by organisms with specific life history traits , and the variety of organisms is called biodiversity . Biodiversity , which refers to the varieties of species , genes , and ecosystems , enhances certain ecosystem services . Ecology is not synonymous with environment , environmentalism , natural history , or environmental science . It is closely related to evolutionary biology , genetics , and ethology . An important focus for ecologists is to improve the understanding of how biodiversity affects ecological function . Ecologists seek to explain : Life processes , interactions , and adaptations The movement of materials and energy through living communities The successional development of ecosystems The abundance and distribution of organisms and biodiversity in the context of the environment . There are many practical applications of ecology in conservation biology , wetland management , natural resource management ( agroecology , agriculture , forestry , agroforestry , fisheries ) , city planning ( urban ecology ) , community health , economics , basic and applied science , and human social interaction ( human ecology ) . For example , the Circles of Sustainability approach treats ecology as more than the environment ` out there ' . It is not treated as separate from humans . Organisms ( including humans ) and resources compose ecosystems which , in turn , maintain biophysical feedback mechanisms that moderate processes acting on living ( biotic ) and non-living ( abiotic ) components of the planet . Ecosystems sustain life-supporting functions and produce natural capital like biomass production ( food , fuel , fiber , and medicine ) , the regulation of climate , global biogeochemical cycles , water filtration , soil formation , erosion control , flood protection , and many other natural features of scientific , historical , economic , or intrinsic value . The word `` ecology '' ( '' Ökologie '' ) was coined in 1866 by the German scientist Ernst Haeckel ( 1834 -- 1919 ) . Ecological thought is derivative of established currents in philosophy , particularly from ethics and politics . Ancient Greek philosophers such as Hippocrates and Aristotle laid the foundations of ecology in their studies on natural history . Modern ecology became a much more rigorous science in the late 19th century . Evolutionary concepts relating to adaptation and natural selection became the cornerstones of modern ecological theory . |
620 | Climate_change_in_the_United_States | Temperatures in the Southwest increased by nearly two degrees Fahrenheit (one degree Celsius) from 1901 to 2010, and some climate models forecast a total rise of six degrees or more by the end of this century. | Climate change in the United States Because of global warming , there has been concern in the United States and internationally , that the country should reduce total greenhouse gas which is relatively high per capita . In 2012 , the United States experienced its warmest year on record . , the thirteen warmest years for the entire planet have all occurred since 1998 , transcending those from 1880 . From 1950 to 2009 , the American government 's surface temperature record shows an increase by 1 F-change , approximately . Global warming has caused many changes in the U.S. . According to a 2009 statement by the National Oceanic and Atmospheric Administration ( NOAA ) , trends include lake and river ice melting earlier in the spring , plants blooming earlier , multiple animal species shifting their habitat ranges northward , and reductions in the size of glaciers . Predicting future climate changes are fraught with difficulty . Some research has warned against possible problems due to American climate changes such as the spread of invasive species and possibilities of floods as well as droughts . Changes in climate in the regions of the United States appear significant . Drought conditions appear to be worsening in the southwest while improving in the northeast for example . President Barack Obama committed in the December 2009 Copenhagen Climate Change Summit to reduce carbon dioxide emissions in the range of 17 % below 2005 levels by 2020 , 42 % below 2005 levels by 2030 , and 83 % below 2005 levels by 2050 . In an address towards the U.S. Congress in June 2013 , Obama detailed a specific action plan to achieve the 17 % carbon emissions cut from 2005 by 2020 . He included such measures as shifting from coal-based power generation to solar and natural gas production . Climate change is seen as a national security threat to the United States . In 2015 , according to The New York Times and others , oil companies knew that burning oil and gas could cause global warming since the 1970s but , nonetheless , funded deniers for years . 2016 was an historic year for billion-dollar weather and climate disasters in U.S. |
2361 | Intergovernmental_Panel_on_Climate_Change | "Unquestionably, the U.N. Intergovernmental Panel on Climate Change (IPCC) was formed to build the scientific case for humanity being the primary cause of global warming. | 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 . |
2951 | Solar_irradiance | The two most cited composites are PMOD and ACRIM. | Solar irradiance Solar irradiance is the power per unit area received from the Sun in the form of electromagnetic radiation in the wavelength range of the measuring instrument . Irradiance may be measured in space or at the Earth 's surface after atmospheric absorption and scattering . It is measured perpendicular to the incoming sunlight . Total solar irradiance ( TSI ) , is a measure of the solar power over all wavelengths per unit area incident on the Earth 's upper atmosphere . The solar constant is a conventional measure of mean TSI at a distance of one astronomical Unit ( AU ) . Irradiance is a function of distance from the Sun , the solar cycle , and cross-cycle changes . Irradiance on Earth is also measured perpendicular to the incoming sunlight . Insolation is the power received on Earth per unit area on a horizontal surface . It depends on the height of the Sun above the horizon . |
575 | Instrumental_temperature_record | While an isolated heatwave can be put down as an anomaly, the scale of this phenomenon points to global warming as the culprit, scientists said. | Instrumental temperature record The instrumental temperature record provides the temperature of Earth 's climate system from the historical network of in situ measurements of surface air temperatures and ocean surface temperatures . Data are collected at thousands of meteorological stations , buoys and ships around the globe . The longest-running temperature record is the Central England temperature data series , that starts in 1659 . The longest-running quasi-global record starts in 1850 . In recent decades more extensive sampling of ocean temperatures at various depths have begun allowing estimates of ocean heat content but these do not form part of the global surface temperature datasets . |
2895 | GRACE_and_GRACE-FO | The latest measurements involve the use of satellite gravimetry, estimating the mass of terrain beneath by detecting slight changes in gravity as a satellite passes overhead. | 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. |
143 | Greenhouse_gas | Recent modelling data suggests the climate is considerably more sensitive to carbon emissions than previously believed | 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 . |
1532 | Intergovernmental_Panel_on_Climate_Change | Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. | 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 . |
2662 | Ice_age | "...there is the contention by Wolfgang Knorr of the Department of Earth Sciences at the University of Bristol in England that carbon dioxide levels in the atmosphere are about where they were 160 years ago." (as quoted by Ken Ward Jr.) | Ice age An ice age is a period of long-term reduction in the temperature of Earth 's surface and atmosphere , resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers . Within a long-term ice age , individual pulses of cold climate are termed `` glacial periods '' ( or alternatively `` glacials '' or `` glaciations '' or colloquially as `` ice age '' ) , and intermittent warm periods are called `` interglacials '' . In the terminology of glaciology , ice age implies the presence of extensive ice sheets in both northern and southern hemispheres . By this definition , we are in an interglacial period -- the Holocene -- of the ice age . The ice age began 2.6 million years ago at the start of the Pleistocene epoch , because the Greenland , Arctic , and Antarctic ice sheets still exist . |
1640 | Global_warming | Recent studies agree that recent global temperatures are unprecedented in the last 1000 years. | 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 . |
