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880 | Hockey_stick_graph | The peer-reviewed study by two scientists and a veteran statistician looked at the global average temperature datasets[…] | Hockey stick graph Hockey stick graphs present the global or hemispherical mean temperature record of the past 500 to 2000 years as shown by quantitative climate reconstructions based on climate proxy records . These reconstructions have consistently shown a slow long term cooling trend changing into relatively rapid warming in the 20th century , with the instrumental temperature record by 2000 exceeding earlier temperatures . The term `` hockey stick graph '' was coined by the climatologist Jerry Mahlman , to describe the pattern shown by the ( MBH99 ) reconstruction , envisaging a graph that is relatively flat with a downward trend to 1900 as forming an ice hockey stick 's `` shaft '' followed by a sharp , steady increase corresponding to the `` blade '' portion . The reconstructions have featured in Intergovernmental Panel on Climate Change ( IPCC ) reports as evidence of global warming . Arguments over the reconstructions have been taken up by fossil fuel industry funded lobbying groups attempting to cast doubt on climate science . Paleoclimatology dates back to the 19th century , and the concept of examining varves in lake beds and tree rings to track local climatic changes was suggested in the 1930s . In the 1960s , Hubert Lamb generalised from historical documents and temperature records of central England to propose a Medieval Warm Period from around 900 to 1300 , followed by Little Ice Age . This was the basis of a `` schematic diagram '' featured in the IPCC First Assessment Report of 1990 beside cautions that the medieval warming might not have been global . The use of indicators to get quantitative estimates of the temperature record of past centuries was developed , and by the late 1990s a number of competing teams of climatologists found indications that recent warming was exceptional . introduced the `` Composite Plus Scaling '' ( CPS ) method used by most later large scale reconstructions . Their study was featured in the IPCC Second Assessment Report of 1995 . In 1998 Michael E. Mann , Raymond S. Bradley and Malcolm K. Hughes developed new statistical techniques to produce ( MBH98 ) , the first eigenvector-based climate field reconstruction ( CFR ) . This showed global patterns of annual surface temperature , and included a graph of average hemispheric temperatures back to 1400 with shading emphasising that uncertainties ( to two standard error limits ) were much greater in earlier centuries . independently produced a CPS reconstruction extending back for a thousand years , and ( MBH99 ) used the MBH98 methodology to extend their study back to 1000 . A version of the MBH99 graph was featured prominently in the 2001 IPCC Third Assessment Report ( TAR ) , which also drew on Jones et al. 1998 and three other reconstructions to support the conclusion that , in the Northern Hemisphere , the 1990s was likely to have been the warmest decade and 1998 the warmest year during the past 1,000 years . The graph became a focus of dispute for those opposed to the strengthening scientific consensus that late 20th century warmth was exceptional . In 2003 , as lobbying over the 1997 Kyoto Protocol intensified , a paper claiming greater medieval warmth was quickly dismissed by scientists in the Soon and Baliunas controversy . Later in 2003 , Stephen McIntyre and Ross McKitrick published disputing the data used in MBH98 paper . In 2004 Hans von Storch published criticism of the statistical techniques as tending to underplay variations in earlier parts of the graph , though this was disputed and he later accepted that the effect was very small . In 2005 McIntyre and McKitrick published criticisms of the principal components analysis methodology as used in MBH98 and MBH99 . Their analysis was subsequently disputed by published papers including and which pointed to errors in the McIntyre and McKitrick methodology . Political disputes led to the formation of a panel of scientists convened by the National Research Council , their North Report in 2006 supported Mann 's findings with some qualifications , including agreeing that there were some statistical failings but these had little effect on the result . More than two dozen reconstructions , using various statistical methods and combinations of proxy records , support the broad consensus shown in the original 1998 hockey-stick graph , with variations in how flat the pre-20th century `` shaft '' appears . The 2007 IPCC Fourth Assessment Report cited 14 reconstructions , 10 of which covered 1,000 years or longer , to support its strengthened conclusion that it was likely that Northern Hemisphere temperatures during the 20th century were the highest in at least the past 1,300 years . Further reconstructions , including Mann et al. 2008 and , have supported these general conclusions . |
1887 | Georgia_(U.S._state) | Florida ranks "45th out of 50 states'' for its regulatory climate for business. | Georgia (U.S. state) Georgia ( -LSB- ˈdʒɔrdʒə -RSB- ) is a state in the southeastern United States . It began as a British colony in 1733 , the last of the original Thirteen Colonies . Named after King George II of Great Britain , the Province of Georgia covered the area from South Carolina down to Spanish Florida and New France along La Louisiane , also bordering to the west towards the Mississippi River . Georgia was the fourth state to ratify the United States Constitution , on January 2 , 1788 . In 1802-1804 , western Georgia was split to the Mississippi Territory , which later split to form Alabama with part of former West Florida in 1819 . Georgia declared its secession from the Union on January 19 , 1861 , and was one of the original seven Confederate states . It was the last state to be restored to the Union , on July 15 , 1870 . Georgia is the 24th largest and the 8th most populous of the 50 United States . From 2007 to 2008 , 14 of Georgia 's counties ranked among the nation 's 100 fastest-growing , second only to Texas . Georgia is known as the Peach State and the Empire State of the South . Atlanta is the state 's capital , its most populous city , and has been named a global city . Georgia is bordered to the south by Florida , to the east by the Atlantic Ocean and South Carolina , to the west by Alabama , and to the north by Tennessee and North Carolina . The state 's northern part is in the Blue Ridge Mountains , part of the Appalachian Mountains system . The Piedmont extends through the central part of the state from the foothills of the Blue Ridge to the Fall Line , where the rivers cascade down in elevation to the coastal plain of the state 's southern part . Georgia 's highest point is Brasstown Bald at 4784 ft above sea level ; the lowest is the Atlantic Ocean . Georgia is the largest state entirely east of the Mississippi River in land area . |
1376 | Earth | Also, it is increasingly clear that the planet was significantly warmer than today several times during the past 10,000 years. | 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 . |
812 | Physical_impacts_of_climate_change | The human contribution can be up to 30 percent or so of the total rainfall coming out of the storm | Physical impacts of climate change This article is about the physical impacts of climate change . For some of these physical impacts , their effect on social and economic systems are also described . This article refers to reports produced by the IPCC . In their usage , `` climate change '' refers to a change in the state of the climate that can be identified by changes in the mean and/or variability of its properties , and that persists for extended periods , typically decades or longer ( IPCC , 2007d :30 ) . The climate change referred to may be due to natural causes and/or the result of human activity . |
784 | Climate_change_in_the_United_States | "Scientists have published strong evidence that the warming climate is making heat waves more frequent and intense. | 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. |
1180 | Global_warming | "It seems self-evident that rising sea levels will reduce land area. | 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 . |
2897 | GRACE_and_GRACE-FO | A new article in Nature Geoscience describes an innovative approach employed to derive ice-mass changes from GRACE data. | 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. |
2478 | Pale_Blue_Dot | (Kerr 2007) points out that the sunlight-reflecting haze that cools much of the planet seems to have thinned over the past decade or so. | Pale Blue Dot Pale Blue Dot is a photograph of planet Earth taken on February 14 , 1990 , by the Voyager 1 space probe from a record distance of about kilometers ( miles , 40.5 AU ) , as part of the Family Portrait series of images of the Solar System . In the photograph , Earth 's apparent size is less than a pixel ; the planet appears as a tiny dot against the vastness of space , among bands of sunlight scattered by the camera 's optics . Voyager 1 , which had completed its primary mission and was leaving the Solar System , was commanded by NASA to turn its camera around and take one last photograph of Earth across a great expanse of space , at the request of astronomer and author Carl Sagan . |
1665 | Carbon_dioxide | The effects of enhanced CO2 on terrestrial plants are variable and complex and dependent on numerous factors. | 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 . |
1492 | Sea_level_rise | Sea level rise due to climate change is not going to happen. | 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 . |
184 | Carbon_dioxide | It has never been shown that human emissions of carbon dioxide drive global warming. | 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 . |
1647 | Global_warming | Extreme weather events are being made more frequent and worse by global warming. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
2326 | Climate_change_in_the_Arctic | "In 2007, the Northern Hemisphere reached a record low in ice coverage and the Northwest Passage was opened. | 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 . |
1565 | Global_warming | They changed the name from 'global warming' to '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 . |
2765 | Quaternary_glaciation | "Earth's Albedo has risen in the past few years, and by doing reconstructions of the past albedo, it appears that there was a significant reduction in Earth's albedo leading up to a lull in 1997. | Quaternary glaciation The Quaternary glaciation , also known as the Pleistocene glaciation or the current ice age , is a series of glacial events separated by interglacial events during the Quaternary period from 2.58 Ma ( million years ago ) to present . During this period , ice sheets expanded , notably from out of Antarctica and Greenland , and fluctuating ice sheets occurred elsewhere ( for example , the Laurentide ice sheet ) . The major effects of the ice age are erosion and deposition of material over large parts of the continents , modification of river systems , creation of millions of lakes , changes in sea level , development of pluvial lakes far from the ice margins , isostatic adjustment of the crust , and abnormal winds . It affected oceans , flooding , and biological communities . The ice sheets themselves , by raising the albedo , affect a major feedback on climate cooling . |
558 | Effects_of_climate_change_on_terrestrial_animals | Species that have a lot of plasticity tend to be generalists. | Effects of climate change on terrestrial animals Climate change has had a significant direct effect on terrestrial animals , by being a major driver of the processes of speciation and extinction . The best known example of this is the Carboniferous Rainforest Collapse which occurred 350 million years ago . This event decimated amphibian populations and spurred on the evolution of reptiles . Climate change is a natural event that has occurred throughout history . However , with the recent increased emission of CO2 in the Earth 's atmosphere , abrupt climate change has occurred . It has been hypothesized that anthropogenic greenhouse gas forcing has significantly influenced global climate since about 8000 before present ( Van Hoof 2006 ) . Animals have had specific responses to climate change . Species respond to climate changes by migration , adaptation , or if neither of those occur , death . These migrations can sometimes follow an animal 's preferred temperature , elevation , soil , etc. , as said terrain moves due to climate change . Adaptation can be either genetic or phenological , and death can occur in a local population only ( extirpation ) or as an entire species , otherwise known as extinction . Climate changes is projected to affect individual organisms , populations , species distributions and ecosystem composition and function both directly ( ex . Increased temperatures and changes in precipitation ) and indirectly ( through climate changing the intensity and frequency of disturbances such as wildfires and severe storms ) ( IPCC 2002 ) . Every organism has a unique set of preferences or requirements , a niche and biodiversity has been tied to the diversity of animals ' niches . These can include or be affected by temperature , aridity , resource availability , habitat requirements , enemies , soil characteristics , competitors , and pollinators . Since the factors that compose a niche can be so complex and interconnected , the niches of many animals are bound to be affected by climate change ( Parmesan Yohe 2003 ) . One study done by Camille Parmesan and Gary Yohe from University of Texas , Austin shows the global fingerprint of climate change on natural systems . The results of their global analysis of 334 species were recorded to demonstrate the correlation of patterns consistent with global climate change of the 20th century . Using the IPCC 's ( Intergovernmental Panel on Climate Change ) ` levels of confidence ' , this study proved significant nonrandom behavioral changes due to global climate change with very high confidence ( > 95 ) . Furthermore , an accuracy of 74-91 % change in species has displayed predicted change for species in response to climate change . |
745 | Anoxic_event | The past shows that climate change is normal, that warmer times and more atmospheric carbon dioxide have driven biodiversity and that cold times kill." | Anoxic event Oceanic anoxic events or anoxic events ( anoxia conditions ) refer to intervals in the Earth 's past where portions of oceans become depleted in oxygen ( O2 ) at depths over a large geographic area . During some of these events , euxinia , waters that contained hydrogen sulfide , developed . Although anoxic events have not happened for millions of years , the geological record shows that they happened many times in the past . Anoxic events coincided with several mass extinctions and may have contributed to them . These mass extinctions include some that geobiologists use as time markers in biostratigraphic dating . Many geologists believe oceanic anoxic events are strongly linked to slowing of ocean circulation , climatic warming , and elevated levels of greenhouse gases . Researchers have proposed enhanced volcanism ( the release of CO2 ) as the `` central external trigger for euxinia '' . |
2560 | Last_Glacial_Period | In the 11,400 years since the end of the last Ice Age, sea level has risen at an average of 4 feet/century, though it is now rising much more slowly because very nearly all of the land-based ice that is at low enough latitudes and altitudes to melt has long since gone." | Last Glacial Period The Last Glacial Period (LGP) occurred from the end of the Eemian to the end of the Younger Dryas, encompassing the period c. 115,000 – c. 11,700 years ago. The LGP is part of a larger sequence of glacial and interglacial periods known as the Quaternary glaciation which started around 2,588,000 years ago and is ongoing. The definition of the Quaternary as beginning 2.58 million years ago is based on the formation of the Arctic ice cap. The Antarctic ice sheet began to form earlier, at about 34 Ma, in the mid-Cenozoic (Eocene–Oligocene extinction event). The term Late Cenozoic Ice Age is used to include this early phase.During this last glacial period there were alternating episodes of glacier advance and retreat. Within the last glacial period the Last Glacial Maximum was approximately 22,000 years ago. While the general pattern of global cooling and glacier advance was similar, local differences in the development of glacier advance and retreat make it difficult to compare the details from continent to continent (see picture of ice core data below for differences). Approximately 12,800 years ago, the Younger Dryas, the most recent glacial epoch, began, a coda to the preceding 100,000 year glacial period. Its end about 11,550 years ago marked the beginning of the Holocene, the current geological epoch. From the point of view of human archaeology, the last glacial period falls in the Paleolithic and early Mesolithic periods. When the glaciation event started, Homo sapiens were confined to lower latitudes and used tools comparable to those used by Neanderthals in western and central Eurasia and by Denisovans and Homo erectus in Asia. Near the end of the event, Homo sapiens migrated into Eurasia and Australia. Archaeological and genetic data suggest that the source populations of Paleolithic humans survived the last glacial period in sparsely wooded areas and dispersed through areas of high primary productivity while avoiding dense forest cover. |
