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1243 | Global_warming | by that I mean the central Arctic will be ice-free. | 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 . |
1524 | Intergovernmental_Panel_on_Climate_Change | The IPCC (2013), USGCRP (2017), and USGCRP (2018) indicate that it is extremely likely that human influence has been the dominant cause of the observed warming since the mid-twentieth century. | Intergovernmental Panel on Climate Change The Intergovernmental Panel on Climate Change ( IPCC ) is a scientific and intergovernmental body under the auspices of the United Nations , set up at the request of member governments , dedicated to the task of providing the world with an objective , scientific view of climate change and its political and economic impacts . It was first established in 1988 by two United Nations organizations , the World Meteorological Organization ( WMO ) and the United Nations Environment Programme ( UNEP ) , and later endorsed by the United Nations General Assembly through Resolution 43/53 . Membership of the IPCC is open to all members of the WMO and UNEP . The IPCC produces reports that support the United Nations Framework Convention on Climate Change ( UNFCCC ) , which is the main international treaty on climate change . The ultimate objective of the UNFCCC is to `` stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic -LSB- i.e. , human-induced -RSB- interference with the climate system '' . IPCC reports cover `` the scientific , technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change , its potential impacts and options for adaptation and mitigation . '' The IPCC does not carry out its own original research , nor does it do the work of monitoring climate or related phenomena itself . The IPCC bases its assessment on the published literature , which includes peer-reviewed and non-peer-reviewed sources . Thousands of scientists and other experts contribute ( on a voluntary basis , without payment from the IPCC ) to writing and reviewing reports , which are then reviewed by governments . IPCC reports contain a `` Summary for Policymakers '' , which is subject to line-by-line approval by delegates from all participating governments . Typically this involves the governments of more than 120 countries . The IPCC provides an internationally accepted authority on climate change , producing reports which have the agreement of leading climate scientists and the consensus of participating governments . The 2007 Nobel Peace Prize was shared , in equal parts , between the IPCC and Al Gore . |
2818 | Doctor_of_Philosophy | The 30,000 scientists and science graduates listed on the OISM petition represent a tiny fraction (0.3%) of all science graduates. | Doctor of Philosophy A Doctor of Philosophy ( PhD , Ph.D. , or DPhil ; Latin Philosophiae Doctor ) is a type of doctoral degree awarded by universities in many countries . Ph.D. s are awarded for a wide range of programs in the sciences ( e.g. , biology , chemistry , physics , mathematics , etc. ) , engineering , and humanities ( e.g. , history , geography , literature , musicology , etc. ) , among others . The Ph.D. is a terminal degree in many fields . The completion of a Ph.D. is often a requirement for employment as a university professor , researcher , or scientist in many fields . A clear distinction is made between an `` earned doctorate '' , which is awarded for completion of a course of study and a thesis or dissertation , and an `` honorary doctorate '' , a title granted by a university to a successful or notable person who has not completed doctoral academic work or completed a dissertation at the university . Individuals with an earned doctorate can use the title of `` Doctor '' with their name and use the post-nominal letters `` Ph.D. '' , `` PhD '' or `` DPhil '' . The requirements to earn a Ph.D. degree vary considerably according to the country , institution , and time period , from entry-level research degrees to higher doctorates . A person who attains a doctorate of philosophy is automatically awarded the academic title of doctor . During the studies that lead to the degree , the student is called doctoral student or Ph.D. student , but also doctoral candidate or Ph.D. candidate once the student has completed all of the coursework and comprehensive examinations and is working on their thesis/dissertation ( all but dissertation ) . A student attaining this level may be granted a Candidate of Philosophy degree at some institutions . A Ph.D. candidate must submit a project , thesis or dissertation often consisting of a body of original academic research , which is in principle worthy of publication in a peer-reviewed journal . In many countries , a candidate must defend this work before a panel of expert examiners appointed by the university . Universities award other types of doctorates besides the Ph.D. , such as the Doctor of Musical Arts ( D.M.A. ) , a degree for music performers and the Doctor of Education ( Ed.D. ) , a degree for professional educators . In 2016 , ELIA ( European League of the Institutes of the Arts ) launched The ` Florence Principles ' on the Doctorate in the Arts . The Florence Principles relating to the Salzburg Principles and the Salzburg Recommendations of EUA ( European University Association ) name seven points of attention to specify the Doctorate / Ph.D. in the Arts compared to a scientific doctorate / Ph.D. . The Florence Principles have been endorsed are supported also by AEC , CILECT , CUMULUS and SAR . In the context of academic degrees , the term `` philosophy '' does not refer solely to the field or academic discipline of philosophy , but is used in a broader sense in accordance with its original Greek meaning , which is `` love of wisdom '' . In most of Europe , all fields ( history , philosophy , social sciences , mathematics , and natural philosophy/natural sciences ) other than theology , law , and medicine ( the so-called professional , vocational , or technical curriculum ) were traditionally known as philosophy , and in Germany and elsewhere in Europe the basic faculty of liberal arts was known as the `` faculty of philosophy '' . |