583 | Bahrain | But despite [the Gulf Stream], the summer of 2018 looks set to be one of the hottest on record. | Bahrain Bahrain ( -LSB- bɑːˈreɪn -RSB- البحرين ) , officially the Kingdom of Bahrain , is a small Arab monarchy in the Arabian Gulf . It is an island country consisting of a small archipelago centered around Bahrain Island , situated between the Qatar peninsula and the north eastern coast of Saudi Arabia , to which it is connected by the 25 km King Fahd Causeway . Bahrain 's population is 1,234,571 ( c. 2010 ) , including 666,172 non-nationals . It is 780 km2 in size , making it the third smallest nation in Asia after the Maldives and Singapore . Bahrain is the site of the ancient Dilmun civilisation . It has been famed since antiquity for its pearl fisheries , which were considered the best in the world into the 19th century . Bahrain was one of the earliest areas to convert to Islam ( 628 ) . Following a period of Arab rule , Bahrain was occupied by the Portuguese in 1521 , who in turn were expelled in 1602 by Shah Abbas I of the Safavid dynasty under the Persian Empire . In 1783 , the Bani Utbah clan captured Bahrain from Nasr Al-Madhkur and it has since been ruled by the Al Khalifa royal family , with Ahmed al Fateh as Bahrain 's first hakim . In the late 1800s , following successive treaties with the British , Bahrain became a protectorate of the United Kingdom . In 1971 , Bahrain declared independence . Formerly an emirate , Bahrain was declared a Kingdom in 2002 . In 2011 , the country experienced protests inspired by the regional Arab Spring . Bahrain had the first post-oil economy in the Arabian Gulf . Since the late 20th century , Bahrain has invested in the banking and tourism sectors . Many large financial institutions have a presence in Manama , the country 's capital . Bahrain has a high Human Development Index and was recognised by the World Bank as a high income economy . |
1331 | Tide_pool | More than half of the 44 studies selected for publication found that raised levels of CO2 had little or no impact on marine life, including crabs, limpets, sea urchins and sponges | Tide pool Tide pools , or rock pools , are rocky pools on the sea shore which are filled with seawater . Many of these pools exist as separate pools only at low tide . Many tide pools are habitats of especially adaptable animals that have engaged the attention of naturalists and marine biologists , as well as philosophical essayists : John Steinbeck wrote in The Log from the Sea of Cortez , `` It is advisable to look from the tide pool to the stars and then back to the tide pool . '' |
2117 | Sea_level_rise | Global sea level data shows that sea level rise has been increasing since 1880 while future sea level rise predictions are based on physics, not statistics. | 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 . |
678 | Livestock | In the process, the cows will emit much greenhouse gas, and they will consume far more calories in beans than they will yield in meat, meaning far more clearcutting of forests to farm cattle feed than would be necessary if the beans above were simply eaten by people." | Livestock Livestock are domesticated animals raised in an agricultural setting to produce commodities such as food , fiber , and labor . The term is often used to refer solely to those raised for food , and sometimes only farmed ruminants , such as cattle and goats . In recent years , some organizations have also raised livestock to promote the survival of rare breeds . The breeding , maintenance , and slaughter of these animals , known as animal husbandry , is a component of modern agriculture that has been practiced in many cultures since humanity 's transition to farming from hunter-gatherer lifestyles . Animal husbandry practices have varied widely across cultures and time periods . Originally , livestock were not confined by fences or enclosures , but these practices have largely shifted to intensive animal farming , sometimes referred to as `` factory farming '' . These practices increase yield of the various commercial outputs , but have led to increased concerns about animal welfare and environmental impact . Livestock production continues to play a major economic and cultural role in numerous rural communities . |
2894 | Climate_change_(general_concept) | "Rapid loss of ice-mass from the glaciers of Greenland and Antarctica are cited as proof positive of global warming's onslaught. | Climate change (general concept) Climate variability includes all the variations in the climate that last longer than individual weather events, whereas the term climate change only refers to those variations that persist for a longer period of time, typically decades or more. In the time since the industrial revolution the climate has increasingly been affected by human activities that are causing global warming and climate change.The climate system receives nearly all of its energy from the sun. The climate system also radiates energy to outer space. The balance of incoming and outgoing energy, and the passage of the energy through the climate system, determines Earth\'s energy budget. When the incoming energy is greater than the outgoing energy, earth\'s energy budget is positive and the climate system is warming. If more energy goes out, the energy budget is negative and earth experiences cooling.\nThe energy moving through Earth\'s climate system finds expression in weather, varying on geographic scales and time. Long-term averages and variability of weather in a region constitute the region\'s climate. Such changes can be the result of "internal variability", when natural processes inherent to the various parts of the climate system alter the distribution of energy. Examples include variability in ocean basins such as the Pacific decadal oscillation and Atlantic multidecadal oscillation. Climate variability can also result from external forcing, when events outside of the climate system\'s components nonetheless produce changes within the system. Examples include changes in solar output and volcanism.\nClimate variability has consequences for sea level changes, plant life, and mass extinctions; it also affects human societies. |
1387 | Effects_of_global_warming_on_humans | […] Killing 30 million bats every year in response to dubious claims that global warming might once in a great while kill 100,000 bats makes no sense." | 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 . |
556 | Pago_Pago | The April low temperatures here are now about 6 degrees Fahrenheit warmer than they used to be. | Pago Pago Pago Pago ( -LSB- ˈpɑːŋɡoʊˈpɑːŋɡoʊ -RSB- Samoan : -LSB- ˈpaŋo ˈpaŋo -RSB- ) is the territorial capital of American Samoa . It is on the main island of American Samoa , Tutuila . The territory is served by Pago Pago International Airport at Tafuna , some 8 miles south west of Pago Pago . Tourism , entertainment , food , and tuna canning are its main industries . The area commonly referred to as Pago Pago consists of a string of villages , each with its own village council , on the shores of Pago Pago Harbor . One of the villages is itself named Pago Pago , and in 2010 had a population of 3,656 . Pago Pago may refer to the village , to the bay area or to American Samoa as a whole . The constituent villages are , in order , Utulei , Fagatogo , Malaloa , Pago Pago , Satala and Atu'u . Fagatogo is the area referred to as Town and was the seat of government until a new Executive Office Building was opened in Utulei . In Fagatoto is the Fono ( Legislature ) , the Police Department , the Port of Pago Pago , many shops and hotels . |
2255 | Earth | And since the last ice age ended almost exactly 11,500 years ago…" (Ice Age Now) | 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 . |
1077 | Antarctica | Antarctic ice fluctuates wildly year to year, and the link to man-made global warming there is not clear, NASA ice expert Walt Meier said. | 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 . |
1279 | Hubble_Space_Telescope | "Earlier this month, NASA scientists provided a visualization of a startling climate change trend — the Earth is getting greener, as viewed from space, especially in its rapidly warming northern regions. | Hubble Space Telescope The Hubble Space Telescope ( HST ) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation . Although not the first space telescope , Hubble is one of the largest and most versatile , and is well known as both a vital research tool and a public relations boon for astronomy . The HST is named after the astronomer Edwin Hubble , and is one of NASA 's Great Observatories , along with the Compton Gamma Ray Observatory , the Chandra X-ray Observatory , and the Spitzer Space Telescope . With a 2.4 m mirror , Hubble 's four main instruments observe in the near ultraviolet , visible , and near infrared spectra . Hubble 's orbit outside the distortion of Earth 's atmosphere allows it to take extremely high-resolution images , with substantially lower background light than ground-based telescopes . Hubble has recorded some of the most detailed visible light images ever , allowing a deep view into space and time . Many Hubble observations have led to breakthroughs in astrophysics , such as accurately determining the rate of expansion of the universe . The HST was built by the United States space agency NASA , with contributions from the European Space Agency . The Space Telescope Science Institute ( STScI ) selects Hubble 's targets and processes the resulting data , while the Goddard Space Flight Center controls the spacecraft . Space telescopes were proposed as early as 1923 . Hubble was funded in the 1970s , with a proposed launch in 1983 , but the project was beset by technical delays , budget problems , and the Challenger disaster ( 1986 ) . When finally launched in 1990 , Hubble 's main mirror was found to have been ground incorrectly , compromising the telescope 's capabilities . The optics were corrected to their intended quality by a servicing mission in 1993 . Hubble is the only telescope designed to be serviced in space by astronauts . After launch by in 1990 , five subsequent Space Shuttle missions repaired , upgraded , and replaced systems on the telescope , including all five of the main instruments . The fifth mission was canceled on safety grounds following the Columbia disaster ( 2003 ) . However , after spirited public discussion , NASA administrator Mike Griffin approved the fifth servicing mission , completed in 2009 . The telescope is operating , and could last until 2030 -- 2040 . Its scientific successor , the James Webb Space Telescope ( JWST ) , is scheduled for launch in 2018 . |