2286 | Global_warming | By regulating the Earth's cloud cover, the Sun can turn the temperature up and down. ... | 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 . |
1173 | Renewable_energy | […]until we develop a practical, cost-competitive alternative to fossil fuels, it is unlikely that renewable energy will ever make up more than 15-20% of global energy requirements. | Renewable energy Renewable energy is energy that is collected from renewable resources , which are naturally replenished on a human timescale , such as sunlight , wind , rain , tides , waves , and geothermal heat . Renewable energy often provides energy in four important areas : electricity generation , air and water heating/cooling , transportation , and rural ( off-grid ) energy services . Based on REN21 's 2016 report , renewables contributed 19.2 % to humans ' global energy consumption and 23.7 % to their generation of electricity in 2014 and 2015 , respectively . This energy consumption is divided as 8.9 % coming from traditional biomass , 4.2 % as heat energy ( modern biomass , geothermal and solar heat ) , 3.9 % hydro electricity and 2.2 % is electricity from wind , solar , geothermal , and biomass . Worldwide investments in renewable technologies amounted to more than US$ 286 billion in 2015 , with countries like China and the United States heavily investing in wind , hydro , solar and biofuels . Globally , there are an estimated 7.7 million jobs associated with the renewable energy industries , with solar photovoltaics being the largest renewable employer . As of 2015 worldwide , more than half of all new electricity capacity installed was renewable . Renewable energy resources exist over wide geographical areas , in contrast to other energy sources , which are concentrated in a limited number of countries . Rapid deployment of renewable energy and energy efficiency is resulting in significant energy security , climate change mitigation , and economic benefits . The results of a recent review of the literature concluded that as greenhouse gas ( GHG ) emitters begin to be held liable for damages resulting from GHG emissions resulting in climate change , a high value for liability mitigation would provide powerful incentives for deployment of renewable energy technologies . In international public opinion surveys there is strong support for promoting renewable sources such as solar power and wind power . At the national level , at least 30 nations around the world already have renewable energy contributing more than 20 percent of energy supply . National renewable energy markets are projected to continue to grow strongly in the coming decade and beyond . Some places and at least two countries , Iceland and Norway generate all their electricity using renewable energy already , and many other countries have the set a goal to reach 100 % renewable energy in the future . For example , in Denmark the government decided to switch the total energy supply ( electricity , mobility and heating/cooling ) to 100 % renewable energy by 2050 . While many renewable energy projects are large-scale , renewable technologies are also suited to rural and remote areas and developing countries , where energy is often crucial in human development . United Nations ' Secretary-General Ban Ki-moon has said that renewable energy has the ability to lift the poorest nations to new levels of prosperity . As most of renewables provide electricity , renewable energy deployment is often applied in conjunction with further electrification , which has several benefits : Electricity can be converted to heat ( where necessary generating higher temperatures than fossil fuels ) , can be converted into mechanical energy with high efficiency and is clean at the point of consumption . In addition to that electrification with renewable energy is much more efficient and therefore leads to a significant reduction in primary energy requirements , because most renewables do n't have a steam cycle with high losses ( fossil power plants usually have losses of 40 to 65 % ) . Renewable energy systems are rapidly becoming more efficient and cheaper . Their share of total energy consumption is increasing . Growth in consumption of coal and oil could end by 2020 due to increased uptake of renewables and natural gas . |
2826 | Lake_Tahoe | A drop of volcanic activity in the early 20th century may have had a warming effect. | Lake Tahoe Lake Tahoe ( -LSB- ˈtɑːhoʊ -RSB- ) is a large freshwater lake in the Sierra Nevada of the United States . Lying at 6225 ft , it straddles the border between California and Nevada , west of Carson City . Lake Tahoe is the largest alpine lake in North America , and at 122160280 acre.ft trails only the five Great Lakes as the largest by volume in the United States . Its depth is 1645 ft , making it the second deepest in the United States after Crater Lake in Oregon ( 1945 ft ) . The lake was formed about 2 million years ago as part of the Lake Tahoe Basin , with the modern extent being shaped during the ice ages . It is known for the clarity of its water and the panorama of surrounding mountains on all sides . The area surrounding the lake is also referred to as Lake Tahoe , or simply Tahoe . More than 75 % of the lake 's watershed is national forest land , comprising the Lake Tahoe Basin Management Unit of the United States Forest Service . Lake Tahoe is a major tourist attraction in both Nevada and California . It is home to winter sports , summer outdoor recreation , and scenery enjoyed throughout the year . Snow and ski resorts are a significant part of the area 's economy and reputation . The Nevada side also offers large casinos , with highways providing year-round access to the entire area . |
1920 | Arctic_sea_ice_decline | Melting of Arctic sea ice and polar icecaps is not occurring at unnatural rates and does not constitute evidence of a human impact on the climate. | Arctic sea ice decline Arctic sea ice decline is the sea ice loss observed in recent decades in the Arctic Ocean . The Intergovernmental Panel on Climate Change ( IPCC ) Fourth Assessment Report states that greenhouse gas forcing is largely , but not wholly , responsible for the decline in Arctic sea ice extent . A study from 2011 suggested that internal variability enhanced the greenhouse gas forced sea ice decline over the last decades . A study from 2007 found the decline to be `` faster than forecasted '' by model simulations . The IPCC Fifth Assessment Report concluded with high confidence that sea ice continues to decrease in extent , and that there is robust evidence for the downward trend in Arctic summer sea ice extent since 1979 . It has been established that the region is at its warmest for at least 40,000 years and the Arctic-wide melt season has lengthened at a rate of 5 days per decade ( from 1979 to 2013 ) , dominated by a later autumn freezeup . Sea ice changes have been identified as a mechanism for polar amplification . |
2978 | Troposphere | The lower temperatures at this "coldest point" have caused global water vapor levels to drop, even as carbon levels rise. | Troposphere The troposphere is the lowest portion of Earth 's atmosphere , and is also where nearly all weather takes place . It contains approximately 75 % of the atmosphere 's mass and 99 % of the total mass of water vapor and aerosols . The average depths of the troposphere are 20 km in the tropics , 17 km in the mid latitudes , and 7 km in the polar regions in winter . The lowest part of the troposphere , where friction with the Earth 's surface influences air flow , is the planetary boundary layer . This layer is typically a few hundred meters to 2 km deep depending on the landform and time of day . Atop the troposphere is the tropopause , which is the border between the troposphere and stratosphere . The tropopause is an inversion layer , where the air temperature ceases to decrease with height and remains constant through its thickness . The word troposphere derives from the for `` turn , turn toward , trope '' and '' - sphere '' ( as in , the Earth ) , reflecting the fact that rotational turbulent mixing plays an important role in the troposphere 's structure and behaviour . Most of the phenomena associated with day-to-day weather occur in the troposphere . |
2608 | Methane | And their wind and manure emit more than one third of emissions of another, methane, which warms the world 20 times faster than carbon dioxide. | Methane Methane ( -LSB- ˈmɛθeɪn -RSB- or -LSB- ˈmiːθeɪn -RSB- ) is a chemical compound with the chemical formula ( one atom of carbon and four atoms of hydrogen ) . It is a group 14 hydride and the simplest alkane , and is the main constituent of natural gas . The relative abundance of methane on Earth makes it an attractive fuel , though capturing and storing it poses challenges due to its gaseous state under normal conditions for temperature and pressure . Natural methane is found both below ground and under the sea floor . When it reaches the surface and the atmosphere , it is known as atmospheric methane . The Earth 's atmospheric methane concentration has increased by about 150 % since 1750 , and it accounts for 20 % of the total radiative forcing from all of the long-lived and globally mixed greenhouse gases ( these gases do n't include water vapor which is by far the largest component of the greenhouse effect ) . |
2743 | Global_warming | "a [cloudcover] change in the Tropics could lead to a negative feedback in the global climate, with a feedback factor of about –1.1, which if correct, would more than cancel all the positive feedbacks in the more sensitive current climate models" (Lindzen et al. | 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 . |
2939 | Mesozoic | "The climate of this planet oscillates between periods of approximately 30 years of warming followed by approximately 30 years of cooling. | Mesozoic The Mesozoic Era ( -LSB- pronˌmɛsəˈzoʊɪk , _ ˌmiː - , _ - soʊ - -RSB- or -LSB- ˌmɛzəˈzoʊɪk , _ ˌmiː - , _ - soʊ - -RSB- ) is an interval of geological time from about . It is also called the Age of Reptiles , a phrase introduced by the 19th century paleontologist Gideon Mantell who viewed it as dominated by diapsids such as Iguanodon , Megalosaurus , Plesiosaurus and Pterodactylus . This Era is also called from a paleobotanist view the Age of Conifers . Mesozoic means `` middle life '' , deriving from the Greek prefix meso - / μεσο - for `` between '' and zōon / ζῷον meaning `` animal '' or `` living being '' . It is one of three geologic eras of the Phanerozoic Eon , preceded by the Paleozoic ( `` ancient life '' ) and succeeded by the Cenozoic ( `` new life '' ) . The era is subdivided into three major periods : the Triassic , Jurassic , and Cretaceous , which are further subdivided into a number of epochs and stages . The era began in the wake of the Permian -- Triassic extinction event , the largest well-documented mass extinction in Earth 's history , and ended with the Cretaceous -- Paleogene extinction event , another mass extinction which is known for having killed off non-avian dinosaurs , as well as other plant and animal species . The Mesozoic was a time of significant tectonic , climate and evolutionary activity . The era witnessed the gradual rifting of the supercontinent Pangaea into separate landmasses that would eventually move into their current positions . The climate of the Mesozoic was varied , alternating between warming and cooling periods . Overall , however , the Earth was hotter than it is today . Dinosaurs appeared in the Late Triassic and became the dominant terrestrial vertebrates early in the Jurassic , occupying this position for about 135 million years until their demise at the end of the Cretaceous . Birds first appeared in the Jurassic , having evolved from a branch of theropod dinosaurs . The first mammals also appeared during the Mesozoic , but would remain small -- less than 15 kg ( 33 lb ) -- until the Cenozoic . |
316 | James_Hansen | the models predicted seven times as much warming as has been observed | James Hansen James Edward Hansen ( born 29 March 1941 ) is an American adjunct professor in the Department of Earth and Environmental Sciences at Columbia University . He is best known for his research in climatology , his 1988 Congressional testimony on climate change that helped raise broad awareness of global warming , and his advocacy of action to avoid dangerous climate change . In recent years he has become a climate activist to mitigate the effects of climate change , on a few occasions leading to his arrest . In 2000 , Hansen advanced an alternative view of global warming over the last 100 years , arguing that during that time frame the negative forcing via aerosols and the positive forcing via largely balanced each other out , and that the 0.74 ± 0.18 ° C net rise in average global temperatures could mostly be explained by greenhouse gases other than carbon dioxide , such as methane and chlorofluorocarbons . However , even then he wrote `` the future balance of forcings is likely to shift toward dominance of CO2 over aerosols '' |
2060 | Global_warming | Global warming is causing more hurricanes and stronger hurricanes. | 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 . |
859 | Severe_weather | By 2080, without dramatic reductions in emissions, southern Europe will be in permanent extreme drought, much worse than the American dust bowl ever was. | Severe weather Severe weather refers to any dangerous meteorological phenomena with the potential to cause damage , serious social disruption , or loss of human life . Types of severe weather phenomena vary , depending on the latitude , altitude , topography , and atmospheric conditions . High winds , hail , excessive precipitation , and wildfires are forms and effects of severe weather , as are thunderstorms , downbursts , lightning , tornadoes , waterspouts , tropical cyclones , and extratropical cyclones . Regional and seasonal severe weather phenomena include blizzards , snowstorms , ice storms , and duststorms . |
2888 | Climatic_Research_Unit_email_controversy | But Trenberth's "lack of warming at the moment" has been going on at least a decade. | Climatic Research Unit email controversy The Climatic Research Unit email controversy ( also known as `` Climategate '' ) began in November 2009 with the hacking of a server at the Climatic Research Unit ( CRU ) at the University of East Anglia ( UEA ) by an external attacker , copying thousands of emails and computer files , the Climatic Research Unit documents , to various internet locations several weeks before the Copenhagen Summit on climate change . The story was first broken by climate change denialists with columnist James Delingpole popularising the term `` Climategate '' to describe the controversy . Several people considered climate change `` skeptics '' argued that the emails showed global warming was a scientific conspiracy , that scientists manipulated climate data and attempted to suppress critics . The CRU rejected this , saying the emails had been taken out of context and merely reflected an honest exchange of ideas . The mainstream media picked up the story as negotiations over climate change mitigation began in Copenhagen on 7 December 2009 . Because of the timing , scientists , policy makers and public relations experts said that the release of emails was a smear campaign intended to undermine the climate conference . In response to the controversy , the American Association for the Advancement of Science ( AAAS ) , the American Meteorological Society ( AMS ) and the Union of Concerned Scientists ( UCS ) released statements supporting the scientific consensus that the Earth 's mean surface temperature had been rising for decades , with the AAAS concluding , `` based on multiple lines of scientific evidence that global climate change caused by human activities is now underway ... it is a growing threat to society . '' Eight committees investigated the allegations and published reports , finding no evidence of fraud or scientific misconduct . However , the reports called on the scientists to avoid any such allegations in the future by taking steps to regain public confidence in their work , for example by opening up access to their supporting data , processing methods and software , and by promptly honouring freedom of information requests . The scientific consensus that global warming is occurring as a result of human activity remained unchanged throughout the investigations . |