478 | Climate_change_mitigation | Protecting and restoring forests would reduce 18% of emissions by 2030 | Climate change mitigation Climate change mitigation consists of actions to limit the magnitude or rate of long-term climate change . Climate change mitigation generally involves reductions in human ( anthropogenic ) emissions of greenhouse gases ( GHGs ) . Mitigation may also be achieved by increasing the capacity of carbon sinks , e.g. , through reforestation . Mitigation policies can substantially reduce the risks associated with human-induced global warming . According to the IPCC 's 2014 assessment report , `` Mitigation is a public good ; climate change is a case of the ` tragedy of the commons . Effective climate change mitigation will not be achieved if each agent ( individual , institution or country ) acts independently in its own selfish interest ( see international cooperation and emissions trading ) , suggesting the need for collective action . Some adaptation actions , on the other hand , have characteristics of a private good as benefits of actions may accrue more directly to the individuals , regions , or countries that undertake them , at least in the short term . Nevertheless , financing such adaptive activities remains an issue , particularly for poor individuals and countries . '' Examples of mitigation include phasing out fossil fuels by switching to low-carbon energy sources , such as renewable and nuclear energy , and expanding forests and other `` sinks '' to remove greater amounts of carbon dioxide from the atmosphere . Energy efficiency may also play a role , for example , through improving the insulation of buildings . Another approach to climate change mitigation is climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) . The ultimate objective of the UNFCCC is to stabilize atmospheric concentrations of GHGs at a level that would prevent dangerous human interference of the climate system . Scientific analysis can provide information on the impacts of climate change , but deciding which impacts are dangerous requires value judgments . In 2010 , Parties to the UNFCCC agreed that future global warming should be limited to below 2.0 ° C ( 3.6 ° F ) relative to the pre-industrial level . With the Paris Agreement of 2015 this was confirmed , but was revised with a new target laying down `` parties will do the best '' to achieve warming below 1.5 ° C . The current trajectory of global greenhouse gas emissions does not appear to be consistent with limiting global warming to below 1.5 or 2 ° C . Other mitigation policies have been proposed , some of which are more stringent or modest than the 2 ° C limit . |
645 | Nitrogen | Scientists just discovered a massive, heretofore unknown, source of nitrogen | Nitrogen Nitrogen is a chemical element with symbol N and atomic number 7 . It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772 . Although Carl Wilhelm Scheele and Henry Cavendish had independently done so at about the same time , Rutherford is generally accorded the credit because his work was published first . The name nitrogen was suggested by Jean-Antoine-Claude Chaptal in 1790 , when it was found that nitrogen was present in nitric acid and nitrates ; this name derives from the Greek roots νἰτρον `` nitre '' and - γεννᾶν `` to form '' . Antoine Lavoisier suggested instead the name azote , from the Greek άζωτικός `` no life '' , as it is an asphyxiant gas ; his name is instead used in many languages , such as French , Russian , and Turkish , and appears in the English names of some nitrogen compounds such as hydrazine , azides and azo compounds . Nitrogen is the lightest member of group 15 of the periodic table , often called the pnictogens . The name comes from the Greek πνίγειν `` to choke '' , directly referencing nitrogen 's asphyxiating properties . It is a common element in the universe , estimated at about seventh in total abundance in the Milky Way and the Solar System . At standard temperature and pressure , two atoms of the element bind to form dinitrogen , a colourless and odorless diatomic gas with the formula N2 . Dinitrogen forms about 78 % of Earth 's atmosphere , making it the most abundant uncombined element . Nitrogen occurs in all organisms , primarily in amino acids ( and thus proteins ) , in the nucleic acids ( DNA and RNA ) and in the energy transfer molecule adenosine triphosphate . The human body contains about 3 % nitrogen by mass , the fourth most abundant element in the body after oxygen , carbon , and hydrogen . The nitrogen cycle describes movement of the element from the air , into the biosphere and organic compounds , then back into the atmosphere . Many industrially important compounds , such as ammonia , nitric acid , organic nitrates ( propellants and explosives ) , and cyanides , contain nitrogen . The extremely strong triple bond in elemental nitrogen ( N ≡ N ) , the second strongest bond in any diatomic molecule , dominates nitrogen chemistry . This causes difficulty for both organisms and industry in converting N2 into useful compounds , but at the same time means that burning , exploding , or decomposing nitrogen compounds to form nitrogen gas releases large amounts of often useful energy . Synthetically produced ammonia and nitrates are key industrial fertilisers , and fertiliser nitrates are key pollutants in the eutrophication of water systems . Apart from its use in fertilisers and energy-stores , nitrogen is a constituent of organic compounds as diverse as Kevlar used in high-strength fabric and cyanoacrylate used in superglue . Nitrogen is a constituent of every major pharmacological drug class , including antibiotics . Many drugs are mimics or prodrugs of natural nitrogen-containing signal molecules : for example , the organic nitrates nitroglycerin and nitroprusside control blood pressure by metabolizing into nitric oxide . Many notable nitrogen-containing drugs , such as the natural caffeine and morphine or the synthetic amphetamines , act on receptors of animal neurotransmitters . |
2428 | Greenhouse_gas | It was the post war industrialization that caused the rapid rise in global CO2 emissions, but by 1945 when this began, the Earth was already in a cooling phase that started around 1942 and continued until 1975. | 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 . |
2048 | Fossil_fuel | CO2 is a greenhouse gas but is clearly subordinate to water vapour and other more significant factors determining global climate. | Fossil fuel Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms , containing energy originating in ancient photosynthesis . The age of the organisms and their resulting fossil fuels is typically millions of years , and sometimes exceeds 650 million years . Fossil fuels contain high percentages of carbon and include petroleum , coal , and natural gas . Other commonly used derivatives include kerosene and propane . Fossil fuels range from volatile materials with low carbon to hydrogen ratios like methane , to liquids like petroleum , to nonvolatile materials composed of almost pure carbon , like anthracite coal . Methane can be found in hydrocarbon fields either alone , associated with oil , or in the form of methane clathrates . The theory that fossil fuels formed from the fossilized remains of dead plants by exposure to heat and pressure in the Earth 's crust over millions of years was first introduced by Georgius Agricola in 1556 and later by Mikhail Lomonosov in the 18th century . The Energy Information Administration estimates that in 2007 the primary sources of energy consisted of petroleum 36.0 % , coal 27.4 % , natural