1910 | Solar_panel | It takes as much energy to make a solar panel as it likely generates in its entire life. | Solar panel Solar panels absorb the sunlight as a source of energy to generate electricity or heat . A photovoltaic ( PV ) module is a packaged , connect assembly of typically 6x10 photovoltaic solar cells . Photovoltaic modules constitute the photovoltaic array of a photovoltaic system that generates and supplies solar electricity in commercial and residential applications . Each module is rated by its DC output power under standard test conditions ( STC ) , and typically ranges from 100 to 365 Watts ( W ) . The efficiency of a module determines the area of a module given the same rated output an 8 % efficient 230 W module will have twice the area of a 16 % efficient 230 W module . There are a few commercially available solar modules that exceed efficiency of 22 % and reportedly also exceeding 24 % . A single solar module can produce only a limited amount of power ; most installations contain multiple modules . A photovoltaic system typically includes an array of photovoltaic modules , an inverter , a battery pack for storage , interconnection wiring , and optionally a solar tracking mechanism . The most common application of solar panels is solar water heating systems . The price of solar power has continued to fall so that in many countries it is cheaper than ordinary fossil fuel electricity from the grid ( there is `` grid parity '' ) . |
637 | Sea | By 2100 the seas will rise another 6 inches or so—a far cry from Al Gore's alarming numbers | Sea A sea is a large body of salt water that is surrounded in whole or in part by land . More broadly , `` the sea '' is the interconnected system of Earth 's salty , oceanic waters -- considered as one global ocean or as several principal oceanic divisions . The sea moderates Earth 's climate and has important roles in the water cycle , carbon cycle , and nitrogen cycle . Although the sea has been traveled and explored since prehistory , the modern scientific study of the sea -- oceanography -- dates broadly to the British Challenger expedition of the 1870s . The sea is conventionally divided into up to five large oceanic sections -- including the International Hydrographic Organization 's four named oceans ( the Atlantic , Pacific , Indian , and Arctic ) and the Southern Ocean ; smaller , second-order sections , such as the Mediterranean , are known as seas . Owing to the present state of continental drift , the Northern Hemisphere is now fairly equally divided between land and sea ( a ratio of about 2:3 ) but the South is overwhelmingly oceanic ( 1:4.7 ) . Salinity in the open ocean is generally in a narrow band around 3.5 % by mass , although this can vary in more landlocked waters , near the mouths of large rivers , or at great depths . About 85 % of the solids in the open sea are sodium chloride . Deep-sea currents are produced by differences in salinity and temperature . Surface currents are formed by the friction of waves produced by the wind and by tides , the changes in local sea level produced by the gravity of the Moon and Sun . The direction of all of these is governed by surface and submarine land masses and by the rotation of the Earth ( the Coriolis effect ) . Former changes in sea levels have left continental shelves , shallow areas in the sea close to land . These nutrient-rich waters teem with life , which provide humans with substantial supplies of food -- mainly fish , but also shellfish , mammals , and seaweed -- which are both harvested in the wild and farmed . The most diverse areas surround great tropical coral reefs . Whaling in the deep sea was once common but whales ' dwindling numbers prompted international conservation efforts and finally a moratorium on most commercial hunting . Oceanography has established that not all life is restricted to the sunlit surface waters : even under enormous depths and pressures , nutrients streaming from hydrothermal vents support their own unique ecosystem . Life may have started there and aquatic microbial mats are generally credited with the oxygenation of Earth 's atmosphere ; both plants and animals first evolved in the sea . The sea is an essential aspect of human trade , travel , mineral extraction , and power generation . This has also made it essential to warfare and left major cities exposed to earthquakes and volcanoes from nearby faults ; powerful tsunami waves ; and hurricanes , typhoons , and cyclones produced in the tropics . This importance and duality has affected human culture , from early sea gods to the epic poetry of Homer to the changes induced by the Columbian Exchange , from burial at sea to Basho 's haikus to hyperrealist marine art , and inspiring music ranging from the shanties in The Complaynt of Scotland to Rimsky-Korsakov 's `` The Sea and Sinbad 's Ship '' to A-mei 's `` Listen to the Sea '' . It is the scene of leisure activities including swimming , diving , surfing , and sailing . However , population growth , industrialization , and intensive farming have all contributed to present-day marine pollution . Atmospheric carbon dioxide is being absorbed in increasing amounts , lowering its pH in a process known as ocean acidification . The shared nature of the sea has made overfishing an increasing problem . |
473 | Pacific_Ocean | La Niñas, on the other hand, feature cooler than average waters in the Pacific | Pacific Ocean The Pacific Ocean is the largest and deepest of the Earth 's oceanic divisions . It extends from the Arctic Ocean in the north to the Southern Ocean ( or , depending on definition , to Antarctica ) in the south and is bounded by Asia and Australia in the west and the Americas in the east . At 63,800,000 sqmi in area , this largest division of the World Ocean -- and , in turn , the hydrosphere -- covers about 46 % of the Earth 's water surface and about one-third of its total surface area , making it larger than all of the Earth 's land area combined . The equator subdivides it into the North Pacific Ocean and South Pacific Ocean , with two exceptions : the Galápagos and Gilbert Islands , while straddling the equator , are deemed wholly within the South Pacific . The Mariana Trench in the western North Pacific is the deepest point in the world , reaching a depth of 35797 ft. Both the center of the Water Hemisphere and the Western Hemisphere are in the Pacific Ocean . Though the peoples of Asia and Oceania have traveled the Pacific Ocean since prehistoric times , the eastern Pacific was first sighted by Europeans in the early 16th century when Spanish explorer Vasco Núñez de Balboa crossed the Isthmus of Panama in 1513 and discovered the great `` southern sea '' which he named Mar del Sur ( in Spanish ) . The ocean 's current name was coined by Portuguese explorer Ferdinand Magellan during the Spanish circumnavigation of the world in 1521 , as he encountered favorable winds on reaching the ocean . He called it Mar Pacífico , which in both Portuguese and Spanish means `` peaceful sea '' . |
2910 | Sensor-based_sorting | The authors seem to have jumped right into statistical analysis without proposing a physical mechanism that works. | Sensor-based sorting Sensor-based sorting , is an umbrella term for all applications where particles are singularly detected by a sensor technique and rejected by an amplified mechanical , hydraulic or pneumatic process . The technique is generally applied in the three industries mining , recycling and food processing and used in the particle size range between 0.5 and . Since sensor-based sorting is a single particle separation technology , the throughput is proportional to the average particle size and weight fed onto the machine . |
1937 | Climate_change_and_ecosystems | Not only is there no scientific evidence that CO2 is a pollutant, higher CO2 concentrations actually help ecosystems support more plant and animal life. | Climate change and ecosystems This article is about climate change and ecosystems . |
3090 | Deforestation | A generous estimate of the energy generated by satellites is around 1 million times too small to cause global warming. | 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 . |
800 | Intergovernmental_Panel_on_Climate_Change | The report, published in the journal Nature Geoscience on September 18, acknowledges that most of the models of warming trends failed to predict the 'slowdown' in warming post-2000, resulting in less pronounced warming than predicted and thus more room in the CO2 'emissions budget' for the coming decades. | 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 . |