1702 | Greenhouse_gas | CO2 levels are measured by hundreds of stations across the globe, all reporting the same trend. | 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 . |
1512 | Scientific_consensus_on_climate_change | more than 100 per cent of the warming over the past century is due to human actions. | 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. |
180 | Carbon_sink | Reef material is calcium carbonate, which contains 44 per cent carbon dioxide. | Carbon sink A carbon sink is a natural or artificial reservoir that accumulates and stores some carbon-containing chemical compound for an indefinite period . The process by which carbon sinks remove carbon dioxide from the atmosphere is known as carbon sequestration . Public awareness of the significance of CO2 sinks has grown since passage of the Kyoto Protocol , which promotes their use as a form of carbon offset . There are also different strategies used to enhance this process . |
774 | Ice_age | The warming is extremely rapid on the geologic time scale, and no other factor can explain it as well as human emissions of greenhouse gases. | 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 . |
1923 | Infrastructure_policy_of_Donald_Trump | More than 260,000 Americans are employed by the domestic solar industry — three times as many workers as employed by the entire coal mining industry. | Infrastructure policy of Donald Trump The infrastructure policy of Donald Trump includes ensuring U.S. energy independence (by catering to the fossil fuel, nuclear, and renewable energy industries), safeguarding the cybersecurity of the national power grid and other critical infrastructure, locking China out of the U.S. fifth-generation Internet market, and rolling back regulations to ease the process of planning and construction. While there have been no major infrastructure spending packages yet, some individual policies and projects have advanced piecemeal, especially in rural areas. Although there is recognition of the need to upgrade American infrastructure from both sides of the political aisle, as of April 2020, no major infrastructure bill has been passed due to disagreements over the details of such a spending package, namely, what to spend on, how much to spend, and how to pay for it. 'Infrastructure' is a rather broad term that means different things to different people. In general, the aim of the Trump administration is revitalizing the national economy and enhancing national security despite the tendency of his own Republican Party to oppose large federal expenditures and tax hikes whereas members of the opposition Democratic Party typically favor investing in renewable energy and new infrastructure that could combat climate change, and tend to be less averse to deficit spending. This article focuses exclusively on physical or hard infrastructure, as opposed to soft infrastructure, or public institutions. |
2247 | Kyoto_Protocol | His best estimate is that the warming in response to a doubling of CO2 concentration, which may happen this century unless the usual suspects get away with shutting down the economies of the West, will be a harmless 1 Fahrenheit degree, not the 6 F predicted by the IPCC." | Kyoto Protocol The Kyoto Protocol is an international treaty which extends the 1992 United Nations Framework Convention on Climate Change ( UNFCCC ) that commits State Parties to reduce greenhouse gas emissions , based on the fact that ( a ) global warming exists and ( b ) human-made CO2 emissions have caused it . The Kyoto Protocol was adopted in Kyoto , Japan , on 11 December 1997 and entered into force on 16 February 2005 . There are currently 192 parties ( Canada withdrew effective December 2012 ) to the Protocol . The Kyoto Protocol implemented the objective of the UNFCCC to fight global warming by reducing greenhouse gas concentrations in the atmosphere to `` a level that would prevent dangerous anthropogenic interference with the climate system '' ( Art. 2 ) . The Protocol is based on the principle of common but differentiated responsibilities : it puts the obligation to reduce current emissions on developed countries on the basis that they are historically responsible for the current levels of greenhouse gases in the atmosphere . The Protocol 's first commitment period started in 2008 and ended in 2012 . A second commitment period was agreed on in 2012 , known as the Doha Amendment to the protocol , in which 37 countries have binding targets : Australia , the European Union ( and its 28 member states ) , Belarus , Iceland , Kazakhstan , Liechtenstein , Norway , Switzerland , and Ukraine . Belarus , Kazakhstan and Ukraine have stated that they may withdraw from the Protocol or not put into legal force the Amendment with second round targets . Japan , New Zealand and Russia have participated in Kyoto 's first-round but have not taken on new targets in the second commitment period . Other developed countries without second-round targets are Canada ( which withdrew from the Kyoto Protocol in 2012 ) and the United States ( which has not ratified the Protocol ) . As of July 2016 , 66 states have accepted the Doha Amendment , while entry into force requires the acceptances of 144 states . Of the 37 countries with binding commitments , 7 have ratified . Negotiations were held in the framework of the yearly UNFCCC Climate Change Conferences on measures to be taken after the second commitment period ends in 2020 . This resulted in the 2015 adoption of the Paris Agreement , which is a separate instrument under the UNFCCC rather than an amendment of the Kyoto protocol . |
1793 | North_Pole | While summer maximums have showed little trend, the annual average Arctic temperature has risen sharply in recent decades. | 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 . |
3058 | Tropical_cyclone | Correspondingly, the global surface temperature has also dropped." | Tropical cyclone A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center , a closed low-level atmospheric circulation , strong winds , and a spiral arrangement of thunderstorms that produce heavy rain . Depending on its location and strength , a tropical cyclone is referred to by names such as hurricane ( -LSB- ˈhʌrᵻkən -RSB- or -LSB- ˈhʌrᵻkeɪn -RSB- ) , typhoon -LSB- taɪ ` fuːn -RSB- , tropical storm , cyclonic storm , tropical depression , and simply cyclone . A hurricane is a storm that occurs in the Atlantic Ocean and northeastern Pacific Ocean , a typhoon occurs in the northwestern Pacific Ocean , and a cyclone occurs in the south Pacific or Indian Ocean . Tropical cyclones typically form over large bodies of relatively warm water . They derive their energy through the evaporation of water from the ocean surface , which ultimately recondenses into clouds and rain when moist air rises and cools to saturation . This energy source differs from that of mid-latitude cyclonic storms , such as nor'easter s and European windstorms , which are fueled primarily by horizontal temperature contrasts . The strong rotating winds of a tropical cyclone are a result of the conservation of angular momentum imparted by the Earth 's rotation as air flows inwards toward the axis of rotation . As a result , they rarely form within 5 ° of the equator . Tropical cyclones are typically between 100 and in diameter . Tropical refers to the geographical origin of these systems , which form almost exclusively over tropical seas . Cyclone refers to their cyclonic nature , with wind blowing counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere . The opposite direction of circulation is due to the Coriolis effect . In addition to strong winds and rain , tropical cyclones are capable of generating high waves , damaging storm surge , and tornadoes . They typically weaken rapidly over land where they are cut off from their primary energy source . For this reason , coastal regions are particularly vulnerable to damage from a tropical cyclone as compared to inland regions . Heavy rains , however , can cause significant flooding inland , and storm surges can produce extensive coastal flooding up to 40 km from the coastline . Though their effects on human populations are often devastating , tropical cyclones can relieve drought conditions . They also carry heat energy away from the tropics and transport it toward temperate latitudes , which may play an important role in modulating regional and global climate . |
2800 | Climate_sensitivity | Elementary radiative-transfer calculations demonstrate that a natural surface global brightening amounting to ~1.9 Wm–2 over the 18-year period of study would be expected – using the IPCC's own methodology – to have caused a transient warming of 1 K (1.8 F°). | Climate sensitivity Climate sensitivity is the equilibrium temperature change in response to changes of the radiative forcing . Therefore , climate sensitivity depends on the initial climate state , but potentially can be accurately inferred from precise palaeoclimate data . Slow climate feedbacks , especially changes of ice sheet size and atmospheric CO2 , amplify the total Earth system sensitivity by an amount that depends on the time scale considered . Although climate sensitivity is usually used in the context of radiative forcing by carbon dioxide ( CO2 ) , it is thought of as a general property of the climate system : the change in surface air temperature ( ΔTs ) following a unit change in radiative forcing ( RF ) , and thus is expressed in units of ° C / ( W/m2 ) . For this to be useful , the measure must be independent of the nature of the forcing ( e.g. from greenhouse gases or solar variation ) ; to first order this is indeed found to be so . The climate sensitivity specifically due to is often expressed as the temperature change in ° C associated with a doubling of the concentration of carbon dioxide in Earth 's atmosphere . For coupled atmosphere-ocean global climate models ( e.g. CMIP5 ) the climate sensitivity is an emergent property : it is not a model parameter , but rather a result of a combination of model physics and parameters . By contrast , simpler energy-balance models may have climate sensitivity as an explicit parameter . The terms represented in the equation relate radiative forcing ( RF ) to linear changes in global surface temperature change ( ΔTs ) via the climate sensitivity λ . It is also possible to estimate climate sensitivity from observations ; however , this is difficult due to uncertainties in the forcing and temperature histories . |
2431 | La_Niña | Short term cooling over the last few years is largely due to a strong La Nina phase in the Pacific Ocean and a prolonged solar minimum. | La Niña La Niña ( -LSB- lɑːˈniːnjə -RSB- , -LSB- la ˈniɲa -RSB- ) is a coupled ocean-atmosphere phenomenon that is the counterpart of El Niño as part of the broader El Niño -- Southern Oscillation climate pattern . The name La Niña originates from Spanish , meaning `` the little girl '' , analogous to El Niño meaning `` the little boy '' . It has also in the past been called anti-El Niño , and El Viejo ( meaning `` the old man '' ) . During a period of La Niña , the sea surface temperature across the equatorial Eastern Central Pacific Ocean will be lower than normal by 3 to 5 ° C . In the United States , an appearance of La Niña persists for at least five months . It has extensive effects on the weather in North America , even affecting the Atlantic Hurricane Season . |
322 | Sea_level | The first adjustment changed how the temperature of the ocean surface is calculated, by replacing satellite data with drifting buoys and temperatures in ships' water intake. | Sea level Mean sea level ( MSL ) ( abbreviated simply sea level ) is an average level of the surface of one or more of Earth 's oceans from which heights such as elevations may be measured . MSL is a type of vertical datuma standardised geodetic reference pointthat is used , for example , as a chart datum in cartography and marine navigation , or , in aviation , as the standard sea level at which atmospheric pressure is measured in order to calibrate altitude and , consequently , aircraft flight levels . A common and relatively straightforward mean sea-level standard is the midpoint between a mean low and mean high tide at a particular location . Sea levels can be affected by many factors and are known to have varied greatly over geological time scales . The careful measurement of variations in MSL can offer insights into ongoing climate change , and sea level rise has been widely quoted as evidence of ongoing global warming . The term above sea level generally refers to above mean sea level ( AMSL ) . |
1386 | Environmental_impact_of_wind_power | "Global warming alarmists' preferred electricity source – wind power – kills nearly 1 million bats every year (to say nothing of the more than 500,000 birds killed every year) in the United States alone. | Environmental impact of wind power The environmental impact of wind power when compared to the environmental impacts of fossil fuels , is relatively minor . Compared with other low carbon power sources , wind turbines have some of the lowest global warming potential per unit of electrical energy generated . According to the IPCC , in assessments of the life-cycle global warming potential of energy sources , wind turbines have a median value of between 15 and 11 ( geq/kWh ) depending on whether off - or onshore turbines are being assessed . While wind turbine installations may cover a large area , they are compatible with many land uses such as farming and grazing , as only small areas of turbine foundations and infrastructure are made unavailable for use . Wind turbines generate some noise . At a residential distance of 300 m this may be around 45 dB , which is slightly louder than a refrigerator . At 1.5 km distance most wind turbines become inaudible . From a fundamental biological point of view , it is known that loud noise increases stress and stress causes diseases . Peer-reviewed research has generally supported the view that when properly sited wind turbines do not affect human health from noise . However , when improperly sited , data from the monitoring of two groups of growing geese revealed substantially lower body weights and higher concentrations of a stress hormone in the blood of the first group of geese who were situated 50 meters away compared to a second group which was at a distance of 500 meters from the turbine . Aesthetic aspects of wind turbines and resulting changes of the visual landscape can be significant . Conflicts arise especially in scenic and heritage protected landscapes . Siting restrictions ( such as setbacks ) have often been implemented to limit any intrusive environmental impacts . There are reports of bird and bat mortality at wind turbines as there are around other artificial structures . The scale of the ecological impact may or may not be significant , depending on specific circumstances . Prevention and mitigation of wildlife fatalities , and protection of peat bogs , affect the siting and operation of wind turbines . |