gas 23.0 % , amounting to an 86.4 % share for fossil fuels in primary energy consumption in the world . Non-fossil sources in 2006 included nuclear 8.5 % , hydroelectric 6.3 % , and others ( geothermal , solar , tidal , wind , wood , waste ) amounting to 0.9 % . World energy consumption was growing about 2.3 % per year . Although fossil fuels are continually being formed via natural processes , they are generally considered to be non-renewable resources because they take millions of years to form and the known viable reserves are being depleted much faster than new ones are being made . The use of fossil fuels raises serious environmental concerns . The burning of fossil fuels produces around 21.3 billion tonnes ( 21.3 gigatonnes ) of carbon dioxide ( CO2 ) per year . It is estimated that natural processes can only absorb about half of that amount , so there is a net increase of 10.65 billion tonnes of atmospheric carbon dioxide per year . Carbon dioxide is a greenhouse gas that increases radiative forcing and contributes to global warming . A global movement towards the generation of renewable energy is underway to help reduce global greenhouse gas emissions . |
559 | Scientific_consensus_on_climate_change | And there is a lot of evidence that climate change is diminishing biodiversity, which can be seen in these alpine meadows as well. | 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. |
1653 | Global_warming | The most recent ocean measurements show consistent 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 . |
3024 | Climate_change_feedback | Unlike the simple example of positive feedback we learned in high school, the increase from every round of feedback gets smaller and smaller, in the case of the enhanced greenhouse effect. | Climate change feedback Climate change feedback is important in the understanding of global warming because feedback processes may amplify or diminish the effect of each climate forcing , and so play an important part in determining the climate sensitivity and future climate state . Feedback in general is the process in which changing one quantity changes a second quantity , and the change in the second quantity in turn changes the first . Positive feedback amplifies the change in the first quantity while negative feedback reduces it . The term `` forcing '' means a change which may `` push '' the climate system in the direction of warming or cooling . An example of a climate forcing is increased atmospheric concentrations of greenhouse gases . By definition , forcings are external to the climate system while feedbacks are internal ; in essence , feedbacks represent the internal processes of the system . Some feedbacks may act in relative isolation to the rest of the climate system ; others may be tightly coupled ; hence it may be difficult to tell just how much a particular process contributes . Forcings , feedbacks and the dynamics of the climate system determine how much and how fast the climate changes . The main positive feedback in global warming is the tendency of warming to increase the amount of water vapor in the atmosphere , which in turn leads to further warming . The main negative feedback comes from the Stefan -- Boltzmann law , the amount of heat radiated from the Earth into space changes with the fourth power of the temperature of Earth 's surface and atmosphere . Some observed and potential effects of global warming are positive feedbacks , which contribute directly to further global warming . The Intergovernmental Panel on Climate Change 's ( IPCC ) Fourth Assessment Report states that `` Anthropogenic warming could lead to some effects that are abrupt or irreversible , depending upon the rate and magnitude of the climate change . '' |
724 | Global_warming | A fast transition away from fossil fuels in the next few decades could be enough to put off rapid sea-level rise for centuries. | 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 . |
404 | Global_warming | Actual weather records over the past 100 years show no correlation between rising carbon dioxide levels and local temperatures. | 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 . |
1343 | Effects_of_global_warming | roughly three-quarters of the tidal flood days now occurring in towns along the East Coast would not be happening in the absence of the rise in the sea level caused by human emissions. | 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 . |
1343 | Sea_level_rise | roughly three-quarters of the tidal flood days now occurring in towns along the East Coast would not be happening in the absence of the rise in the sea level caused by human emissions. | 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 . |
576 | University_of_Oxford | 'Summers keep getting hotter,' said Friederike Otto of the University of Oxford, who conducted extensive research into data from the heatwave that spread Europe in June, July and August 2017. | University of Oxford The University of Oxford ( informally Oxford University or simply Oxford ) is a collegiate research university located in Oxford , England . It has no known date of foundation , but there is evidence of teaching as far back as 1096 , making it the oldest university in the English-speaking world and the world 's second-oldest university in continuous operation . It is one of the world 's most prestigious universities . It grew rapidly from 1167 when Henry II banned English students from attending the University of Paris . After disputes between students and Oxford townsfolk in 1209 , some academics fled north-east to Cambridge where they established what became the University of Cambridge . The two `` ancient universities '' are frequently jointly referred to as `` Oxbridge '' . The university is made up of a variety of institutions , including 38 constituent colleges and a full range of academic departments which are organised into four divisions . All the colleges are self-governing institutions within the university , each controlling its own membership and with its own internal structure and activities . Being a city university , it does not have a main campus ; instead , its buildings and facilities are scattered throughout the city centre . Most undergraduate teaching at Oxford is organised around weekly tutorials at the colleges and halls , supported by classes , lectures and laboratory work provided by university faculties and departments . Oxford is the home of the Rhodes Scholarship , one of the world 's oldest and most prestigious scholarships , which has brought graduate students to study at the university for more than a century . The university operates the world 's oldest university museum , as well as the largest university press in the world and the largest academic library system in Britain . Oxford has educated many notable alumni , including 28 Nobel laureates , 27 Prime Ministers of the United Kingdom , and many heads of state and government around the world . |