1327 | Orlando,_Florida | Migration patterns show people heading for warm states like Texas and Florida, not snowy Minnesota and Michigan." | Orlando, Florida Orlando ( -LSB- ɔrˈlændoʊ -RSB- ) is a city in the U.S. state of Florida and the county seat of Orange County . Located in Central Florida , it is the center of the Orlando metropolitan area , which had a population of 2,387,138 , according to U.S. Census Bureau figures released in March 2016 , making it the 24th-largest metropolitan area in the United States , the sixth-largest metropolitan area in the Southern United States , and the third-largest metropolitan area in Florida . As of 2015 , Orlando had an estimated city-proper population of 2,270,934 , making it the 73rd-largest city in the United States , the fourth-largest city in Florida , and the state 's largest inland city . The City of Orlando is nicknamed `` The City Beautiful , '' and its symbol is the fountain at Lake Eola . Orlando is also known as `` The Theme Park Capital of the World '' and in 2014 its tourist attractions and events drew more than 62 million visitors . The Orlando International Airport ( MCO ) is the thirteenth-busiest airport in the United States and the 29th-busiest in the world . Buddy Dyer is Orlando 's mayor . As one of the world 's most visited tourist destinations , Orlando 's famous attractions form the backbone of its tourism industry : Walt Disney World , located approximately 21 mi southwest of Downtown Orlando in Bay Lake , opened by the Walt Disney Company in 1971 ; the Universal Orlando Resort , opened in 1999 as a major expansion of Universal Studios Florida . With the exception of Walt Disney World , most major attractions are located along International Drive . The city is also one of the busiest American cities for conferences and conventions ; the Orange County Convention Center is the second-largest convention facility in the United States . Like other major cities in the Sun Belt , Orlando grew rapidly during the 1980s and into the first decade of the 21st century , mostly due to the success of Walt Disney World , which was opened on October 1 , 1971 . Orlando is home to the University of Central Florida , which is the largest university campus in the United States in terms of enrollment . In 2010 , Orlando was listed as a `` Gamma − '' level of world-city in the World Cities Study Group 's inventory . Orlando ranks as the fourth-most popular American city based on where people want to live according to a 2009 Pew Research Center study . |
1562 | Global_warming | Methane is the only cause of climate change. | 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 . |
2275 | Hurricane_Sandy | […] Constant 24-7 media coverage of every significant storm worldwide just makes it seem that way." | Hurricane Sandy Hurricane Sandy ( unofficially referred to as `` Superstorm Sandy '' ) was the deadliest and most destructive hurricane of the 2012 Atlantic hurricane season , and the second-costliest hurricane in United States history . Classified as the eighteenth named storm , tenth hurricane and second major hurricane of the year , Sandy was a Category 3 storm at its peak intensity when it made landfall in Cuba . While it was a Category 2 storm off the coast of the Northeastern United States , the storm became the largest Atlantic hurricane on record ( as measured by diameter , with winds spanning 1100 mi ) . Estimates as of 2015 assessed damage to have been about $ 75 billion ( 2012 USD ) , a total surpassed only by Hurricane Katrina . At least 233 people were killed along the path of the storm in eight countries . Sandy developed from a tropical wave in the western Caribbean Sea on October 22 , quickly strengthened , and was upgraded to Tropical Storm Sandy six hours later . Sandy moved slowly northward toward the Greater Antilles and gradually intensified . On October 24 , Sandy became a hurricane , made landfall near Kingston , Jamaica , re-emerged a few hours later into the Caribbean Sea and strengthened into a Category 2 hurricane . On October 25 , Sandy hit Cuba as a Category 3 hurricane , then weakened to a Category 1 hurricane . Early on October 26 , Sandy moved through the Bahamas . On October 27 , Sandy briefly weakened to a tropical storm and then restrengthened to a Category 1 hurricane . Early on October 29 , Sandy curved west-northwest ( the `` left turn '' or `` left hook '' ) and then moved ashore near Brigantine , New Jersey , just to the northeast of Atlantic City , as a post-tropical cyclone with hurricane-force winds . In Jamaica , winds left 70 % of residents without electricity , blew roofs off buildings , killed one , and caused about $ 100 million ( 2012 USD ) in damage . Sandy 's outer bands brought flooding to Haiti , killing at least 54 , causing food shortages , and leaving about 200,000 homeless ; the hurricane also caused two deaths in the Dominican Republic . In Puerto Rico , one man was swept away by a swollen river . In Cuba , there was extensive coastal flooding and wind damage inland , destroying some 15,000 homes , killing 11 , and causing $ 2 billion ( 2012 USD ) in damage . Sandy caused two deaths and damage estimated at $ 700 million ( 2012 USD ) in The Bahamas . In the United States , Hurricane Sandy affected 24 states , including the entire eastern seaboard from Florida to Maine and west across the Appalachian Mountains to Michigan and Wisconsin , with particularly severe damage in New Jersey and New York . Its storm surge hit New York City on October 29 , flooding streets , tunnels and subway lines and cutting power in and around the city . Damage in the United States amounted to $ 71.4 billion ( 2013 USD ) . In Canada , two were killed in Ontario and an estimated $ 100 million ( 2012 CAD ) in damage was caused throughout Ontario and Quebec . |
2114 | Peer_review | Peer review process was corrupted | Peer review Peer review is the evaluation of work by one or more people of similar competence to the producers of the work ( peers ) . It constitutes a form of self-regulation by qualified members of a profession within the relevant field . Peer review methods are employed to maintain standards of quality , improve performance , and provide credibility . In academia , scholarly peer review is often used to determine an academic paper 's suitability for publication . Peer review can be categorized by the type of activity and by the field or profession in which the activity occurs , e.g. , medical peer review . |
2048 | Greenhouse_gas | CO2 is a greenhouse gas but is clearly subordinate to water vapour and other more significant factors determining global climate. | 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 . |
2853 | Ozone_layer | The Ozone Layer stops UV radiation from entering our atmosphere. | Ozone layer The ozone layer or ozone shield is a region of Earth 's stratosphere that absorbs most of the Sun 's ultraviolet ( UV ) radiation . It contains high concentrations of ozone ( O3 ) in relation to other parts of the atmosphere , although still small in relation to other gases in the stratosphere . The ozone layer contains less than 10 parts per million of ozone , while the average ozone concentration in Earth 's atmosphere as a whole is about 0.3 parts per million . The ozone layer is mainly found in the lower portion of the stratosphere , from approximately 20 to above Earth , although its thickness varies seasonally and geographically . The ozone layer was discovered in 1913 by the French physicists Charles Fabry and Henri Buisson . Measurements of the sun showed that the radiation sent out from its surface and reaching the ground on Earth is usually consistent with the spectrum of a black body with a temperature in the range of 5,500 -- 6,000 K ( 5,227 to 5,727 ° C ) , except that there was no radiation below a wavelength of about 310 nm at the ultraviolet end of the spectrum . It was deduced that the missing radiation was being absorbed by something in the atmosphere . Eventually the spectrum of the missing radiation was matched to only one known chemical , ozone . Its properties were explored in detail by the British meteorologist G. M. B. Dobson , who developed a simple spectrophotometer ( the Dobsonmeter ) that could be used to measure stratospheric ozone from the ground . Between 1928 and 1958 , Dobson established a worldwide network of ozone monitoring stations , which continue to operate to this day . The `` Dobson unit '' , a convenient measure of the amount of ozone overhead , is named in his honor . The ozone layer absorbs 97 to 99 percent of the Sun 's medium-frequency ultraviolet light ( from about 200 nm to 315 nm wavelength ) , which otherwise would potentially damage exposed life forms near the surface . The United Nations General Assembly has designated September 16 as the International Day for the Preservation of the Ozone Layer . Venus also has a thin ozone layer at an altitude of 100 kilometers from the planet 's surface . |
44 | Scientific_consensus_on_climate_change | Human-produced carbon might be one of the factors [of climate change], but there's simply no evidence that it is a significant one. | 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. |
2260 | Carbon_dioxide | The current debate on the connection between CO2 emissions and climate change has largely overlooked an independent and equally serious problem, the increasing acidity of our oceans. | 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 . |
2836 | Post-glacial_rebound | Thanks to a rapid rebound in recent months, global sea ice levels now equal those seen 29 years ago, when the year 1979 also drew to a close. | Post-glacial rebound Post-glacial rebound ( also called either isostatic rebound or crustal rebound ) is the rise of land masses that were depressed by the huge weight of ice sheets during the last glacial period , through a process known as isostatic depression . Post-glacial rebound and isostatic depression are different parts of a process known as either glacial isostasy , glacial isostatic adjustment , or glacioisostasy . Glacioisostasy is the solid Earth deformation associated with changes in ice mass distribution . The most obvious and direct effects of post-glacial rebound are readily apparent in parts of Northern Eurasia , Northern America , Patagonia , and Antarctica . However , through processes known as ocean siphoning and continental levering , the effects of post-glacial rebound on sea level are felt globally far from the locations of current and former ice sheets . |