978 | Sahara | The extreme cycles of dry and wet weather appear to have been intensifying over the last three decades. | Sahara The Sahara ( الصحراء الكبرى , , ` the Greatest Desert ' ) is the largest hot desert and the third largest desert in the world after Antarctica and the Arctic . Its area of 9200000 km2 is comparable to the area of the United States . The desert comprises much of North Africa , excluding the fertile region on the Mediterranean Sea coast , the Atlas Mountains of the Maghreb , and the Nile Valley in Egypt and Sudan . It stretches from the Red Sea in the east and the Mediterranean in the north to the Atlantic Ocean in the west , where the landscape gradually changes from desert to coastal plains . To the south , it is bounded by the Sahel , a belt of semi-arid tropical savanna around the Niger River valley and the Sudan Region of Sub-Saharan Africa . The Sahara can be divided into several regions including : the western Sahara , the central Ahaggar Mountains , the Tibesti Mountains , the Aïr Mountains , the Ténéré desert , and the Libyan Desert . The name ` Sahara ' is derived from ( , pronounced -LSB- / / ˈSaHa : ra : -RSB- ) , the plural of the Arabic word for `` desert '' . |
2834 | Ice_core | When stomata-derived CO2 (red) is compared to ice core-derived CO2 (blue), the stomata generally show much more variability in the atmospheric CO2 level and often show levels much higher than the ice cores. | Ice core An ice core is a core sample that is typically removed from an ice sheet , most commonly from the polar ice caps of Antarctica , Greenland or from high mountain glaciers elsewhere . As the ice forms from the incremental buildup of annual layers of snow , lower layers are older than upper , and an ice core contains ice formed over a range of years . The properties of the ice and the recrystallized inclusions within the ice can then be used to reconstruct a climatic record over the age range of the core , normally through isotopic analysis . This enables the reconstruction of local temperature records and the history of atmospheric composition . Ice cores contain an abundance of information about climate . Inclusions in the snow of each year remain in the ice , such as wind-blown dust , ash , pollen , bubbles of atmospheric gas and radioactive substances . The variety of climatic proxies is greater than in any other natural recorder of climate , such as tree rings or sediment layers . These include ( proxies for ) temperature , ocean volume , precipitation , chemistry and gas composition of the lower atmosphere , volcanic eruptions , solar variability , sea-surface productivity , desert extent and forest fires . The length of the record depends on the depth of the ice core and varies from a few years up to 800 kyr ( 800,000 years ) for the EPICA core . The time resolution ( i.e. the shortest time period which can be accurately distinguished ) depends on the amount of annual snowfall , and reduces with depth as the ice compacts under the weight of layers accumulating on top of it . Upper layers of ice in a core correspond to a single year or sometimes a single season . Deeper into the ice the layers thin and annual layers become indistinguishable . An ice core from the right site can be used to reconstruct an uninterrupted and detailed climate record extending over hundreds of thousands of years , providing information on a wide variety of aspects of climate at each point in time . It is the simultaneity of these properties recorded in the ice that makes ice cores such a powerful tool in paleoclimate research . |
2060 | Scientific_consensus_on_climate_change | Global warming is causing more hurricanes and stronger hurricanes. | 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. |
2136 | Wind_power | Renewables can't provide baseload power | Wind power Wind power is the use of air flow through wind turbines to mechanically power generators for electric power . Wind power , as an alternative to burning fossil fuels , is plentiful , renewable , widely distributed , clean , produces no greenhouse gas emissions during operation , consumes no water , and uses little land . The net effects on the environment are far less problematic than those of nonrenewable power sources . Wind farms consist of many individual wind turbines which are connected to the electric power transmission network . Onshore wind is an inexpensive source of electric power , competitive with or in many places cheaper than coal or gas plants . Offshore wind is steadier and stronger than on land , and offshore farms have less visual impact , but construction and maintenance costs are considerably higher . Small onshore wind farms can feed some energy into the grid or provide electric power to isolated off-grid locations . Wind power gives variable power which is very consistent from year to year but which has significant variation over shorter time scales . It is therefore used in conjunction with other electric power sources to give a reliable supply . As the proportion of wind power in a region increases , a need to upgrade the grid , and a lowered ability to supplant conventional production can occur . Power management techniques such as having excess capacity , geographically distributed turbines , dispatchable backing sources , sufficient hydroelectric power , exporting and importing power to neighboring areas , using vehicle-to-grid strategies or reducing demand when wind production is low , can in many cases overcome these problems . In addition , weather forecasting permits the electric power network to be readied for the predictable variations in production that occur . As of 2015 , Denmark generates 40 % of its electric power from wind , and at least 83 other countries around the world are using wind power to supply their electric power grids . In 2014 global wind power capacity expanded 16 % to 369,553 MW . Yearly wind energy production is also growing rapidly and has reached around 4 % of worldwide electric power usage , 11.4 % in the EU . |
621 | Thunderstorm | Dr. Gutzler said spring temperatures have an impact, too, with warmer air causing more snow to turn to vapor and essentially disappear. | Thunderstorm A thunderstorm , also known as an electrical storm , lightning storm , or thundershower , is a storm characterized by the presence of lightning and its acoustic effect on the Earth 's atmosphere , known as thunder . Thunderstorms occur in association with a type of cloud known as a cumulonimbus . They are usually accompanied by strong winds , heavy rain , and sometimes snow , sleet , hail , or , in contrast , no precipitation at all . Thunderstorms may line up in a series or become a rainband , known as a squall line . Strong or severe thunderstorms , known as supercells , rotate as do cyclones . While most thunderstorms move with the mean wind flow through the layer of the troposphere that they occupy , vertical wind shear sometimes causes a deviation in their course at a right angle to the wind shear direction . Thunderstorms result from the rapid upward movement of warm , moist air , sometimes along a front . As the warm , moist air moves upward , it cools , condenses , and forms a cumulonimbus cloud that can reach heights of over 20 km . As the rising air reaches its dew point temperature , water vapor condenses into water droplets or ice , reducing pressure locally within the thunderstorm cell . Any precipitation falls the long distance through the clouds towards the Earth 's surface . As the droplets fall , they collide with other droplets and become larger . The falling droplets create a downdraft as it pulls cold air with it , and this cold air spreads out at the Earth 's surface , occasionally causing strong winds that are commonly associated with thunderstorms . Thunderstorms can form and develop in any geographic location but most frequently within the mid-latitude , where warm , moist air from tropical latitudes collides with cooler air from polar latitudes . Thunderstorms are responsible for the development and formation of many severe weather phenomena . Thunderstorms , and the phenomena that occur along with them , pose great hazards . Damage that results from thunderstorms is mainly inflicted by downburst winds , large hailstones , and flash flooding caused by heavy precipitation . Stronger thunderstorm cells are capable of producing tornadoes and waterspouts . There are four types of thunderstorms : single-cell , multi-cell cluster , multi-cell lines , and supercells . Supercell thunderstorms are the strongest and the most associated with severe weather phenomena . Mesoscale convective systems formed by favorable vertical wind shear within the tropics and subtropics can be responsible for the development of hurricanes . Dry thunderstorms , with no precipitation , can cause the outbreak of wildfires from the heat generated from the cloud-to-ground lightning that accompanies them . Several means are used to study thunderstorms : weather radar , weather stations , and video photography . Past civilizations held various myths concerning thunderstorms and their development as late as the 18th century . Beyond the Earth 's atmosphere , thunderstorms have also been observed on the planets of Jupiter , Saturn , Neptune , and , probably , Venus . |
1523 | Scientific_consensus_on_climate_change | Research has found a human influence on the climate of the past several decades ... | 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. |
2200 | Scientific_consensus_on_climate_change | The Petition Project features over 31,000 scientists signing the petition stating "There is no convincing scientific evidence that human release of carbon dioxide will, in the forseeable future, cause catastrophic heating of the Earth's atmosphere ...". | 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. |
1721 | 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 . |
1401 | Polar_ice_cap | As a result, the polar ice caps were quite likely more extensive than they had been since at least the 1920s. | Polar ice cap A polar ice cap or polar cap is a high-latitude region of a planet , dwarf planet , or natural satellite that is covered in ice . There are no requirements with respect to size or composition for a body of ice to be termed a polar ice cap , nor any geological requirement for it to be over land ; only that it must be a body of solid phase matter in the polar region . This causes the term `` polar ice cap '' to be something of a misnomer , as the term ice cap itself is applied more narrowly to bodies that are over land , and cover less than 50,000 km ² : larger bodies are referred to as ice sheets . The composition of the ice will vary . For example , Earth 's polar caps are mainly water ice , whereas Mars 's polar ice caps are a mixture of solid carbon dioxide and water ice . Polar ice caps form because high-latitude regions receive less energy in the form of solar radiation from the Sun than equatorial regions , resulting in lower surface temperatures . Earth 's polar caps have changed dramatically over the last 12,000 years . Seasonal variations of the ice caps takes place due to varied solar energy absorption as the planet or moon revolves around the Sun . Additionally , in geologic time scales , the ice caps may grow or shrink due to climate variation . |
823 | El_Niño | 'Extremely remarkable' 2017 heads toward record for hottest year without an El Niño episode. | 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 '' . |
1505 | Global_warming | according, again, to the official figures—during this past 10 years, if anything, mean global temperature, average world temperature, has slightly declined. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
2453 | Ordovician | "The killer proof that CO2 does not drive climate is to be found during the Ordovician- Silurian and the Jurassic-Cretaceous periods when CO2 levels were greater than 4000 ppmv (parts per million by volume) and about 2000 ppmv respectively. | Ordovician The Ordovician ( -LSB- pronɔrdəˈvɪʃən -RSB- ) is a geologic period and system , the second of six periods of the Paleozoic Era . The Ordovician spans 41.2 million years from the end of the Cambrian Period million years ago ( Mya ) to the start of the Silurian Period Mya . The Ordovician , named after the Celtic tribe of the Ordovices , was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison , who were placing the same rock beds in northern Wales into the Cambrian and Silurian periods , respectively . Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian periods , and placed them in a period of their own . It received international sanction in 1960 , when it was adopted as an official period of the Paleozoic Era by the International Geological Congress . Life continued to flourish during the Ordovician as it did in the earlier Cambrian period , although the end of the period was marked by the Ordovician -- Silurian extinction event . Invertebrates , namely molluscs and arthropods , dominated the oceans . The Great Ordovician Biodiversification Event considerably increased the diversity of life . Fish , the world 's first true vertebrates , continued to evolve , and those with jaws may have first appeared late in the period . Life had yet to diversify on land . About 100 times as many meteorites struck the Earth during the Ordovician compared with today . |
1198 | Natural_gas | " 'You see, gas in America is incredibly cheap, because of fracking,' he says. | Natural gas Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of methane , but commonly including varying amounts of other higher alkanes , and sometimes a small percentage of carbon dioxide , nitrogen , hydrogen sulfide , or helium . It is formed when layers of decomposing plant and animal matter are exposed to intense heat and pressure under the surface of the Earth over millions of years . The energy that the plants originally obtained from the sun is stored in the form of chemical bonds in the gas . Natural gas is a fossil fuel used as a source of energy for heating , cooking , and electricity generation . It is also used as fuel for vehicles and as a chemical feedstock in the manufacture of plastics and other commercially important organic chemicals . Fossil fuel based natural gas is a non-renewable resource . Natural gas is found in deep underground rock formations or associated with other hydrocarbon reservoirs in coal beds and as methane clathrates . Petroleum is another resource and fossil fuel found in close proximity to and with natural gas . Most natural gas was created over time by two mechanisms : biogenic and thermogenic . Biogenic gas is created by methanogenic organisms in marshes , bogs , landfills , and shallow sediments . Deeper in the earth , at greater temperature and pressure , thermogenic gas is created from buried organic material . In petroleum production gas is often burnt as flare gas . The World Bank estimates that over 150 cubic kilometers of natural gas are flared or vented annually . Before natural gas can be used as a fuel , most , but not all , must be processed to remove impurities , including water , to meet the specifications of marketable natural gas . The by-products of this processing include : ethane , propane , butanes , pentanes , and higher molecular weight hydrocarbons , hydrogen sulfide ( which may be converted into pure sulfur ) , carbon dioxide , water vapor , and sometimes helium and nitrogen . Natural gas is often informally referred to simply as `` gas '' , especially when compared to other energy sources such as oil or coal . However , it is not to be confused with gasoline , especially in North America , where the term gasoline is often shortened in colloquial usage to gas . Natural gas was used by the Chinese in about 500 BCE ( possibly even 1000 BCE ) . They discovered a way to transport gas seeping from the ground in crude pipelines of bamboo to where it was used to boil salt water to extract the salt , in the Ziliujing District of Sichuan . The world 's first industrial extraction of natural gas started at Fredonia , New York , United States in 1825 . By 2009 , 66 000 km ³ ( or 8 % ) had been used out of the total 850 000 km ³ of estimated remaining recoverable reserves of natural gas . Based on an estimated 2015 world consumption rate of about 3400 km ³ of gas per year , the total estimated remaining economically recoverable reserves of natural gas would last 250 years at current consumption rates . An annual increase in usage of 2 -- 3 % could result in currently recoverable reserves lasting significantly less , perhaps as few as 80 to 100 years . |