41 | Scientific_consensus_on_climate_change | More than 500 scientists and professionals in climate and related fields have sent a 'European Climate Declaration' to the Secretary-General of the United Nations | 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. |
451 | Coal | The idea that the much smaller carbon dioxide cycle is now controlling the water cycle is not very likely. | Coal Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams . The harder forms , such as anthracite coal , can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure . Coal is composed primarily of carbon , along with variable quantities of other elements , chiefly hydrogen , sulfur , oxygen , and nitrogen . A fossil fuel , coal forms when dead plant matter is converted into peat , which in turn is converted into lignite , then sub-bituminous coal , after that bituminous coal , and lastly anthracite . This involves biological and geological processes that take place over time . Throughout human history , coal has been used as an energy resource , primarily burned for the production of electricity and heat , and is also used for industrial purposes , such as refining metals . Coal is the largest source of energy for the generation of electricity worldwide , as well as one of the largest worldwide anthropogenic sources of carbon dioxide releases . The extraction of coal , its use in energy production and its byproducts are all associated with environmental and health effects including climate change . Coal is extracted from the ground by coal mining . Since 1983 , the world 's top coal producer has been China . In 2015 China produced 3,747 million tonnes of coal -- 47.7 % of 7,861 million tonnes world coal production . In 2015 other large producers were United States ( 813 million tonnes ) , India ( 678 ) , European Union ( 539 ) and Australia ( 503 ) . In 2010 the largest exporters were Australia with 328 million tonnes ( 27.1 % of world coal export ) and Indonesia with 316 million tonnes ( 26.1 % ) , while the largest importers were Japan with 207 million tonnes ( 17.5 % of world coal import ) , China with 195 million tonnes ( 16.6 % ) and South Korea with 126 million tonnes ( 10.7 % ) . |
1714 | Christopher_Monckton,_3rd_Viscount_Monckton_of_Brenchley | Monckton used the IPCC equation in an inappropriate manner. | Christopher Monckton, 3rd Viscount Monckton of Brenchley Christopher Walter Monckton , 3rd Viscount Monckton of Brenchley ( born 14 February 1952 ) is a British public speaker and hereditary peer . He is known for his work as a journalist , Conservative political advisor , UKIP political candidate , and for his invention of the mathematical puzzle Eternity . Early on in his public speaking career topics centred on his mathematical puzzle and conservative politics . In recent years his public speaking has garnered attention due to his advocacy of climate change denial and his views on the European Union and social policy . |
109 | Sea_level | Local and regional sea levels continue to exhibit typical natural variability—in some places rising and in others falling. | 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 ) . |
2401 | Earth | Mother Earth has clearly ruled that CO2 is not a pollutant.' | 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 . |
614 | Temperate_climate | The Rio Grande is a classic "feast or famine" river, with a dry year or two typically followed by a couple of wet years that allow for recovery. | Temperate climate In geography , temperate or tepid latitudes of Earth lie between the tropics and the polar regions . The temperatures in these regions are generally relatively moderate , rather than extremely hot or cold , and the changes between summer and winter are also usually moderate . |
995 | Pacific_Ocean | "The Northern Hemisphere jet stream […] flow is stronger when that temperature difference is large. | Pacific Ocean The Pacific Ocean is the largest and deepest of the Earth 's oceanic divisions . It extends from the Arctic Ocean in the north to the Southern Ocean ( or , depending on definition , to Antarctica ) in the south and is bounded by Asia and Australia in the west and the Americas in the east . At 63,800,000 sqmi in area , this largest division of the World Ocean -- and , in turn , the hydrosphere -- covers about 46 % of the Earth 's water surface and about one-third of its total surface area , making it larger than all of the Earth 's land area combined . The equator subdivides it into the North Pacific Ocean and South Pacific Ocean , with two exceptions : the Galápagos and Gilbert Islands , while straddling the equator , are deemed wholly within the South Pacific . The Mariana Trench in the western North Pacific is the deepest point in the world , reaching a depth of 35797 ft. Both the center of the Water Hemisphere and the Western Hemisphere are in the Pacific Ocean . Though the peoples of Asia and Oceania have traveled the Pacific Ocean since prehistoric times , the eastern Pacific was first sighted by Europeans in the early 16th century when Spanish explorer Vasco Núñez de Balboa crossed the Isthmus of Panama in 1513 and discovered the great `` southern sea '' which he named Mar del Sur ( in Spanish ) . The ocean 's current name was coined by Portuguese explorer Ferdinand Magellan during the Spanish circumnavigation of the world in 1521 , as he encountered favorable winds on reaching the ocean . He called it Mar Pacífico , which in both Portuguese and Spanish means `` peaceful sea '' . |
2856 | Meteorology | At present, climate forecasts even as little as six weeks ahead can be diametrically the opposite of what actually occurs, even if the forecasts are limited to a small region of the planet.' | Meteorology Meteorology is a branch of the atmospheric sciences which includes atmospheric chemistry and atmospheric physics , with a major focus on weather forecasting . The study of meteorology dates back millennia , though significant progress in meteorology did not occur until the 18th century . The 19th century saw modest progress in the field after weather observation networks were formed across broad regions . Prior attempts at prediction of weather depended on historical data . It was n't until after the elucidation of the laws of physics and , more particularly , the development of the computer , allowing for the automated solution of a great many equations that model the weather , in the latter half of the 20th century that significant breakthroughs in weather forecasting were achieved . Meteorological phenomena are observable weather events that are explained by the science of meteorology . Meteorological phenomena are described and quantified by the variables of Earth 's atmosphere : temperature , air pressure , water vapor , mass flow , and the variations and interactions of those variables , and how they change over time . Different spatial scales are used to describe and predict weather on local , regional , and global levels . Meteorology , climatology , atmospheric physics , and atmospheric chemistry are sub-disciplines of the atmospheric sciences . Meteorology and hydrology compose the interdisciplinary field of hydrometeorology . The interactions between Earth 's atmosphere and its oceans are part of a coupled ocean-atmosphere system . Meteorology has application in many diverse fields such as the military , energy production , transport , agriculture , and construction . The word `` meteorology '' is from Greek μετέωρος metéōros `` lofty ; high ( in the sky ) '' ( from μετα - meta - `` above '' and ἀείρω aeiro `` I lift up '' ) and - λογία - logia '' - logy '' , i.e. `` the study of things in the air '' . |