3044 | Maldives | Thousands of coral atolls have "drowned" in the past when they were unable to grow fast enough to maintain a presence at sea level | Maldives The Maldives ( -LSB- ˈmɒldiːvz -RSB- , -LSB- ˈmɔːldiːvz -RSB- , -LSB- ˈmɔːldaɪvz -RSB- or -LSB- ˈmældaɪvz -RSB- ) , officially the Republic of Maldives ( ދިވެހިރާއްޖޭގެ ޖުމްހޫރިއްޔާ , Dhivehi Raa ` jeyge Jumhooriyya ) , is a South Asian island country , located in the Indian Ocean , situated in the Arabian Sea . It lies southwest of India and Sri Lanka . The chain of twenty-six atolls stretches from Ihavandhippolhu Atoll in the north to the Addu City in the south . Comprising a territory spanning roughly 298 km2 , the Maldives is one of the world 's most geographically dispersed countries , as well as the smallest Asian country by both land area and population , with a little over 393,500 inhabitants . Malé is the capital and most populated city , traditionally called the `` King 's Island '' for its central location . The Maldives archipelago is located atop the Chagos-Maldives-Laccadive Ridge , a vast submarine mountain range in the Indian Ocean , which also forms a terrestrial ecoregion , together with the Chagos and the Lakshadweep . With an average ground-level elevation of 1.5 m above sea level , it is the world 's lowest country , with even its highest natural point being the lowest in the world , at 2.4 m. Due to the subsequent risks posed by rising sea-levels , the government pledged in 2009 to make the Maldives a carbon-neutral country by 2019 . The Maldives have been historically and culturally linked to the Indian subcontinent since the fourth century BCE . The Maldivian archipelago was Islamised in the 12th century and consolidated as a sultanate , developing strong commercial and cultural ties with Asia and Africa . From the mid 16th-century , the region came under the increasing influence of European colonial powers , with the Maldives becoming a British protectorate in 1887 . Independence from the United Kingdom was achieved in 1965 and a presidential republic was established in 1968 with an elected People 's Majlis . The ensuing decades have been characterised by political instability , efforts at democratic reform , and environmental challenges posed by climate change . The Maldives is a founding member of the South Asian Association for Regional Cooperation ( SAARC ) . It is also a member of the United Nations , the Organization of Islamic Cooperation and the Non Aligned Movement . The World Bank classifies the Maldives as having an upper middle income economy . Fishing has historically been the dominant economic activity , and remains the largest sector by far , followed by the rapidly growing tourism industry . Along with Sri Lanka , it is one of only two South Asian countries rated `` high '' on the Human Development Index ( HDI ) , with its per capita income the highest among SAARC nations . The Maldives was a Commonwealth republic from July 1982 until its withdrawal from the Commonwealth in October 2016 in protest of international criticism of its records in relation to corruption and human rights . |
413 | Greenhouse_gas | However, since 1998, little warming has occurred while carbon dioxide emissions continue to increase. | 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 . |
1862 | Carbon_dioxide | Carbon dioxide is not "a primary contributor to the global warming that we see." | 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 . |
1219 | Sea_level_rise | Global warming is driving major melting on the surface of Greenland's glaciers and is speeding up their travel into the sea." | 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 . |
272 | Sea_level_rise | The melting ice has led to global sea level rise of around eight inches since reliable record keeping began in 1880. | 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 . |
1634 | Retreat_of_glaciers_since_1850 | Satellites measure Antarctica losing land ice at an accelerating rate. | 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 . |
1116 | Year_Without_a_Summer | Severe 'snowmageddon' winters are now strongly linked to soaring polar temperatures, say researchers, with deadly summer heatwaves and torrential floods also probably linked. | Year Without a Summer The year 1816 is known as the Year Without a Summer ( also the Poverty Year , the Summer that Never Was , Year There Was No Summer , and Eighteen Hundred and Froze to Death ) because of severe climate abnormalities that caused average global temperatures to decrease by 0.4 -- 0.7 ° C ( 0.7 -- 1.3 ° F ) . This resulted in major food shortages across the Northern Hemisphere . Evidence suggests that the anomaly was predominantly a volcanic winter event caused by the massive 1815 eruption of Mount Tambora in the Dutch East Indies ( the largest eruption in at least 1,300 years after the extreme weather events of 535 -- 536 ) , perhaps plus the 1814 eruption of Mayon in the Philippines . The Earth had already been in a centuries-long period of global cooling that started in the 14th century . Known today as the Little Ice Age , it had already caused considerable agricultural distress in Europe . The Little Ice Age 's existing cooling was aggravated by the eruption of Tambora , which occurred during its concluding decades . |
503 | Polar_vortex | "During the sunless winter, a heatwave raised concerns that the polar vortex may be eroding. | Polar vortex A polar vortex is an upper level low-pressure area lying near the Earth 's pole . There are two polar vortices in the Earth 's atmosphere , which overlie the North , and South Poles . Each polar vortex is a persistent , large-scale , low pressure zone that rotates counter-clockwise at the North Pole ( called a cyclone ) , and clockwise at the South Pole . The bases of the two polar vortices are located in the middle and upper troposphere and extend into the stratosphere . Beneath that lies a large mass of cold , dense arctic air . The vortices weaken and strengthen from year to year . When the vortex of the arctic is strong it is well defined , there is a single vortex and the arctic air is well contained ; when weaker , which it generally is , it will break into two or more vortices ; when very weak , the flow of arctic air becomes more disorganized and masses of cold arctic air can push equatorward , bringing with it a rapid and sharp temperature drop . The interface between the cold dry air mass of the pole and the warm moist air mass further south defines the location of the polar front . The polar front is centered , roughly at 60 ° latitude . A polar vortex strengthens in the winter and weakens in the summer due to its dependence on the temperature difference between the equator and the poles . The vortices span less than 1,000 kilometers ( 620 miles ) in diameter within which they rotate counter-clockwise in the Northern Hemisphere , and in a clockwise fashion in the Southern Hemisphere . As with other cyclones , their rotation is driven by the Coriolis effect . When the polar vortex is strong , there is a single vortex with a jet stream that is `` well constrained '' near the polar front . When the northern vortex weakens , it separates into two or more vortices , the strongest of which are near Baffin Island , Canada and the other over northeast Siberia . The Antarctic vortex of the Southern Hemisphere is a single low pressure zone that is found near the edge of the Ross ice shelf near 160 west longitude . When the polar vortex is strong , the mid-latitude Westerlies ( winds at the surface level between 30 ° and 60 ° latitude from the west ) increase in strength and are persistent . When the polar vortex is weak , high pressure zones of the mid latitudes may push poleward , moving the polar vortex , jet stream , and polar front equatorward . The jet stream is seen to `` buckle '' and deviate south . This rapidly brings cold dry air into contact with the warm , moist air of the mid latitudes , resulting in a rapid and dramatic change of weather known as a `` cold snap '' . Ozone depletion occurs within the polar vortices -- particularly over the Southern Hemisphere -- reaching a maximum depletion in the spring . |
1827 | Climate_change_(general_concept) | Rob Portman voted for the bipartisan bill to affirm climate change is real, humans significantly contribute to it and it needs to be addressed. | Climate change (general concept) Climate variability includes all the variations in the climate that last longer than individual weather events, whereas the term climate change only refers to those variations that persist for a longer period of time, typically decades or more. In the time since the industrial revolution the climate has increasingly been affected by human activities that are causing global warming and climate change.The climate system receives nearly all of its energy from the sun. The climate system also radiates energy to outer space. The balance of incoming and outgoing energy, and the passage of the energy through the climate system, determines Earth\'s energy budget. When the incoming energy is greater than the outgoing energy, earth\'s energy budget is positive and the climate system is warming. If more energy goes out, the energy budget is negative and earth experiences cooling.\nThe energy moving through Earth\'s climate system finds expression in weather, varying on geographic scales and time. Long-term averages and variability of weather in a region constitute the region\'s climate. Such changes can be the result of "internal variability", when natural processes inherent to the various parts of the climate system alter the distribution of energy. Examples include variability in ocean basins such as the Pacific decadal oscillation and Atlantic multidecadal oscillation. Climate variability can also result from external forcing, when events outside of the climate system\'s components nonetheless produce changes within the system. Examples include changes in solar output and volcanism.\nClimate variability has consequences for sea level changes, plant life, and mass extinctions; it also affects human societies. |