752 | Energy_in_South_Australia | [South Australia] has the most expensive electricity in the world. | Energy in South Australia South Australia is rich in energy resources . It contains significant reserves of fossil fuels such as natural gas , coal , and oil -- although there are incentives to phase these out in favour of clean energy . The state also contains large amounts of uranium , including the world 's single biggest deposit at Olympic Dam , which represents 30 % of the world 's total resource . More recently , the State has seen a rapid increase in investment in renewable energy , and is now the leading producer of wind power in Australia . South Australia has been noted for the availability of hot rocks suitable for geothermal electricity generation . The South Australian Government has released plans to make South Australia a green energy hub for Australia 's eastern seaboard . |
1466 | Sea | This increase is the result of humans emitting more carbon dioxide into the atmosphere and hence more being absorbed into the oceans. | 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 . |
490 | Special_Report_on_Global_Warming_of_1.5_°C | IPCC report warning last week the world is "nowhere near on track" to meet its Paris commitments | Special Report on Global Warming of 1.5 °C The Special Report on Global Warming of 1.5 °C (SR15) was published by the Intergovernmental Panel on Climate Change (IPCC) on 8 October 2018. The report, approved in Incheon, South Korea, includes over 6,000 scientific references, and was prepared by 91 authors from 40 countries. In December 2015, the 2015 United Nations Climate Change Conference called for the report. The report was delivered at the United Nations' 48th session of the IPCC to "deliver the authoritative, scientific guide for governments" to deal with climate change.Its key finding is that meeting a 1.5 °C (2.7 °F) target is possible but would require "deep emissions reductions" and "rapid, far-reaching and unprecedented changes in all aspects of society." Furthermore, the report finds that "limiting global warming to 1.5 °C compared with 2 °C would reduce challenging impacts on ecosystems, human health and well-being" and that a 2 °C temperature increase would exacerbate extreme weather, rising sea levels and diminishing Arctic sea ice, coral bleaching, and loss of ecosystems, among other impacts. SR15 also has modelling that shows that, for global warming to be limited to 1.5 °C, "Global net human-caused emissions of carbon dioxide (CO2) would need to fall by about 45 percent from 2010 levels by 2030, reaching 'net zero' around 2050." The reduction of emissions by 2030 and its associated changes and challenges, including rapid decarbonisation, was a key focus on much of the reporting which was repeated through the world. |
2365 | IPCC_Fourth_Assessment_Report | Comparisons to the most recent data consistently finds that climate change is occurring more rapidly and intensely than indicated by IPCC predictions. | IPCC Fourth Assessment Report Climate Change 2007 , the Fourth Assessment Report ( AR4 ) of the United Nations Intergovernmental Panel on Climate Change ( IPCC ) , is the fourth in a series of reports intended to assess scientific , technical and socio-economic information concerning climate change , its potential effects , and options for adaptation and mitigation . The report is the largest and most detailed summary of the climate change situation ever undertaken , produced by thousands of authors , editors , and reviewers from dozens of countries , citing over 6,000 peer-reviewed scientific studies . It supersedes the Third Assessment Report ( 2001 ) , and is superseded by the Fifth Assessment Report . The headline findings of the report were : `` warming of the climate system is unequivocal '' , and `` most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations . '' |
1908 | Natural_gas | In reality, gas produced by fracking is worse for the climate than coal. | Natural gas Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of methane , but commonly including varying amounts of other higher alkanes , and sometimes a small percentage of carbon dioxide , nitrogen , hydrogen sulfide , or helium . It is formed when layers of decomposing plant and animal matter are exposed to intense heat and pressure under the surface of the Earth over millions of years . The energy that the plants originally obtained from the sun is stored in the form of chemical bonds in the gas . Natural gas is a fossil fuel used as a source of energy for heating , cooking , and electricity generation . It is also used as fuel for vehicles and as a chemical feedstock in the manufacture of plastics and other commercially important organic chemicals . Fossil fuel based natural gas is a non-renewable resource . Natural gas is found in deep underground rock formations or associated with other hydrocarbon reservoirs in coal beds and as methane clathrates . Petroleum is another resource and fossil fuel found in close proximity to and with natural gas . Most natural gas was created over time by two mechanisms : biogenic and thermogenic . Biogenic gas is created by methanogenic organisms in marshes , bogs , landfills , and shallow sediments . Deeper in the earth , at greater temperature and pressure , thermogenic gas is created from buried organic material . In petroleum production gas is often burnt as flare gas . The World Bank estimates that over 150 cubic kilometers of natural gas are flared or vented annually . Before natural gas can be used as a fuel , most , but not all , must be processed to remove impurities , including water , to meet the specifications of marketable natural gas . The by-products of this processing include : ethane , propane , butanes , pentanes , and higher molecular weight hydrocarbons , hydrogen sulfide ( which may be converted into pure sulfur ) , carbon dioxide , water vapor , and sometimes helium and nitrogen . Natural gas is often informally referred to simply as `` gas '' , especially when compared to other energy sources such as oil or coal . However , it is not to be confused with gasoline , especially in North America , where the term gasoline is often shortened in colloquial usage to gas . Natural gas was used by the Chinese in about 500 BCE ( possibly even 1000 BCE ) . They discovered a way to transport gas seeping from the ground in crude pipelines of bamboo to where it was used to boil salt water to extract the salt , in the Ziliujing District of Sichuan . The world 's first industrial extraction of natural gas started at Fredonia , New York , United States in 1825 . By 2009 , 66 000 km ³ ( or 8 % ) had been used out of the total 850 000 km ³ of estimated remaining recoverable reserves of natural gas . Based on an estimated 2015 world consumption rate of about 3400 km ³ of gas per year , the total estimated remaining economically recoverable reserves of natural gas would last 250 years at current consumption rates . An annual increase in usage of 2 -- 3 % could result in currently recoverable reserves lasting significantly less , perhaps as few as 80 to 100 years . |
2895 | Gravity_of_Mars | 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. | Gravity of Mars The gravity of Mars is a natural phenomenon, due to the law of gravity, or gravitation, by which all things with mass around the planet Mars are brought towards it. It is weaker than Earth's gravity due to the planet's smaller mass. The average gravitational acceleration on Mars is 3.72076 ms−2 (about 38% of that of Earth) and it varies laterally. In general, topography-controlled isostasy drives the short wavelength free-air gravity anomalies. At the same time, convective flow and finite strength of the mantle lead to long-wavelength planetary-scale free-air gravity anomalies over the entire planet. Variation in crustal thickness, magmatic and volcanic activities, impact-induced Moho-uplift, seasonal variation of polar ice caps, atmospheric mass variation and variation of porosity of the crust could also correlate to the lateral variations. Over the years models consisting of an increasing but limited number of spherical harmonics have been produced. Maps produced have included free-air gravity anomaly, Bouguer gravity anomaly, and crustal thickness. In some areas of Mars there is a correlation between gravity anomalies and topography. Given the known topography, higher resolution gravity field can be inferred. Tidal deformation of Mars by the Sun or Phobos can be measured by its gravity. This reveals how stiff the interior is, and shows that the core is partially liquid. The study of surface gravity of Mars can therefore yield information about different features and provide beneficial information for future landing projects. |
1113 | Jet_stream | This means the jet stream meanders more, with big loops bringing warm air to the frozen north and cold air into warmer southern climes." | Jet stream Jet streams are fast flowing , narrow , meandering air currents found in the atmosphere of some planets , including Earth . On Earth , the main jet streams are located near the altitude of the tropopause and are westerly winds ( flowing west to east ) . Their paths typically have a meandering shape . Jet streams may start , stop , split into two or more parts , combine into one stream , or flow in various directions including opposite to the direction of the remainder of the jet . The strongest jet streams are the polar jets , at 9 - above sea level , and the higher altitude and somewhat weaker subtropical jets at 10 - . The Northern Hemisphere and the Southern Hemisphere each have a polar jet and a subtropical jet . The northern hemisphere polar jet flows over the middle to northern latitudes of North America , Europe , and Asia and their intervening oceans , while the southern hemisphere polar jet mostly circles Antarctica all year round . Jet streams are the product of two factors : the atmospheric heating by solar radiation that produces the large scale Polar , Ferrel , and Hadley circulation cells , and the action of the Coriolis force acting on those moving masses . The Coriolis force is caused by the planet 's rotation on its axis . On other planets , internal heat rather than solar heating drives their jet streams . The Polar jet stream forms near the interface of the Polar and Ferrel circulation cells ; while the subtropical jet forms near the boundary of the Ferrel and Hadley circulation cells . Other jet streams also exist . During the Northern Hemisphere summer , easterly jets can form in tropical regions , typically where dry air encounters more humid air at high altitudes . Low-level jets also are typical of various regions such as the central United States . Meteorologists use the location of some of the jet streams as an aid in weather forecasting . The main commercial relevance of the jet streams is in air travel , as flight time can be dramatically affected by either flying with the flow or against , which results in significant fuel and time cost savings for airlines . Often , the airlines work to fly ` with ' the jet stream for this reason . Dynamic North Atlantic Tracks are one example of how airlines and air traffic control work together to accommodate the jet steam and winds aloft that results in the maximum benefit for airlines and other users . Clear-air turbulence , a potential hazard to aircraft passenger safety , is often found in a jet stream 's vicinity , but it does not create a substantial alteration on flight times . |
447 | Global_warming | "Every day, nature puts twenty times as much carbon dioxide into the atmosphere as all of Earth industries. | 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 . |
335 | 2014_in_science | Last month was the hottest June ever recorded, European satellite agency announces | 2014 in science A number of significant scientific events occurred in 2014 , including the first robotic landing on a comet and the first complete stem-cell-assisted recovery from paraplegia . The year also saw a significant expansion in the worldwide use and sophistication of technologies such as unmanned aerial vehicles and wearable electronics . The United Nations declared 2014 the International Year of Family Farming and Crystallography . |
1375 | Earth | the world is barely half a degree Celsius (0.9 degrees Fahrenheit) warmer than it was about 35 years ago | 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 . |
1659 | Global_warming | Polar bears are in danger of extinction as well as many other species. | 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 . |
357 | Mind–body_dualism | With that in mind, they propose a plausible and terrifying "2050 scenario" whereby humanity could face irreversible collapse in just three decades. | Mind–body dualism Mind -- body dualism , or mind -- body duality , is a view in the philosophy of mind that mental phenomena are , in some respects , non-physical , or that the mind and body are distinct and separable . Thus , it encompasses a set of views about the relationship between mind and matter , and between subject and object , and is contrasted with other positions , such as physicalism and enactivism , in the mind -- body problem . Aristotle shared Plato 's view of multiple souls and further elaborated a hierarchical arrangement , corresponding to the distinctive functions of plants , animals , and people : a nutritive soul of growth and metabolism that all three share ; a perceptive soul of pain , pleasure , and desire that only people and other animals share ; and the faculty of reason that is unique to people only . In this view , a soul is the hylomorphic form of a viable organism , wherein each level of the hierarchy formally supervenes upon the substance of the preceding level . Thus , for Aristotle , all three souls perish when the living organism dies . For Plato however , the soul was not dependent on the physical body ; he believed in metempsychosis , the migration of the soul to a new physical body . Dualism is closely associated with the thought of René Descartes ( 1641 ) , which holds that the mind is a nonphysical -- and therefore , non-spatial -- substance . Descartes clearly identified the mind with consciousness and self-awareness and distinguished this from the brain as the seat of intelligence . Hence , he was the first to formulate the mind -- body problem in the form in which it exists today . Dualism is contrasted with various kinds of monism . Substance dualism is contrasted with all forms of materialism , but property dualism may be considered a form of emergent materialism or non-reductive physicalism in some sense . |
1130 | Holocene | The record warm years of 2015 and 2016 were primarily caused by the super El Nino.'" | Holocene The Holocene ( -LSB- pronˈhɒləˌsiːn , _ ˈhoʊ - -RSB- ) is the geological epoch that began after the Pleistocene at approximately 11,700 years before present . The term `` Recent '' ( usually capitalised ) has often been used as an exact synonym of `` Holocene '' , although this usage is discouraged in 21st-century science . The Holocene is part of the Quaternary period . Its name comes from the Ancient Greek words ὅλος ( holos , whole or entire ) and καινός ( kainos , new ) , meaning `` entirely recent '' . It has been identified with the current warm period , known as MIS 1 , and can be considered an interglacial in the current ice age based on that evidence . The Holocene also encompasses the growth and impacts of the human species worldwide , including all its written history , development of major civilizations , and overall significant transition toward urban living in the present . Human impacts on modern-era Earth and its ecosystems may be considered of global significance for future evolution of living species , including approximately synchronous lithospheric evidence , or more recently atmospheric evidence of human impacts . Given these , a new term , Anthropocene , is specifically proposed and used informally only for the very latest part of modern history involving significant human impact . |
1416 | Global_warming | In recent decades this warming has been accompanied by a constant rise in the sea level and, it would appear, by an increase of extreme weather events, even if a scientifically determinable cause cannot be assigned to each particular phenomenon. | 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 . |