2461 | 20th_century | Early 20th century warming was in large part due to rising solar activity and relatively quiet volcanic activity. | 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 ) . |
1689 | Evidence | Evidence is building that net cloud feedback is likely positive and unlikely to be strongly negative. | Evidence Evidence , broadly construed , is anything presented in support of an assertion . This support may be strong or weak . The strongest type of evidence is that which provides direct proof of the truth of an assertion . At the other extreme is evidence that is merely consistent with an assertion but does not rule out other , contradictory assertions , as in circumstantial evidence . In law , rules of evidence govern the types of evidence that are admissible in a legal proceeding . Types of legal evidence include testimony , documentary evidence , and physical evidence . The parts of a legal case which are not in controversy are known , in general , as the `` facts of the case . '' Beyond any facts that are undisputed , a judge or jury is usually tasked with being a trier of fact for the other issues of a case . Evidence and rules are used to decide questions of fact that are disputed , some of which may be determined by the legal burden of proof relevant to the case . Evidence in certain cases ( e.g. capital crimes ) must be more compelling than in other situations ( e.g. minor civil disputes ) , which drastically affects the quality and quantity of evidence necessary to decide a case . Scientific evidence consists of observations and experimental results that serve to support , refute , or modify a scientific hypothesis or theory , when collected and interpreted in accordance with the scientific method . In philosophy , the study of evidence is closely tied to epistemology , which considers the nature of knowledge and how it can be acquired . |
82 | Carbon_dioxide | The atmospheric residency time of carbon dioxide is five years | 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 . |
1146 | Global_warming | "It's far too early to tell if what we are seeing in the Arctic, and now the Antarctic, is a sharp shift towards warmer poles with less ice. | 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 . |
1790 | Kyoto_Protocol | Study finds low probability of both very low and very high climate sensitivities, and its lower estimate (as compared to the IPCC) is based on a new temperature reconstruction of the Last Glacial Maximum that may or may not withstand the test of time. | 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 . |
1411 | City | "Even if you could calculate some sort of meaningful global temperature statistic, the figure would be unimportant. | City A city is a large and permanent human settlement . Although there is no agreement on how a city is distinguished from a town in general English language meanings , many cities have special administrative , legal , or historical status based on local law . Cities generally have complex systems for sanitation , utilities , land usage , housing , and transportation . The concentration of development greatly facilitates interaction between people and businesses , sometimes benefiting both parties in the process , but it also presents challenges to managing urban growth . A big city or metropolis usually has associated suburbs and exurbs . Such cities are usually associated with metropolitan areas and urban areas , creating numerous business commuters traveling to urban centers for employment . Once a city expands far enough to reach another city , this region can be deemed a conurbation or megalopolis . Damascus is arguably the oldest city in the world . In terms of population , the largest city proper is Shanghai , while the fastest-growing is Dubai . |
1508 | Global_warming | global warming ceased around the end of the twentieth century and was followed (since 1997) by 19 years of stable temperature. | 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 . |
2668 | Chicago | Meanwhile, it will likely to continue to snow in Chicago in the coming days. | Chicago Chicago ( -LSB- ʃᵻˈkɑːɡoʊ -RSB- or -LSB- ʃᵻˈkɔːɡoʊ -RSB- ) , officially the City of Chicago , is the third-most populous city in the United States . With over 2.7 million residents , it is also the most populous city in both the state of Illinois and the Midwestern United States . It is the county seat of Cook County . The Chicago metropolitan area , often referred to as Chicagoland , has nearly 10 million people and is the third-largest in the U.S. Chicago has been called a global architecture capital . In terms of wealth and economy , Chicago is considered one of the most important business centers in the world . Chicago was incorporated as a city in 1837 , near a portage between the Great Lakes and the Mississippi River watershed , and grew rapidly in the mid-nineteenth century . Positioned along Lake Michigan , the city is an international hub for finance , commerce , industry , technology , telecommunications , and transportation : O'Hare International Airport is the second-busiest airport in the world when measured by aircraft traffic ; the region also has the largest number of U.S. highways and rail road freight . In 2012 , Chicago was listed as an alpha global city by the Globalization and World Cities Research Network , and ranked seventh in the world in the 2016 Global Cities Index . Chicago has the third-largest gross metropolitan product in the United States -- about $ 640 billion according to 2015 estimates . The city has one of the world 's largest and most diversified economies with no single industry employing more than 14 % of the workforce . In 2016 , Chicago hosted over 54 million domestic and international visitors , a new record making it one of the top visited cities in the nation . Landmarks in the city include Millennium Park , Navy Pier , the Magnificent Mile , Art Institute of Chicago , Museum Campus , the Willis ( Sears ) Tower , Museum of Science and Industry , and Lincoln Park Zoo . Chicago 's culture includes the visual arts , novels , film , theater , especially improvisational comedy , and music , particularly jazz , blues , soul , hip hop , gospel and house music . There are many colleges and universities in the Chicago area ; among these , Northwestern University , University of Chicago , and the University of Illinois at Chicago are classified as `` highest research '' doctoral universities . Additionally , Chicago has professional sports teams in each of the major professional leagues . The city has many nicknames , the best-known being the Windy City . |