442 | Instrumental_temperature_record | There is no empirical evidence that increasing greenhouse gases are the primary cause of Global Warming | Instrumental temperature record The instrumental temperature record provides the temperature of Earth 's climate system from the historical network of in situ measurements of surface air temperatures and ocean surface temperatures . Data are collected at thousands of meteorological stations , buoys and ships around the globe . The longest-running temperature record is the Central England temperature data series , that starts in 1659 . The longest-running quasi-global record starts in 1850 . In recent decades more extensive sampling of ocean temperatures at various depths have begun allowing estimates of ocean heat content but these do not form part of the global surface temperature datasets . |
558 | Vine | Species that have a lot of plasticity tend to be generalists. | Vine A vine ( Latin vīnea `` grapevine '' , `` vineyard '' , from vīnum `` wine '' ) in the narrowest sense is the grapevine ( Vitis ) , but more generally it can refer to any plant with a growth habit of trailing or scandent ( that is , climbing ) stems , lianas or runners . The word also can refer to such stems or runners themselves , for instance when used in wicker work . In the United Kingdom , the term `` vine '' applies almost exclusively to the grapevine . The term `` climber '' is used for all climbing plants . |
2083 | Conspiracy_theory | Climategate CRU emails suggest conspiracy | Conspiracy theory A conspiracy theory is an explanation of an event or situation that invokes a conspiracy without warrant , generally one involving an illegal or harmful act carried out by government or other powerful actors . Conspiracy theories often produce hypotheses that contradict the prevailing understanding of history or simple facts . The term is a derogatory one . According to the political scientist Michael Barkun , conspiracy theories rely on the view that the universe is governed by design , and embody three principles : nothing happens by accident , nothing is as it seems , and everything is connected . Another common feature is that conspiracy theories evolve to incorporate whatever evidence exists against them , so that they become , as Barkun writes , a closed system that is unfalsifiable , and therefore `` a matter of faith rather than proof '' . |
2036 | Scientific_consensus_on_climate_change | The global surface mean temperature-change data no longer have any scientific value and are nothing more than a propaganda tool to the public. | 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. |
1638 | Global_catastrophic_risk | Worry about global warming impacts in the next 100 years, not an ice age in over 10,000 years. | Global catastrophic risk A global catastrophic risk is a hypothetical future event that has the potential to damage human well-being on a global scale . Some events could cripple or destroy modern civilization . Any event that could cause human extinction is known as an existential risk . Potential global catastrophic risks include anthropogenic risks ( technology risks , governance risks ) and natural or external risks . Examples of technology risks are hostile artificial intelligence , biotechnology risks , or nanotechnology weapons . Insufficient global governance creates risks in the social and political domain ( potentially leading to a global war with or without a nuclear holocaust , bioterrorism using genetically modified organisms , cyberterrorism destroying critical infrastructures like the electrical grid , or the failure to manage a natural pandemic ) as well as problems and risks in the domain of earth system governance ( with risks resulting from global warming , environmental degradation , mineral resource exhaustion , fossil energy exhaustion , or famine as a result of non-equitable resource distribution , human overpopulation , crop failures and non-sustainable agriculture ) . Examples for non-anthropogenic risks are an asteroid impact event , a supervolcanic eruption , a lethal gamma-ray burst , a geomagnetic storm destroying all electronic equipment , natural long-term climate change , or extraterrestrial life impacting life on Earth . |
1354 | El_Niño | Often the compensatory cooling, known as La Niña, is larger than the El Niño warming." | El Niño El Niño -LSB- ɛl_ˈniːnjoʊ -RSB- ( -LSB- el ˈniɲo -RSB- ) is the warm phase of the El Niño Southern Oscillation ( commonly called ENSO ) and is associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific ( between approximately the International Date Line and 120 ° W ) , including off the Pacific coast of South America . El Niño Southern Oscillation refers to the cycle of warm and cold temperatures , as measured by sea surface temperature , SST , of the tropical central and eastern Pacific Ocean . El Niño is accompanied by high air pressure in the western Pacific and low air pressure in the eastern Pacific . The cool phase of ENSO is called `` La Niña '' with SST in the eastern Pacific below average and air pressures high in the eastern and low in western Pacific . The ENSO cycle , both El Niño and La Niña , cause global changes of both temperatures and rainfall . Developing countries that are dependent upon agriculture and fishing , particularly those bordering the Pacific Ocean , are usually most affected . In American Spanish , the capitalized term `` El Niño '' refers to `` the little boy '' , so named because the pool of warm water in the Pacific near South America is often at its warmest around Christmas . The original name , `` El Niño de Navidad '' , traces its origin centuries back to Peruvian fisherman , who named the weather phenomenon in reference to the newborn Christ . `` La Niña '' , chosen as the ` opposite ' of El Niño , literally translates to `` the little girl '' . |
2052 | PH | Nor is there any evidence that levels as high as 7,000 ppm of CO2 did or could cause ocean acidity. | PH In chemistry , pH ( -LSB- piːˈeɪtʃ -RSB- ) ( potential of hydrogen ) is a numeric scale used to specify the acidity or basicity of an aqueous solution . It is approximately the negative of the base 10 logarithm of the molar concentration , measured in units of moles per liter , of hydrogen ions . More precisely it is the negative of the logarithm to base 10 of the activity of the hydrogen ion . Solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic . Pure water is neutral , at pH 7 , being neither an acid nor a base . Contrary to popular belief , the pH value can be less than 0 or greater than 14 for very strong acids and bases respectively . pH measurements are important in agronomy , medicine , biology , chemistry , agriculture , forestry , food science , environmental science , oceanography , civil engineering , chemical engineering , nutrition , water treatment and water purification , as well as many other applications . The pH scale is traceable to a set of standard solutions whose pH is established by international agreement . Primary pH standard values are determined using a concentration cell with transference , by measuring the potential difference between a hydrogen electrode and a standard electrode such as the silver chloride electrode . The pH of aqueous solutions can be measured with a glass electrode and a pH meter , or an indicator . |
839 | Climate_change_mitigation | "Even if we meet the Paris goals of two degrees warming, cities like Karachi and Kolkata will become close to uninhabitable, annually encountering deadly heat waves like those that crippled them in 2015. | 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 . |
2286 | Sun | By regulating the Earth's cloud cover, the Sun can turn the temperature up and down. ... | 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 . |
2796 | Greenhouse_effect | Had he used the currently accepted value of approximately 3°C warming for a doubling of atmospheric CO2, Hansen would have correctly projected the ensuing global warming. | 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 . |
1230 | United_States | On the Pacific Coast, a climate pattern that had pushed billions of gallons of water toward Asia is now ending, so that in coming decades the sea is likely to rise quickly off states like Oregon and California. | 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 . |
2994 | Mauna_Loa_Observatory | 'Mauna Loa has been producing a readout which supports Manning's predetermined goal by showing steady growth in atmospheric CO2 concentrations since 1959. | Mauna Loa Observatory The Mauna Loa Observatory ( MLO ) is an atmospheric baseline station on Mauna Loa , on the island of Hawaii . |
1626 | Global_warming | Climate reacts to whatever forces it to change at the time; humans are now the dominant forcing. | 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 . |