1444 | Sustainability | Natural climate solutions like ending deforestation and restoring degraded forests could, at the global level, create 80 million jobs, bring 1 billion people out of poverty and add US$ 2.3 trillion in productive growth. | Sustainability In ecology , sustainability ( from sustain and ability ) is the property of biological systems to remain diverse and productive indefinite #Adjective . Long-lived and healthy wetlands and forests are examples of sustainable biological systems . In more general terms , sustainability is the endurance of systems and processes . The organizing principle for sustainability is sustainable development , which includes the four interconnected domains : ecology , economics , politics and culture . Sustainability science is the study of sustainable development and environmental science . Sustainability can also be defined as a socio-ecological process characterized by the pursuit of a common ideal . An ideal is by definition unattainable in a given time and space . However , by persistently and dynamically approaching it , the process results in a sustainable system . Healthy ecosystems and environments are necessary to the survival of humans and other organisms . Ways of reducing negative human impact are environmentally-friendly chemical engineering , environmental resources management and environmental protection . Information is gained from green chemistry , earth science , environmental science and conservation biology . Ecological economics studies the fields of academic research that aim to address human economies and natural ecosystems . Moving towards sustainability is also a social challenge that entails international and national law , urban planning and transport , local and individual lifestyles and ethical consumerism . Ways of living more sustainably can take many forms from reorganizing living conditions ( e.g. , ecovillages , eco-municipalities and sustainable cities ) , reappraising economic sectors ( permaculture , green building , sustainable agriculture ) , or work practices ( sustainable architecture ) , using science to develop new technologies ( green technologies , renewable energy and sustainable fission and fusion power ) , or designing systems in a flexible and reversible manner , and adjusting individual lifestyles that conserve natural resources . `` The term ` sustainability ' should be viewed as humanity 's target goal of human-ecosystem equilibrium ( homeostasis ) , while ` sustainable development ' refers to the holistic approach and temporal processes that lead us to the end point of sustainability . '' ( 305 ) Despite the increased popularity of the use of the term `` sustainability '' , the possibility that human societies will achieve environmental sustainability has been , and continues to be , questioned -- in light of environmental degradation , climate change , overconsumption , population growth and societies ' pursuit of unlimited economic growth in a closed system . |
1861 | California | California legislators have made it illegal for anyone to deny climate change, under threat of jail time. | California California ( -LSB- kælᵻˈfɔːrnjə , _ - ni.ə -RSB- , ) is the most populous state in the United States and the third most extensive by area . Located on the western ( Pacific Ocean ) coast of the U.S. , California is bordered by the other U.S. states of Oregon , Nevada , and Arizona and shares an international border with the Mexican state of Baja California . The state capital is Sacramento . Los Angeles is California 's most populous city , and the country 's second largest after New York City . The Greater Los Angeles Area and the San Francisco Bay Area are the nation 's second - and fifth-most populous urban regions , respectively . California also has the nation 's most populous county , Los Angeles County , and its largest county by area , San Bernardino County . California 's diverse geography ranges from the Pacific Coast in the west to the Sierra Nevada mountain range in the east ; and from the redwood -- Douglas fir forests in the northwest to the Mojave Desert in the southeast . The Central Valley , a major agricultural area , dominates the state 's center . Though California is well-known for its warm Mediterranean climate , the large size of the state means it can vary from moist temperate rainforest in the north , to arid desert in the interior , as well as snowy alpine in the mountains . What is now California was first settled by various Native American tribes before being explored by a number of European expeditions during the 16th and 17th centuries . The Spanish Empire then claimed it as part of Alta California in their New Spain colony . The area became a part of Mexico in 1821 following its successful war for independence , but was ceded to the United States in 1848 after the Mexican -- American War . The western portion of Alta California then was organized as the State of California , and admitted as the 31st state on September 9 , 1850 . The California Gold Rush starting in 1848 led to dramatic social and demographic changes , with large-scale emigration from the east and abroad with an accompanying economic boom . If it were a country , California would be the 6th largest economy in the world and the 35th most populous . It is also regarded as a global trendsetter in both popular culture and politics , and is the origin of the film industry , the hippie counterculture , the Internet , and the personal computer , among others . Fifty-eight percent of the state 's economy is centered on finance , government , real estate services , technology , and professional , scientific and technical business services . The San Francisco Bay Area has the nation 's highest median household income by metropolitan area , and is the headquarters of three of the world 's largest 40 firms by revenue , Chevron , Apple , and McKesson . Although it accounts for only 1.5 percent of the state 's economy , California 's agriculture industry has the highest output of any U.S. state . |
840 | List_of_heat_waves | At four degrees, the deadly European heat wave of 2003, which killed as many as 2,000 people a day, will be a normal summer. | List of heat waves This is a partial list of significant heat waves , listed in order of occurrence . |
2942 | Greenhouse_gas | It's usually taken to be the fact that as carbon dioxide concentrations in the atmosphere increase, the 1 per cent of CO2 that's the heavier carbon isotope ratio c13 declines in proportion. | 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 . |
1824 | Greenhouse_gas | 94 percent of the carbon emissions which you so want to get rid of are caused by nature. | 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 . |
376 | Botany | whenever in the past there was an explosion of plant life, the carbon dioxide content was far higher than at present. | Botany Botany , also called plant science ( s ) , plant biology or phytology , is the science of plant life and a branch of biology . A botanist or plant scientist is a scientist who specialises in this field . The term `` botany '' comes from the Ancient Greek word βοτάνη ( botanē ) meaning `` pasture '' , `` grass '' , or `` fodder '' ; βοτάνη is in turn derived from βόσκειν ( boskein ) , `` to feed '' or `` to graze '' . Traditionally , botany has also included the study of fungi and algae by mycologists and phycologists respectively , with the study of these three groups of organisms remaining within the sphere of interest of the International Botanical Congress . Nowadays , botanists ( in the strict sense ) study approximately 410,000 species of land plants of which some 391,000 species are vascular plants ( including ca 369,000 species of flowering plants ) , and ca 20,000 are bryophytes . Botany originated in prehistory as herbalism with the efforts of early humans to identify -- and later cultivate -- edible , medicinal and poisonous plants , making it one of the oldest branches of science . Medieval physic gardens , often attached to monasteries , contained plants of medical importance . They were forerunners of the first botanical gardens attached to universities , founded from the 1540s onwards . One of the earliest was the Padua botanical garden . These gardens facilitated the academic study of plants . Efforts to catalogue and describe their collections were the beginnings of plant taxonomy , and led in 1753 to the binomial system of Carl Linnaeus that remains in use to this day . In the 19th and 20th centuries , new techniques were developed for the study of plants , including methods of optical microscopy and live cell imaging , electron microscopy , analysis of chromosome number , plant chemistry and the structure and function of enzymes and other proteins . In the last two decades of the 20th century , botanists exploited the techniques of molecular genetic analysis , including genomics and proteomics and DNA sequences to classify plants more accurately . Modern botany is a broad , multidisciplinary subject with inputs from most other areas of science and technology . Research topics include the study of plant structure , growth and differentiation , reproduction , biochemistry and primary metabolism , chemical products , development , diseases , evolutionary relationships , systematics , and plant taxonomy . Dominant themes in 21st century plant science are molecular genetics and epigenetics , which are the mechanisms and control of gene expression during differentiation of plant cells and tissues . Botanical research has diverse applications in providing staple foods , materials such as timber , oil , rubber , fibre and drugs , in modern horticulture , agriculture and forestry , plant propagation , breeding and genetic modification , in the synthesis of chemicals and raw materials for construction and energy production , in environmental management , and the maintenance of biodiversity . |
2907 | Climate_of_the_Arctic | Maximum warming occurs over the surface during winter while less surface warming is found in summer when heat is being used to melt sea ice. | Climate of the Arctic The climate of the Arctic is characterized by long , cold winters and short , cool summers . There is a large amount of variability in climate across the Arctic , but all regions experience extremes of solar radiation in both summer and winter . Some parts of the Arctic are covered by ice ( sea ice , glacial ice , or snow ) year-round , and nearly all parts of the Arctic experience long periods with some form of ice on the surface . Average January temperatures range from about − 34 ° C to 0 ° C ( − 40 to +32 ° F ) , and winter temperatures can drop below − 50 ° C ( − 58 ° F ) over large parts of the Arctic . Average July temperatures range from about − 10 to +10 ° C ( 14 to 50 ° F ) , with some land areas occasionally exceeding 30 ° C ( 86 ° F ) in summer . The Arctic consists of ocean that is largely surrounded by land . As such , the climate of much of the Arctic is moderated by the ocean water , which can never have a temperature below − 2 ° C ( 28 ° F ) . In winter , this relatively warm water , even though covered by the polar ice pack , keeps the North Pole from being the coldest place in the Northern Hemisphere , and it is also part of the reason that Antarctica is so much colder than the Arctic . In summer , the presence of the nearby water keeps coastal areas from warming as much as they might otherwise . |
275 | Ice_age | until temperature increases began to slow down after 1998 and remained relatively stable for a period of 15 years | 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 . |
1758 | Little_Ice_Age | Temperature errors in the Great Lakes region are not used in any global temperature records. | Little Ice Age The Little Ice Age ( LIA ) was a period of cooling that occurred after the Medieval Warm Period . Although it was not a true ice age , the term was introduced into scientific literature by François E. Matthes in 1939 . It has been conventionally defined as a period extending from the 16th to the 19th centuries , but some experts prefer an alternative timespan from about 1300 to about 1850 . Climatologists and historians working with local records no longer expect to agree on either the start or end dates of the period , which varied according to local conditions . The NASA Earth Observatory notes three particularly cold intervals : one beginning about 1650 , another about 1770 , and the last in 1850 , all separated by intervals of slight warming . The Intergovernmental Panel on Climate Change Third Assessment Report considered the timing and areas affected by the Little Ice Age suggested largely-independent regional climate changes rather than a globally-synchronous increased glaciation . At most , there was modest cooling of the Northern Hemisphere during the period . Several causes have been proposed : cyclical lows in solar radiation , heightened volcanic activity , changes in the ocean circulation , variations in Earth 's orbit and axial tilt ( orbital forcing ) , inherent variability in global climate , and decreases in the human population . |
1849 | Snowball_Earth | Australia has more solar coverage than any other continent. | Snowball Earth The Snowball Earth hypothesis proposes that Earth 's surface became entirely or nearly entirely frozen at least once , sometime earlier than 650 Mya ( million years ago ) . Proponents of the hypothesis argue that it best explains sedimentary deposits generally regarded as of glacial origin at tropical palaeolatitudes , and other enigmatic features in the geological record . Opponents of the hypothesis contest the implications of the geological evidence for global glaciation and the geophysical feasibility of an ice - or slush-covered ocean , and emphasize the difficulty of escaping an all-frozen condition . A number of unanswered questions remain , including whether the Earth was a full snowball , or a `` slushball '' with a thin equatorial band of open ( or seasonally open ) water . The snowball Earth episodes occurred before the sudden radiation of multicellular bioforms , known as the Cambrian explosion . The most recent snowball episode may have triggered the evolution of multicellularity . Another , much earlier and longer snowball episode , the Huronian glaciation , which occurred 2400 to 2100 Mya , may have been triggered by the first appearance of oxygen in the atmosphere , the `` Great Oxygenation Event . '' |
621 | Global_warming | Dr. Gutzler said spring temperatures have an impact, too, with warmer air causing more snow to turn to vapor and essentially disappear. | 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 . |
3079 | Climate_change_in_the_Arctic | This was the case last year too, while earlier years in the DMI analysis period (1958-2010) hardly ever shows Arctic melt season temperatures this cold (Frank Lansner) | 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 . |
142 | Global_warming | Worst-case global heating scenarios may need to be revised upwards in light of a better understanding of the role of clouds, scientists have said. | 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 . |
1917 | 20th_century | May 2018 marked the 401st straight month of global temperatures exceeding the 20th century average. | 20th century The 20th century was a century that began on January 1 , 1901 and ended on December 31 , 2000 . It was the tenth and final century of the 2nd millennium . It is distinct from the century known as the 1900s which began on January 1 , 1900 , and ended on December 31 , 1999 . The 20th century was dominated by a chain of events that heralded significant changes in world history as to redefine the era : World War I and World War II , nuclear power and space exploration , nationalism and decolonization , the Cold War and post-Cold War conflicts ; intergovernmental organizations and cultural homogenization through developments in emerging transportation and communications technology ; poverty reduction and world population growth , awareness of environmental degradation , ecological extinction ; and the birth of the Digital Revolution . It saw great advances in communication and medical technology that by the late 1980s allowed for near-instantaneous worldwide computer communication and genetic modification of life . The term `` short twentieth century '' was coined to represent the events from 1914 to 1991 . Global total fertility rates , sea level rise and ecological collapses increased ; the resulting competition for land and dwindling resources accelerated deforestation , water depletion . and the mass extinction of half the world 's estimated nine million unique species and wildlife population ; consequences which are now being dealt with . It took all of human history up to 1804 for the world 's population to reach 1 billion ; world population reached an estimated 2 billion in 1927 ; by late 1999 , the global population reached 6 billion . Global literacy averaged 80 % ; global lifespan-averages exceeded 40 + years for the first time in history , with over half achieving 70 + years ( three decades longer than it was a century ago ) . |