2406 | Carbon_dioxide | This growth stimulation occurs because CO2 is one of the two raw materials (the other being water) that are required for photosynthesis. | 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 . |
1327 | Texas | Migration patterns show people heading for warm states like Texas and Florida, not snowy Minnesota and Michigan." | Texas Texas ( -LSB- ˈtɛksəs -RSB- , -LSB- localˈtɛksᵻz -RSB- Texas or Tejas -LSB- ˈtexas -RSB- ) is the second largest state in the United States by both area and population . Geographically located in the South Central region of the country , Texas shares borders with the U.S. states of Louisiana to the east , Arkansas to the northeast , Oklahoma to the north , New Mexico to the west , and the Mexican states of Chihuahua , Coahuila , Nuevo León , and Tamaulipas to the southwest , while the Gulf of Mexico is to the southeast . Houston is the most populous city in Texas and the fourth largest in the U.S. , while San Antonio is the second most populous in the state and seventh largest in the U.S. Dallas -- Fort Worth and Greater Houston are the fourth and fifth largest metropolitan statistical areas in the country , respectively . Other major cities include Austin , the second most populous state capital in the U.S. , and El Paso . Texas is nicknamed `` The Lone Star State '' to signify its former status as an independent republic , and as a reminder of the state 's struggle for independence from Mexico . The `` Lone Star '' can be found on the Texan state flag and on the Texan state seal . The origin of Texas 's name is from the word `` Tejas , '' which means `` friends '' in the Caddo language . Due to its size and geologic features such as the Balcones Fault , Texas contains diverse landscapes that resemble both the U.S. Southern and Southwestern regions . Although Texas is popularly associated with the U.S. southwestern deserts , less than 10 % of Texas ' land area is desert . Most of the population centers are located in areas of former prairies , grasslands , forests , and the coastline . Traveling from east to west , one can observe terrain that ranges from coastal swamps and piney woods , to rolling plains and rugged hills , and finally the desert and mountains of the Big Bend . The term `` six flags over Texas `` For example , as used by the large Grand Prairie -- based national and international amusement park operator Six Flags refers to several nations that have ruled over the territory . Spain was the first European country to claim the area of Texas . France held a short-lived colony . Mexico controlled the territory until 1836 when Texas won its independence , becoming an independent Republic . In 1845 , Texas joined the union as the 28th state . The state 's annexation set off a chain of events that led to the Mexican -- American War in 1846 . A slave state before the American Civil War , Texas declared its secession from the U.S. in early 1861 , and officially joined the Confederate States of America on March 2 of the same year . After the Civil War and the restoration of its representation in the federal government , Texas entered a long period of economic stagnation . One Texan industry that thrived after the Civil War was cattle . Due to its long history as a center of the industry , Texas is associated with the image of the cowboy . The state 's economic fortunes changed in the early 20th century , when oil discoveries initiated an economic boom in the state . With strong investments in universities , Texas developed a diversified economy and high tech industry in the mid-20th century . As of 2015 , it is second on the list of the most Fortune 500 companies with 54 . With a growing base of industry , the state leads in many industries , including agriculture , petrochemicals , energy , computers and electronics , aerospace , and biomedical sciences . Texas has led the nation in export revenue since 2002 and has the second-highest gross state product . |
1156 | Environmental_economics | The costs of emissions regulations, which will be paid by everyone, will be punishingly high and will provide no benefits to most people anywhere in the world. | Environmental economics Environmental economics is a sub-field of economics that is concerned with environmental issues . Quoting from the National Bureau of Economic Research Environmental Economics program : -LSB- ... -RSB- Environmental Economics -LSB- ... -RSB- undertakes theoretical or empirical studies of the economic effects of national or local environmental policies around the world -LSB- ... -RSB- . Particular issues include the costs and benefits of alternative environmental policies to deal with air pollution , water quality , toxic substances , solid waste , and global warming . Environmental economics is distinguished from ecological economics in that ecological economics emphasizes the economy as a subsystem of the ecosystem with its focus upon preserving natural capital . One survey of German economists found that ecological and environmental economics are different schools of economic thought , with ecological economists emphasizing `` strong '' sustainability and rejecting the proposition that natural capital can be substituted by human-made capital . |
1331 | Ocean | More than half of the 44 studies selected for publication found that raised levels of CO2 had little or no impact on marine life, including crabs, limpets, sea urchins and sponges | Ocean An ocean ( , the sea of classical antiquity ) is a body of saline water that composes much of a planet 's hydrosphere . On Earth , an ocean is one of the major conventional divisions of the World Ocean , which covers almost 71 % of its surface . These are , in descending order by area , the Pacific , Atlantic , Indian , Southern ( Antarctic ) , and Arctic Oceans . The word sea is often used interchangeably with `` ocean '' in American English but , strictly speaking , a sea is a body of saline water ( generally a division of the world ocean ) partly or fully enclosed by land . Saline water covers approximately 72 % of the planet 's surface ( ~ 3.6 km2 ) and is customarily divided into several principal oceans and smaller seas , with the ocean covering approximately 71 % of Earth 's surface and 90 % of the Earth 's biosphere . The ocean contains 97 % of Earth 's water , and oceanographers have stated that less than 5 % of the