1441 | 2015_United_Nations_Climate_Change_Conference | 195 countries signed the 2015 Paris Agreement, agreeing to limit global warming and adapt to climate change, partly by protecting nature. | 2015 United Nations Climate Change Conference The 2015 United Nations Climate Change Conference , COP 21 or CMP 11 was held in Paris , France , from 30 November to 12 December 2015 . It was the 21st yearly session of the Conference of the Parties ( COP ) to the 1992 United Nations Framework Convention on Climate Change ( UNFCCC ) and the 11th session of the Conference of the Parties ( CMP ) to the 1997 Kyoto Protocol . The conference negotiated the Paris Agreement , a global agreement on the reduction of climate change , the text of which represented a consensus of the representatives of the 196 parties attending it . The agreement will enter into force when joined by at least 55 countries which together represent at least 55 percent of global greenhouse emissions . On 22 April 2016 ( Earth Day ) , 174 countries signed the agreement in New York , and began adopting it within their own legal systems ( through ratification , acceptance , approval , or accession ) . According to the organizing committee at the outset of the talks , the expected key result was an agreement to set a goal of limiting global warming to less than 2 degrees Celsius ( ° C ) compared to pre-industrial levels . The agreement calls for zero net anthropogenic greenhouse gas emissions to be reached during the second half of the 21st century . In the adopted version of the Paris Agreement , the parties will also `` pursue efforts to '' limit the temperature increase to 1.5 ° C . The 1.5 ° C goal will require zero emissions sometime between 2030 and 2050 , according to some scientists . Prior to the conference , 146 national climate panels publicly presented draft national climate contributions ( called `` Intended Nationally Determined Contributions '' , INDCs ) . These suggested commitments were estimated to limit global warming to 2.7 degrees Celsius by 2100 . For example , the EU suggested INDC is a commitment to a 40 percent reduction in emissions by 2030 compared to 1990 . The agreement establishes a `` global stocktake '' which revisits the national goals to `` update and enhance '' them every five years beginning 2023 . However , no detailed timetable or country-specific goals for emissions were incorporated into the Paris Agreement -- as opposed to the previous Kyoto Protocol . A number of meetings took place in preparation for COP21 , including the Bonn Climate Change Conference , 19 to 23 October 2015 , which produced a draft agreement . |
2564 | Shutdown_of_thermohaline_circulation | This small warming is likely a result of the natural alterations in global ocean currents which are driven by ocean salinity variations. | Shutdown of thermohaline circulation A shutdown or slowdown of the thermohaline circulation is an effect of global warming on a major ocean circulation . Data from 2010 NASA suggested that the Atlantic Meridional Overturning Circulation has not slowed down , but may have actually sped up slightly in the recent past . However , this has been superseded by a 2015 study that suggests ` that the Gulf Stream has weakened by 15-20 % ' |
565 | Physics | In looking at Earth's past, scientists can predict what the future will look like | Physics Physics ( from -LSB- φυσική , phusikḗ ( epistḗmē ) , knowledge of nature -RSB- , from φύσις phúsis `` nature '' ) is the natural science that involves the study of matter and its motion and behavior through space and time , along with related concepts such as energy and force . One of the most fundamental scientific disciplines , the main goal of physics is to understand how the universe behaves . Physics is one of the oldest academic disciplines , perhaps the oldest through its inclusion of astronomy . Over the last two millennia , physics was a part of natural philosophy along with chemistry , biology , and certain branches of mathematics , but during the scientific revolution in the 17th century , the natural sciences emerged as unique research programs in their own right . Physics intersects with many interdisciplinary areas of research , such as biophysics and quantum chemistry , and the boundaries of physics are not rigidly defined . New ideas in physics often explain the fundamental mechanisms of other sciences while opening new avenues of research in areas such as mathematics and philosophy . Physics also makes significant contributions through advances in new technologies that arise from theoretical breakthroughs . For example , advances in the understanding of electromagnetism or nuclear physics led directly to the development of new products that have dramatically transformed modern-day society , such as television , computers , domestic appliances , and nuclear weapons ; advances in thermodynamics led to the development of industrialization , and advances in mechanics inspired the development of calculus . The United Nations named 2005 the World Year of Physics . |
642 | Nuclear_holocaust | Some experts think we're on track to hit 550 ppm by the end of the century, which would cause average global temperatures to rise by 6 degrees Celsius | Nuclear holocaust A nuclear holocaust or nuclear apocalypse is a theoretical scenario involving widespread destruction and radioactive fallout causing the collapse of civilization , through the use of nuclear weapons . Under such a scenario , some of the Earth is made uninhabitable by nuclear warfare in future world wars . Besides the obvious direct destruction of cities by nuclear blasts , the potential aftermath of a nuclear war could involve firestorms , a nuclear winter , widespread radiation sickness from fallout , and/or the temporary loss of much modern technology due to electromagnetic pulses . Some scientists , such as Alan Robock , have speculated that a thermonuclear war could result in the end of modern civilization on Earth , in part due to a long-lasting nuclear winter . In one model , temperatures following a full thermonuclear war fall for several years by 7 to 8 degrees Celsius on average . The accuracy of such models are often the subject of partisan dispute . Early Cold War-era studies suggested that billions of humans would nonetheless survive the immediate effects of nuclear blasts and radiation following a global thermonuclear war . Some scholars argue that nuclear war could indirectly contribute to human extinction via secondary effects , including environmental consequences , societal breakdown , and economic collapse . Additionally , it has been argued that even a relatively small-scale nuclear exchange between India and Pakistan involving 100 Hiroshima yield weapons , could cause a nuclear winter and kill more than a billion people . Since 1947 , the Doomsday Clock of the Bulletin of the Atomic Scientists has visualized how close the world is from a nuclear war . The threat of a nuclear holocaust plays an important role in the popular perception of nuclear weapons . It features in the security concept of mutually assured destruction ( MAD ) and is a common scenario in survivalism . Nuclear holocaust is a common feature in literature and film , especially in speculative genres such as science fiction , dystopian and post-apocalyptic fiction . |
2428 | Carbon_dioxide | It was the post war industrialization that caused the rapid rise in global CO2 emissions, but by 1945 when this began, the Earth was already in a cooling phase that started around 1942 and continued until 1975. | 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 . |
1985 | North_Pole | The North Pole is melting "a bit" but the South Pole is getting bigger. | North Pole The North Pole , also known as the Geographic North Pole or Terrestrial North Pole , is ( subject to the caveats explained below ) defined as the point in the Northern Hemisphere where the Earth 's axis of rotation meets its surface . The North Pole is the northernmost point on the Earth , lying diametrically opposite the South Pole . It defines geodetic latitude 90 ° North , as well as the direction of true north . At the North Pole all directions point south ; all lines of longitude converge there , so its longitude can be defined as any degree value . Along tight latitude circles , counterclockwise is east and clockwise is west . The North Pole is at the center of the Northern Hemisphere . While the South Pole lies on a continental land mass , the North Pole is located in the middle of the Arctic Ocean amid waters that are almost permanently covered with constantly shifting sea ice . This makes it impractical to construct a permanent station at the North Pole ( unlike the South Pole ) . However , the Soviet Union , and later Russia , constructed a number of manned drifting stations on a generally annual basis since 1937 , some of which have passed over or very close to the Pole . Since 2002 , the Russians have also annually established a base , Barneo , close to the Pole . This operates for a few weeks during early spring . Studies in the 2000s predicted that the North Pole may become seasonally ice-free because of Arctic ice shrinkage , with timescales varying from 2016 to the late 21st century or later . The sea depth at the North Pole has been measured at 4261 m by the Russian Mir submersible in 2007 and at 4,087 m ( 13,410 ft ) by USS Nautilus in 1958 . The nearest land is usually said to be Kaffeklubben Island , off the northern coast of Greenland about 700 km away , though some perhaps non-permanent gravel banks lie slightly closer . The nearest permanently inhabited place is Alert in the Qikiqtaaluk Region , Nunavut , Canada , which is located 817 km from the Pole . |