2152 | Greenhouse_effect | Venus doesn't have a runaway greenhouse effect | 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 . |
2181 | Little_Ice_Age | Humans survived past climate changes | Little Ice Age The Little Ice Age ( LIA ) was a period of cooling that occurred after the Medieval Warm Period . Although it was not a true ice age , the term was introduced into scientific literature by François E. Matthes in 1939 . It has been conventionally defined as a period extending from the 16th to the 19th centuries , but some experts prefer an alternative timespan from about 1300 to about 1850 . Climatologists and historians working with local records no longer expect to agree on either the start or end dates of the period , which varied according to local conditions . The NASA Earth Observatory notes three particularly cold intervals : one beginning about 1650 , another about 1770 , and the last in 1850 , all separated by intervals of slight warming . The Intergovernmental Panel on Climate Change Third Assessment Report considered the timing and areas affected by the Little Ice Age suggested largely-independent regional climate changes rather than a globally-synchronous increased glaciation . At most , there was modest cooling of the Northern Hemisphere during the period . Several causes have been proposed : cyclical lows in solar radiation , heightened volcanic activity , changes in the ocean circulation , variations in Earth 's orbit and axial tilt ( orbital forcing ) , inherent variability in global climate , and decreases in the human population . |
2862 | Climatic_Research_Unit_documents | The Independent Climate Change Email Review found the CRU scientists were unhelpful and unsympathetic to information requesters and at times broke FoI laws. | 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 . '' |
520 | Planetary_boundaries | Just 1.25 per cent of the carbon dioxide in the atmosphere-ocean system has been released by humans in the past 250 years. | Planetary boundaries Planetary boundaries is the central concept in an Earth system framework proposed by a group of Earth system and environmental scientists led by Johan Rockström from the Stockholm Resilience Centre and Will Steffen from the Australian National University . In 2009 , the group proposed a framework of `` planetary boundaries '' designed to define a `` safe operating space for humanity '' for the international community , including governments at all levels , international organizations , civil society , the scientific community and the private sector , as a precondition for sustainable development . This framework is based on scientific research that indicates that since the Industrial Revolution , human actions have gradually become the main driver of global environmental change . The scientists assert that once human activity has passed certain thresholds or tipping points , defined as `` planetary boundaries '' , there is a risk of `` irreversible and abrupt environmental change '' . The group identified nine Earth system processes which have boundaries that , to the extent that they are not crossed , mark the safe zone for the planet . However , because of human activities some of these dangerous boundaries have already been crossed , while others are in imminent danger of being crossed . Rockström and Steffen collaborated with 26 leading academics , including Nobel laureate Paul Crutzen , Goddard Institute for Space Studies climate scientist James Hansen and the German Chancellor 's chief climate adviser Hans Joachim Schellnhuber . The group identified nine `` planetary life support systems '' essential for human survival , and attempted to quantify just how far seven of these systems have been pushed already . They then estimated how much further we can go before our own survival is threatened ; beyond these boundaries there is a risk of `` irreversible and abrupt environmental change '' which could make Earth less habitable . Estimates indicate that three of these boundaries -- climate change , biodiversity loss , and the biogeochemical flow boundary -- appear to have been crossed . The boundaries are `` rough , first estimates only , surrounded by large uncertainties and knowledge gaps '' that interact in ways that are complex and not well understood . Boundaries can help identify where there is room and define a `` safe space for human development '' , which is an improvement on approaches which aim at just minimizing human impacts on the planet . The 2009 report was presented to the General Assembly of the Club of Rome in Amsterdam . An edited summary of the report was subsequently published as the featured article in a special edition of Nature . Nature also published critical commentary from leading academics they invited to comment on each of the seven planetary boundaries which had been quantified , including comments from Nobel laureate Mario J. Molina and biologist Cristián Samper . In 2015 , a second paper was published in Science updating the Planetary Boundaries concept . The findings were presented at the World Economic Forum in Davos , January 2015 . |
809 | Maryland | In the early 20th century, state and federal governments began aggressively fighting wildfires and trying to keep them as small as possible. | Maryland Maryland ( -LSB- ˈmɛrᵻlənd -RSB- ) is a state in the Mid-Atlantic region of the United States , bordering Virginia , West Virginia , and Washington , D.C. to its south and west ; Pennsylvania to its north ; and Delaware to its east . The state 's largest city is Baltimore , and its capital is Annapolis . Among its occasional nicknames are Old Line State , the Free State , and the Chesapeake Bay State . The state is named after Henrietta Maria of France , the wife of Charles I of England . One of the original Thirteen Colonies , Maryland is considered to be the birthplace of religious freedom in America , when it was formed by George Calvert in the early 17th century as an intended refuge for persecuted Catholics from England . George Calvert was the first Lord of Baltimore and the first English proprietor of the then-Maryland colonial grant . Maryland was the seventh state to ratify the United States Constitution , and played a pivotal role in the founding of Washington , D.C. , which was established on land donated by the state . Maryland is one of the smallest U.S. states in terms of area , as well as one of the most densely populated , with around six million residents . , Maryland had the highest median household income of any state , owing in large part to its close proximity to the nation 's capital and a highly diversified economy spanning manufacturing , services , and biotechnology . |
1866 | Global_issue | Climate scientists have predicted global temperatures would increase more than one degree Celsius by 2020," but observed temperatures have been only half as high. | Global issue Informally , a global issue describes any social , economic , political or environmental problem that affects the global community , possibly in a catastrophic way . Solution to global issues requires cooperation among nations . In their book Global Issues , Hite and Seitz emphasize that global issues are qualitatively different from international affairs and that the former arise from growing international interdependencies which makes the issues themselves interdependent . |
768 | Climate_change_denial | "We've known about [the greenhouse effect] for more than a century. | Climate change denial Climate change denial , or global warming denial , is part of the global warming controversy . It involves denial , dismissal , unwarranted doubt or contrarian views which strongly depart from the scientific opinion on climate change , including the extent to which it is caused by humans , its impacts on nature and human society , or the potential of adaptation to global warming by human actions . Some deniers do endorse the term , but others often prefer the term climate change skepticism , although this is a misnomer for those who deny anthropogenic global warming . In effect , the two terms form a continuous , overlapping range of views , and generally have the same characteristics : both reject , to a greater or lesser extent , mainstream scientific opinion on climate change . Climate change denial can also be implicit , when individuals or social groups accept the science but fail to come to terms with it or to translate their acceptance into action . Several social science studies have analyzed these positions as forms of denialism . Campaigning to undermine public trust in climate science has been described as a `` denial machine '' of industrial , political and ideological interests , supported by conservative media and skeptical bloggers in manufacturing uncertainty about global warming . In the public debate , phrases such as climate skepticism have frequently been used with the same meaning as climate denialism . The labels are contested : those actively challenging climate science commonly describe themselves as `` skeptics '' , but many do not comply with common standards of scientific skepticism and , regardless of evidence , persistently deny the validity of human caused global warming . Although scientific opinion on climate change is that human activity is extremely likely to be the primary driver of climate change , the politics of global warming have been affected by climate change denial , hindering efforts to prevent climate change and adapt to the warming climate . Those promoting denial commonly use rhetorical tactics to give the appearance of a scientific controversy where there is none . Of the world 's countries , the climate change denial industry is most powerful in the United States . Since January 2015 , the United States Senate Committee on Environment and Public Works has been chaired by oil lobbyist and climate change denier Jim Inhofe . Inhofe is notorious for having called climate change `` the greatest hoax ever perpetrated against the American people '' and for having claimed to have debunked the alleged hoax in February 2015 when he brought a snowball with him in the Senate chamber and tossed it across the floor . Organised campaigning to undermine public trust in climate science is associated with conservative economic policies and backed by industrial interests opposed to the regulation of emissions . Climate change denial has been associated with the fossil fuels lobby , the Koch brothers , industry advocates and libertarian think tanks , often in the United States . More than 90 % of papers sceptical on climate change originate from right-wing think tanks . The total annual income of these climate change counter-movement-organizations is roughly $ 900 million . Between 2002 and 2010 , nearly $ 120 million ( # 77 million ) was anonymously donated via the Donors Trust and Donors Capital Fund to more than 100 organisations seeking to undermine the public perception of the science on climate change . In 2013 the Center for Media and Democracy reported that the State Policy Network ( SPN ) , an umbrella group of 64 U.S. think tanks , had been lobbying on behalf of major corporations and conservative donors to oppose climate change regulation . Since the late 1970s , oil companies have published research broadly in line with the standard views on global warming . Despite this , oil companies organized a climate change denial campaign to disseminate public disinformation for several decades , a strategy that has been compared to the organized denial of the hazards of tobacco smoking by tobacco companies . |
363 | Climate_of_Asia | Monsoons in China fail, the great rivers of Asia virtually dry up, and rainfall in central America falls by half. | Climate of Asia The Climate of Asia is wet across southeast sections , and dry across much of the interior . Some of the largest daily temperature ranges on Earth occur in western sections of Asia . The monsoon circulation dominates across southern and eastern sections , due to the presence of the Himalayas forcing the formation of a thermal low which draws in moisture during the summer . Southwestern sections of the continent experience low relief as a result of the subtropical high pressure belt ; they are hot in the summer , warm to cool in winter , and may snow at higher altitudes . Siberia is one of the coldest places in the Northern Hemisphere , and can act as a source of arctic air masses for North America . The most active place on Earth for tropical cyclone activity lies northeast of the Philippines and south of Japan , and the phase of the El Niño-Southern Oscillation modulates where in Asia landfall is more likely to occur , |
3075 | Sea_level_rise | Multiple lines of evidence indicate Greenland's ice loss is accelerating and will contribute sea level rise in the order of metres over the next few centuries. | 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 . |
1829 | Effects_of_global_warming | "the cascading effects" of climate change contributed to the rise of ISIS. | Effects of global warming The effects of global warming are the environmental and social changes caused ( directly or indirectly ) by human emissions of greenhouse gases . There is a scientific consensus that climate change is occurring , and that human activities are the primary driver . Many impacts of climate change have already been observed , including glacier retreat , changes in the timing of seasonal events ( e.g. , earlier flowering of plants ) , and changes in agricultural productivity . Future effects of climate change will vary depending on climate change policies and social development . The two main policies to address climate change are reducing human greenhouse gas emissions ( climate change mitigation ) and adapting to the impacts of climate change . Geoengineering is another policy option . Near-term climate change policies could significantly affect long-term climate change impacts . Stringent mitigation policies might be able to limit global warming ( in 2100 ) to around 2 ° C or below , relative to pre-industrial levels . Without mitigation , increased energy demand and extensive use of fossil fuels might lead to global warming of around 4 ° C. Higher magnitudes of global warming would be more difficult to adapt to , and would increase the risk of negative impacts . |
1212 | Carbon_tax | (In technical lingo, the so-called social cost of carbon would be negative.)" | Carbon tax A carbon tax is a tax levied on the carbon content of fuels . It is a form of carbon pricing . Carbon is present in every hydrocarbon fuel ( coal , petroleum , and natural gas ) and converted to carbon dioxide and other products when combusted . In contrast , non-combustion energy sources -- wind , sunlight , geothermal , hydropower , and nuclear -- do not convert hydrocarbons to . is a heat-trapping `` greenhouse '' gas which represents a negative externality on the climate system ( see scientific opinion on global warming ) . Since GHG emissions caused by the combustion of fossil fuels are closely related to the carbon content of the respective fuels , a tax on these emissions can be levied by taxing the carbon content of fossil fuels at any point in the product cycle of the fuel . Carbon tax offers social and economic benefits . It is a tax that increases revenue without significantly altering the economy while simultaneously promoting objectives of climate change policy . The objective of a carbon tax is to reduce the harmful and unfavorable levels of carbon dioxide emissions , thereby decelerating climate change and its negative effects on the environment and human health . Carbon taxes offer a potentially cost-effective means of reducing greenhouse gas emissions . From an economic perspective , carbon taxes are a type of Pigovian tax . They help to address the problem of emitters of greenhouse gases not facing the full social cost of their actions . Carbon taxes can be a regressive tax , in that they may directly or indirectly affect low-income groups disproportionately . The regressive impact of carbon taxes could be addressed by using tax revenues to favour low-income groups . A number of countries have implemented carbon taxes or energy taxes that are related to carbon content . Most environmentally related taxes with implications for greenhouse gas emissions in OECD countries are levied on energy products and motor vehicles , rather than on emissions directly . Opposition to increased environmental regulation such as carbon taxes often centers on concerns that firms might relocate and/or people might lose their jobs . It has been argued , however , that carbon taxes are more efficient than direct regulation and may even lead to higher employment ( see footnotes ) . Many large users of carbon resources in electricity generation , such as the United States , Russia , and China , are resisting carbon taxation . |