World Ocean has been explored . The total volume is approximately 1.35 billion cubic kilometers ( 320 million cu mi ) with an average depth of nearly 3700 m. As the world ocean is the principal component of Earth 's hydrosphere , it is integral to all known life , forms part of the carbon cycle , and influences climate and weather patterns . The world ocean is the habitat of 230,000 known species , but because much of it is unexplored , the number of species that exist is much larger , possibly over two million . The origin of Earth 's oceans remains unknown ; oceans are thought to have formed in the Hadean period and may have been the impetus for the emergence of life . Extraterrestrial oceans may be composed of water or other elements and compounds . The only confirmed large stable bodies of extraterrestrial surface liquids are the lakes of Titan , although there is evidence for the existence of oceans elsewhere in the Solar System . Early in their geologic histories , Mars and Venus are theorized to have had large water oceans . The Mars ocean hypothesis suggests that nearly a third of the surface of Mars was once covered by water , and a runaway greenhouse effect may have boiled away the global ocean of Venus . Compounds such as salts and ammonia dissolved in water lower its freezing point so that water might exist in large quantities in extraterrestrial environments as brine or convecting ice . Unconfirmed oceans are speculated beneath the surface of many dwarf planets and natural satellites ; notably , the ocean of Europa is estimated to have over twice the water volume of Earth . The Solar System 's giant planets are also thought to have liquid atmospheric layers of yet to be confirmed compositions . Oceans may also exist on exoplanets and exomoons , including surface oceans of liquid water within a circumstellar habitable zone . Ocean planets are a hypothetical type of planet with a surface completely covered with liquid . |
87 | Global_warming_controversy | NOAA has adjusted past temperatures to look colder than they were and recent temperatures to look warmer than they were. | Global warming controversy The global warming controversy concerns the public debate over whether global warming is occurring , how much has occurred in modern times , what has caused it , what its effects will be , whether any action should be taken to curb it , and if so what that action should be . In the scientific literature , there is a strong consensus that global surface temperatures have increased in recent decades and that the trend is caused by human-induced emissions of greenhouse gases . No scientific body of national or international standing disagrees with this view , though a few organizations with members in extractive industries hold non-committal positions . Disputes over the key scientific facts of global warming are more prevalent in the media than in the scientific literature , where such issues are treated as resolved , and such disputes are more prevalent in the United States than globally . Political and popular debate concerning the existence and cause of climate change includes the reasons for the increase seen in the instrumental temperature record , whether the warming trend exceeds normal climatic variations , and whether human activities have contributed significantly to it . Scientists have resolved these questions decisively in favour of the view that the current warming trend exists and is ongoing , that human activity is the cause , and that it is without precedent in at least 2000 years . Public disputes that also reflect scientific debate include estimates of how responsive the climate system might be to any given level of greenhouse gases ( climate sensitivity ) , how global climate change will play out at local and regional scales , and what the consequences of global warming will be . Global warming remains an issue of widespread political debate , often split along party political lines , especially in the United States . Many of the issues that are settled within the scientific community , such as human responsibility for global warming , remain the subject of politically or economically motivated attempts to downplay , dismiss or deny them -- an ideological phenomenon categorised by academics and scientists as climate change denial . The sources of funding for those involved with climate science -- both supporting and opposing mainstream scientific positions -- have been questioned by both sides . There are debates about the best policy responses to the science , their cost-effectiveness and their urgency . Climate scientists , especially in the United States , have reported official and oil-industry pressure to censor or suppress their work and hide scientific data , with directives not to discuss the subject in public communications . Legal cases regarding global warming , its effects , and measures to reduce it have reached American courts . The fossil fuels lobby has been identified as overtly or covertly supporting efforts to undermine or discredit the scientific consensus on global warming . |
97 | Anthony_Watts_(blogger) | according, again, to the official figures—during this past 10 years, if anything, mean global temperature, average world temperature, has slightly declined | Anthony Watts (blogger) Willard Anthony Watts ( born 1958 ) is an American blogger who runs Watts Up With That ? , a popular climate change denial blog that opposes the scientific consensus on climate change . A former television meteorologist and current radio meteorologist , he is also founder of the Surface Stations project , a volunteer initiative to document the condition of U.S. weather stations . The Heartland Institute helped fund some of Watts ' projects , including publishing a report on the Surface Stations project , and has invited him to be a paid speaker at the International Conference on Climate Change from 2008 to 2014 . |