2134 | Tuvalu | Tuvalu sea level isn't rising | Tuvalu Tuvalu ( -LSB- tᵿˈvɑːlu -RSB- or -LSB- ˈtuːvəˌluː -RSB- ) , formerly known as the Ellice Islands , is a Polynesian island nation located in the Pacific Ocean , about midway between Hawaii and Australia , lying east-northeast of the Santa Cruz Islands ( belonging to the Solomons ) , southeast of Nauru , south of Kiribati , west of Tokelau , northwest of Samoa and Wallis and Futuna and north of Fiji . It comprises three reef islands and six true atolls spread out between the latitude of 5 ° to 10 ° south and longitude of 176 ° to 180 ° , west of the International Date Line . Tuvalu has a population of 10,640 ( 2012 census ) . The total land area of the islands of Tuvalu is 26 km2 . The first inhabitants of Tuvalu were Polynesians . The pattern of settlement that is believed to have occurred is that the Polynesians spread out from Samoa and Tonga into the Tuvaluan atolls , with Tuvalu providing a stepping stone to migration into the Polynesian Outlier communities in Melanesia and Micronesia . In 1568 , Spanish navigator Álvaro de Mendaña was the first European to sail through the archipelago , sighting the island of Nui during his expedition in search of Terra Australis . In 1819 the island of Funafuti was named Ellice 's Island ; the name Ellice was applied to all nine islands after the work of English hydrographer Alexander George Findlay . The islands came under Britain 's sphere of influence in the late 19th century , when each of the Ellice Islands was declared a British Protectorate by Captain Gibson of between 9 and 16 October 1892 . The Ellice Islands were administered as British protectorate by a Resident Commissioner from 1892 to 1916 as part of the British Western Pacific Territories ( BWPT ) , and then as part of the Gilbert and Ellice Islands colony from 1916 to 1974 . A referendum was held in December 1974 to determine whether the Gilbert Islands and Ellice Islands should each have their own administration . As a consequence of the referendum , the Gilbert and Ellice Islands colony ceased to exist on 1 January 1976 and the separate British colonies of Kiribati and Tuvalu came into existence . Tuvalu became fully independent within the Commonwealth on 1 October 1978 . On 5 September 2000 Tuvalu became the 189th member of the United Nations . |
1460 | Sea_level_rise | Global sea level rose about 8 inches in the last century. | 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 . |
169 | Ocean_acidification | They can now model how likely a specific event would be to occur under historical conditions, compared to the record temperatures we're experiencing. | Ocean acidification Ocean acidification is the ongoing decrease in the pH of the Earth 's oceans , caused by the uptake of carbon dioxide from the atmosphere . Seawater is slightly basic ( meaning pH > 7 ) , and the process in question is a shift towards pH-neutral conditions rather than a transition to acidic conditions ( pH < 7 ) . Ocean alkalinity is not changed by the process , or may increase over long time periods due to carbonate dissolution . An estimated 30 -- 40 % of the carbon dioxide from human activity released into the atmosphere dissolves into oceans , rivers and lakes . To achieve chemical equilibrium , some of it reacts with the water to form carbonic acid . Some of these extra carbonic acid molecules react with a water molecule to give a bicarbonate ion and a hydronium ion , thus increasing ocean acidity ( H + ion concentration ) . Between 1751 and 1996 surface ocean pH is estimated to have decreased from approximately 8.25 to 8.14 , representing an increase of almost 35 % in H + ion concentration in the world 's oceans . Earth System Models project that within the last decade ocean acidity exceeded historical analogues and in combination with other ocean biogeochemical changes could undermine the functioning of marine ecosystems and disrupt the provision of many goods and services associated with the ocean . Increasing acidity is thought to have a range of potentially harmful consequences for marine organisms , such as depressing metabolic rates and immune responses in some organisms , and causing coral bleaching . By increasing the presence of free hydrogen ions , each molecule of carbonic acid that forms in the oceans ultimately results in the conversion of two carbonate ions into bicarbonate ions . This net decrease in the amount of carbonate ions available makes it more difficult for marine calcifying organisms , such as coral and some plankton , to form biogenic calcium carbonate , and such structures become vulnerable to dissolution . Ongoing acidification of the oceans threatens food chains connected with the oceans . As members of the InterAcademy Panel , 105 science academies have issued a statement on ocean acidification recommending that by 2050 , global emissions be reduced by at least 50 % compared to the 1990 level . While ongoing ocean acidification is anthropogenic in origin , it has occurred previously in Earth 's history . The most notable example is the Paleocene-Eocene Thermal Maximum ( PETM ) , which occurred approximately 56 million years ago . For reasons that are currently uncertain , massive amounts of carbon entered the ocean and atmosphere , and led to the dissolution of carbonate sediments in all ocean basins . Ocean acidification has been called the `` evil twin of global warming '' and `` the other problem '' . |
2387 | Climate_change_in_the_Arctic | The Greenland ice sheet is at least 400,000 years old and warming was not global when Europeans settled in Greeland 1,000 years ago | 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 . |
2501 | Sea_surface_temperature | The human fingerprint in global warming is evident in multiple lines of empirical evidence - in satellite measurements of outgoing infrared radiation, in surface measurements of downward infrared radiation, in the cooling stratosphere and other metrics. | 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 . |
87 | Global_warming | NOAA has adjusted past temperatures to look colder than they were and recent temperatures to look warmer than they were. | 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 . |
1859 | Net_metering | Big rooftop solar's plan forces Nevada families who don't have solar panels to pay higher power bills to subsidize rooftop solar. | Net metering Net metering ( or net energy metering , NEM ) allows consumers who generate some or all of their own electricity to use that electricity anytime , instead of when it is generated . This is particularly important with wind and solar , which are non-dispatchable . Monthly net metering allows consumers to use solar power generated during the day at night , or wind from a windy day later in the month . Annual net metering rolls over a net kilowatt credit to the following month , allowing solar power that was generated in July to be used in December , or wind power from March in August . Net metering policies can vary significantly by country and by state or province : if net metering is available , if and how long banked credits can be retained , and how much the credits are worth ( retail/wholesale ) . Most net metering laws involve monthly roll over of kWh credits , a small monthly connection fee , require monthly payment of deficits ( i.e. normal electric bill ) , and annual settlement of any residual credit . Unlike a feed-in tariff ( FIT ) , which requires two meters , net metering uses a single , bi-directional meter and can measure current flowing in two directions . Net metering can be implemented solely as an accounting procedure , and requires no special metering , or even any prior arrangement or notification . Net metering is an enabling policy designed to foster private investment in renewable energy . |
1708 | Climatic_Research_Unit_documents | The 'decline' refers to a decline in northern tree-rings, not global temperature, and is openly discussed in papers and the IPCC reports. | Climatic Research Unit documents Climatic Research Unit documents including thousands of e-mails and other computer files were stolen from a server at the Climatic Research Unit of the University of East Anglia in a hacking incident in November 2009 . The documents were redistributed first through several blogs of global warming skeptics , and allegations were made that they indicated misconduct by leading climate scientists . A series of investigations rejected these allegations , while concluding that CRU scientists should have been more open with distributing data and methods on request . Precisely six committees investigated the allegations and published reports , finding no evidence of fraud or scientific misconduct . The scientific consensus that global warming is occurring as a result of human activity remained unchanged by the end of the investigations . The incident occurred shortly before the opening December 2009 Copenhagen global climate summit . It has prompted general discussion about increasing the openness of scientific data ( though the majority of climate data have always been freely available ) . Scientists , scientific organisations , and government officials have stated that the incident does not affect the overall scientific case for climate change . Andrew Revkin reported in the New York Times that `` The evidence pointing to a growing human contribution to global warming is so widely accepted that the hacked material is unlikely to erode the overall argument . '' |
531 | Kilowatt_hour | When South Australians buy electricity at $14,200/MWh, they are paying the equivalent of $400 a litre for petrol. | Kilowatt hour The kilowatt-hour ( symbol kWh , kW ⋅ h or kW h ) is a derived unit of energy equal to 3.6 megajoules . If the energy is being transmitted or used at a constant rate ( power ) over a period of time , the total energy in kilowatt-hours is the power in kilowatts multiplied by the time in hours . The kilowatt-hour is commonly used as a billing unit for energy delivered to consumers by electric utilities . |
2402 | Scientific_consensus_on_climate_change | Although it has some very important and beneficial effects, CO2 meets the legal and encyclopedic definitions of a "pollutant", and human CO2 emissions pose a threat to public health and welfare. | 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. |
772 | Carbon_dioxide | Geologists say that humans are now pumping the gas into the air much faster than nature has ever done. | 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 . |
2365 | Intergovernmental_Panel_on_Climate_Change | Comparisons to the most recent data consistently finds that climate change is occurring more rapidly and intensely than indicated by IPCC predictions. | 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 . |
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