1853 | Barack_Obama | Barack Obama supports proposals "to devote billions of dollars annually to state game and fish agencies and federal land management agencies to help them ensure that fish and wildlife survive the impacts of climate change." | Barack Obama Barack Hussein Obama II ( -LSB- bəˈrɑːk_huːˈseɪn_oʊˈbɑːmə -RSB- ; born August 4 , 1961 ) is an American politician who served as the 44th President of the United States from 2009 to 2017 . He is the first African American to have served as president . He previously served in the U.S. Senate representing Illinois from 2005 to 2008 , and in the Illinois State Senate from 1997 to 2004 . Obama was born in Honolulu , Hawaii , two years after the territory was admitted to the Union as the 50th state . Raised largely in Hawaii , Obama also spent one year of his childhood in Washington State and four years in Indonesia . After graduating from Columbia University in 1983 , he worked as a community organizer in Chicago . In 1988 Obama enrolled in Harvard Law School , where he was the first black president of the Harvard Law Review . After graduation , he became a civil rights attorney and professor , teaching constitutional law at the University of Chicago Law School from 1992 to 2004 . Obama represented the 13th District for three terms in the Illinois Senate from 1997 to 2004 , when he ran for the U.S. Senate . Obama received national attention in 2004 , with his unexpected March primary win , his well-received July Democratic National Convention keynote address , and his landslide November election to the Senate . In 2008 , Obama was nominated for president , a year after his campaign began , and after a close primary campaign against Hillary Clinton . He was elected over Republican John McCain , and was inaugurated on January 20 , 2009 . Nine months later , Obama was named the 2009 Nobel Peace Prize laureate . During his first two years in office , Obama signed many landmark bills . Main reforms were the Patient Protection and Affordable Care Act ( often referred to as `` Obamacare '' ) , the Dodd -- Frank Wall Street Reform and Consumer Protection Act , and the Do n't Ask , Do n't Tell Repeal Act of 2010 . The American Recovery and Reinvestment Act of 2009 and Tax Relief , Unemployment Insurance Reauthorization , and Job Creation Act of 2010 served as economic stimulus amidst the Great Recession , but the GOP regained control of the House of Representatives in 2011 . After a lengthy debate over the national debt limit , Obama signed the Budget Control and the American Taxpayer Relief Acts . In foreign policy , Obama increased U.S. troop levels in Afghanistan , reduced nuclear weapons with the U.S.-Russian New START treaty , and ended military involvement in the Iraq War . He ordered military involvement in Libya in opposition to Muammar Gaddafi , and the military operation that resulted in the death of Osama bin Laden . After winning re-election by defeating Republican nominee Mitt Romney , Obama was sworn in for a second term in 2013 . During his second term , Obama promoted greater inclusiveness for LGBT Americans , with his administration filing briefs that urged the Supreme Court to strike down same-sex marriage bans as unconstitutional ( United States v. Windsor and Obergefell v. Hodges ) . Obama also advocated gun control in response to the Sandy Hook Elementary School shooting , and issued wide-ranging executive actions concerning climate change and immigration . In foreign policy , Obama ordered military intervention in Iraq in response to gains made by ISIL after the 2011 withdrawal from Iraq , continued the process of ending U.S. combat operations in Afghanistan , promoted discussions that led to the 2015 Paris Agreement on global climate change , initiated the sanctions against Russia following the invasion in Ukraine , brokered a nuclear deal with Iran , and normalized U.S. relations with Cuba . Obama left office in January 2017 with a 60 % approval rating . He currently resides in Washington , D.C. His presidential library will be built in Chicago . |
1545 | Global_warming | Increasing CO2 in the atmosphere has little to no effect. | 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 . |
2004 | Hillary_Clinton | They (Clinton and Obama) have never to my knowledge been involved in legislation nor hearings nor engagement on this issue (climate change). | Hillary Clinton Hillary Diane Rodham Clinton ( -LSB- ˈhɪləri_daɪˈæn_ˈrɒdəm_ˈklɪntən -RSB- born October 26 , 1947 ) is an American politician who was the 67th United States Secretary of State from 2009 to 2013 , U.S. Senator from New York from 2001 to 2009 , First Lady of the United States from 1993 to 2001 , and the Democratic Party 's nominee for President of the United States in the 2016 election . Born in Chicago , Illinois , and raised in the Chicago suburb of Park Ridge , Clinton graduated from Wellesley College in 1969 , and earned a J.D. from Yale Law School in 1973 . After serving as a congressional legal counsel , she moved to Arkansas and married Bill Clinton in 1975 . In 1977 , she co-founded Arkansas Advocates for Children and Families . She was appointed the first female chair of the Legal Services Corporation in 1978 and became the first female partner at Rose Law Firm the following year . As First Lady of Arkansas , she led a task force whose recommendations helped reform Arkansas 's public schools . As First Lady of the United States , Clinton was an advocate for gender equality and healthcare reform . Her relationship with her husband came under public speculation during the Lewinsky scandal , forcing her to issue a statement reaffirming her commitment to the marriage . Clinton was elected in 2000 as the first female senator from New York . She was re-elected to the Senate in 2006 . Running for president in 2008 , she won far more delegates than any previous female candidate , but lost the Democratic nomination to Barack Obama . As Secretary of State in the Obama administration from 2009 to 2013 , Clinton responded to the Arab Spring , during which she advocated the U.S. military intervention in Libya . She helped organize a diplomatic isolation and international sanctions regime against Iran , in an effort to force curtailment of that country 's nuclear program ; this would eventually lead to the multinational Joint Comprehensive Plan of Action agreement in 2015 . Leaving office after Obama 's first term , she wrote her fifth book and undertook speaking engagements . Clinton made a second presidential run in 2016 . She received the most votes and primary delegates in the 2016 Democratic primaries , and formally accepted her party 's nomination for President of the United States on July 28 , 2016 with vice presidential running mate Senator Tim Kaine . She became the first female candidate to be nominated for president by a major U.S. political party . Despite winning a plurality of the national popular vote , Clinton lost the Electoral College and the presidency to her Republican opponent Donald Trump . Following her loss , in 2017 she decided to focus on being a self-described `` activist citizen '' . |
2262 | Hockey_stick_controversy | Since the hockey stick paper in 1998, there have been a number of proxy studies analysing a variety of different sources including corals, stalagmites, tree rings, boreholes and ice cores. | Hockey stick controversy In the hockey stick controversy , the data and methods used in reconstructions of the temperature record of the past 1000 years have been disputed . Reconstructions have consistently shown that the rise in the instrumental temperature record of the past 150 years is not matched in earlier centuries , and the name `` hockey stick graph '' was coined for figures showing a long-term decline followed by an abrupt rise in temperatures . These graphs were publicised to explain the scientific findings of climatology , and in addition to scientific debate over the reconstructions , they have been the topic of political dispute . The issue is part of the global warming controversy and has been one focus of political responses to reports by the Intergovernmental Panel on Climate Change ( IPCC ) . Arguments over the reconstructions have been taken up by fossil fuel industry funded lobbying groups attempting to cast doubt on climate science . The use of proxy indicators to get quantitative estimates of the temperature record of past centuries was developed from the 1990s onwards , and found indications that recent warming was exceptional . The reconstruction introduced the `` Composite Plus Scaling '' ( CPS ) method used by most later large-scale reconstructions , and its findings were disputed by Patrick Michaels at the United States House Committee on Science . In 1998 , Michael E. Mann , Raymond S. Bradley and Malcolm K. Hughes developed new statistical techniques to produce ( MBH98 ) , the first eigenvector-based climate field reconstruction ( CFR ) . This showed global patterns of annual surface temperature , and included a graph of average hemispheric temperatures back to 1400 . In ( MBH99 ) the methodology was extended back to 1000 . The term hockey stick was coined by the climatologist Jerry D. Mahlman , to describe the pattern this showed , envisaging a graph that is relatively flat to 1900 as forming an ice hockey stick 's `` shaft '' , followed by a sharp increase corresponding to the `` blade '' . A version of this graph was featured prominently in the 2001 IPCC Third Assessment Report ( TAR ) , along with four other reconstructions supporting the same conclusion . The graph was publicised , and became a focus of dispute for those opposed to the strengthening scientific consensus that late 20th-century warmth was exceptional . Those disputing the graph included Pat Michaels , the George C. Marshall Institute and Fred Singer . A paper by Willie Soon and Sallie Baliunas claiming greater medieval warmth was used by the Bush administration chief of staff Philip Cooney to justify altering the first Environmental Protection Agency Report on the Environment . The paper was quickly dismissed by scientists in the Soon and Baliunas controversy , but on July 28 , Republican Jim Inhofe spoke in the Senate citing it to claim `` that man-made global warming is the greatest hoax ever perpetrated on the American people '' . Later in 2003 , a paper by Steve McIntyre and Ross McKitrick disputing the data used in MBH98 paper was publicised by the George C. Marshall Institute and the Competitive Enterprise Institute . In 2004 , Hans von Storch published criticism of the statistical techniques as tending to underplay variations in earlier parts of the graph , though this was disputed and he later accepted that the effect was very small . In 2005 , McIntyre and McKitrick published criticisms of the principal component analysis methodology as used in MBH98 and MBH99 . The analysis therein was subsequently disputed by published papers , including and , which pointed to errors in the McIntyre and McKitrick methodology . In June 2005 , Rep. Joe Barton launched what Sherwood Boehlert , chairman of the House Science Committee , called a `` misguided and illegitimate investigation '' into the data , methods and personal information of Mann , Bradley and Hughes . At Boehlert 's request , a panel of scientists convened by the National Research Council was set up , which reported in 2006 , supporting Mann 's findings with some qualifications , including agreeing that there were some statistical failings but these had little effect on the result . Barton and U.S. Rep. Ed Whitfield requested Edward Wegman to set up a team of statisticians to investigate , and they supported McIntyre and McKitrick 's view that there were statistical failings , although they did not quantify whether there was any significant effect . They also produced an extensive network analysis which has been discredited by expert opinion and found to have issues of plagiarism . Arguments against the MBH studies were reintroduced as part of the Climatic Research Unit email controversy , but dismissed by eight independent investigations . More than two dozen reconstructions , using various statistical methods and combinations of proxy records , have supported the broad consensus shown in the original 1998 hockey-stick graph , with variations in how flat the pre-20th century `` shaft '' appears . The 2007 IPCC Fourth Assessment Report cited 14 reconstructions , 10 of which covered 1,000 years or longer , to support its strengthened conclusion that it was likely that Northern Hemisphere temperatures during the 20th century were the highest in at least the past 1,300 years . Over a dozen subsequent reconstructions , including Mann et al. 2008 and , have supported these general conclusions . |
1782 | Micronesia | Thousands of coral atolls have "drowned" when unable to grow fast enough to survive at sea level. | Micronesia Micronesia ( from μικρός , mikrós , `` small '' + νῆσος , nêsos , `` island '' ) is a subregion of Oceania , comprising thousands of small islands in the western Pacific Ocean . It has a shared cultural history with two other island regions , Polynesia to the east and Melanesia to the south . The region has a tropical marine climate , and is part of the Oceania ecozone . There are four main archipelagos along with numerous outlying islands . Micronesia is divided politically among several sovereign countries . One of these is the Federated States of Micronesia , which is often called `` Micronesia '' for short and is not to be confused with the overall region . The Micronesia region encompasses five sovereign , independent nations -- the Federated States of Micronesia , Palau , Kiribati , Marshall Islands , and Nauru -- as well as three U.S. territories in the northern part : Northern Mariana Islands , Guam , and Wake Island . Micronesia began to be settled several millennia ago , although there are competing theories about the origin and arrival of the first settlers . The earliest known contact with Europeans occurred in 1521 , when Ferdinand Magellan reached the Marianas . The coinage of the term `` Micronesia '' is usually attributed to Jules Dumont d'Urville 's usage in 1832 , however Domeny de Rienzi had used the term a year previously . |
141 | Greenpeace | Greenpeace didn't save the whales, switching from whale oil to petroleum and palm oil did | Greenpeace Greenpeace is a non-governmental environmental organization with offices in over 40 countries and with an international coordinating body in Amsterdam , the Netherlands . Founded by Canadian and US ex-pat environmental activists in 1971 , Greenpeace states its goal is to `` ensure the ability of the Earth to nurture life in all its diversity '' and focuses its campaigning on worldwide issues such as climate change , deforestation , overfishing , commercial whaling , genetic engineering , and anti-nuclear issues . It uses direct action , lobbying , research , and ecotage to achieve its goals . The global organization does not accept funding from governments , corporations , or political parties , relying on 2.9 million individual supporters and foundation grants . Greenpeace has a general consultative status with the United Nations Economic and Social Council and is a founding member of the INGO Accountability Charter ; an international non-governmental organization that intends to foster accountability and transparency of non-governmental organizations . Greenpeace is known for its direct actions and has been described as the most visible environmental organization in the world . Greenpeace has raised environmental issues to public knowledge , and influenced both the private and the public sector . Greenpeace has also been a source of controversy ; its motives and methods ( some of the latter being illegal ) have received criticism , including an open letter from more than 100 Nobel laureates urging Greenpeace to end its campaign against genetically modified organisms ( GMOs ) . The organization 's direct actions have sparked legal actions against Greenpeace activists , such as fines and suspended sentences for destroying a test plot of genetically modified wheat and damaging the Nazca Lines , a UN World Heritage site in Peru . |
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