2101 | Cloud | Clouds provide negative feedback | Cloud In meteorology , a cloud is an aerosol comprising a visible mass of minute liquid droplets , frozen crystals , or particles suspended in the atmosphere above the surface of a planetary body . The droplets and crystals may be made of water or various chemicals . On Earth , clouds are formed as a result of saturation of the air when it is cooled to its dew point , or when it gains sufficient moisture ( usually in the form of water vapor ) from an adjacent source to raise the dew point to the ambient temperature . They are seen in the Earth 's homosphere ( which includes the troposphere , stratosphere , and mesosphere ) . Nephology is the science of clouds which is undertaken in the cloud physics branch of meteorology . There are two systems of naming clouds in their respective layers of the atmosphere ; Latin in the troposphere and mostly alpha-numeric above the troposphere . Cloud types in the troposphere , the atmospheric layer closest to Earth 's surface , have Latin names due to the universal adaptation of Luke Howard 's nomenclature . Formally proposed in 1802 , it became the basis of a modern international system that classifies clouds into five physical forms and three altitude levels ( formerly known as étages ) . These physical types , in approximate ascending order of convective activity , include stratiform sheets , cirriform wisps and patches , stratocumuliform layers ( mainly structured as rolls , ripples , and patches ) , cumuliform heaps , and very large cumulonimbiform heaps that often show complex structure . The physical forms are cross-classified by the altitude levels to produce ten basic genus-types , most of which can be divided into species , and subdivided into varieties . Two cirriform clouds that form higher up in the stratosphere and mesosphere have common names for their main types , but are sub-classified alpha-numerically . They are relatively uncommon and are mostly seen in the polar regions of Earth . Clouds have been observed in the atmospheres of other planets and moons in the Solar System and beyond . However , due to their different temperature characteristics , they are often composed of other substances such as methane , ammonia , and sulfuric acid as well as water . Homospheric types determined by cross-classification of forms and levels . '' Homospheric types include the ten tropospheric genera and two additional major types above the troposphere . The cumulus genus includes three variants as defined by vertical size . |
197 | Earth | Plants need almost three times today's carbon dioxide content of the atmosphere to thrive. | 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 . |
2038 | El_Niño–Southern_Oscillation | Past Australian droughts occurred when global temperatures were lower than now and wetter years occurred when such temperatures were rising. | El Niño–Southern Oscillation El Niño -- Southern Oscillation ( ENSO ) is an irregularly periodical variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean , affecting much of the tropics and subtropics . The warming phase is known as El Niño and the cooling phase as La Niña . Southern Oscillation is the accompanying atmospheric component , coupled with the sea temperature change : El Niño is accompanied with high , and La Niña with low air surface pressure in the tropical western Pacific . The two periods last several months each ( typically occur every few years ) and their effects vary in intensity . The two phases relate to the Walker circulation , discovered by Gilbert Walker during the early twentieth century . The Walker circulation is caused by the pressure gradient force that results from a high pressure system over the eastern Pacific Ocean , and a low pressure system over Indonesia . When the Walker circulation weakens or reverses , an El Niño results , causing the ocean surface to be warmer than average , as upwelling of cold water occurs less or not at all . An especially strong Walker circulation causes a La Niña , resulting in cooler ocean temperatures due to increased upwelling . Mechanisms that cause the oscillation remain under study . The extremes of this climate pattern 's oscillations cause extreme weather ( such as floods and droughts ) in many regions of the world . Developing countries dependent upon agriculture and fishing , particularly those bordering the Pacific Ocean , are the most affected . |
812 | Puerto_Rico | The human contribution can be up to 30 percent or so of the total rainfall coming out of the storm | Puerto Rico Puerto Rico ( Spanish for `` Rich Port '' ) , officially the Commonwealth of Puerto Rico ( Estado Libre Asociado de Puerto Rico , `` Free Associated State of Puerto Rico '' ) and briefly called Porto Rico , is an unincorporated territory of the United States located in the northeast Caribbean Sea . It is an archipelago that includes the main island of Puerto Rico and a number of smaller ones such as Mona , Culebra , and Vieques . The capital and most populous city is San Juan . Its official languages are Spanish and English , though Spanish predominates . The island 's population is approximately 3.4 million . Puerto Rico 's rich history , tropical climate , diverse natural scenery , traditional cuisine , and attractive tax incentives make it a popular destination for travelers from around the world . Originally populated by the indigenous Taíno people , the island was claimed in 1493 by Christopher Columbus for the Crown of Castile , and it later endured invasion attempts from the French , Dutch , and British . Four centuries of Spanish colonial government transformed the island 's ethnic , cultural and physical landscapes primarily with waves of African slaves , and Canarian , and Andalusian settlers . In the Spanish imperial imagination , Puerto Rico played a secondary , but strategic role when compared to wealthier colonies like Peru and Mexico . Such a distant administrative control continued right up until the end of the 19th century helping to produce a distinctive creole Hispanic culture and language that combined elements from the Natives , Africans , and Iberian people . In 1898 , following the Spanish -- American War , the United States appropriated Puerto Rico together with most former Spanish colonies under the terms of the Treaty of Paris . Puerto Ricans are considered natural-born citizens of the United States . However , Puerto Rico does not have a vote in the United States Congress , which governs the territory with full jurisdiction under the Puerto Rico Federal Relations Act of 1950 . As a U.S. territory , American citizens residing on the island are disenfranchised at the national level and may not vote for president and vice president of the United States . However , Congress approved a local constitution , allowing U.S. citizens on the territory to elect a governor . A 2012 referendum showed a majority ( 54 % of those who voted ) disagreed with `` the present form of territorial status '' , with full statehood as the preferred option among those who voted for a change of status , although a significant number of people did not answer the second question from the referendum . A fifth referendum will be held in June 2017 , and `` Statehood '' and `` Independence/Free Association '' were initially the only available options . However , at the recommendation of the Department of Justice , a `` current territorial status '' option will be added . In early 2017 , the Puerto Rican government-debt crisis posed serious problems for the government . The outstanding bond debt had climbed to $ 70 billion at a time with 12.4 % unemployment . The debt had been increasing during a decade long recession . This was the second major financial crisis to affect the island after the Great Depression when the U.S. government , in 1935 , provided relief efforts through the Puerto Rico Reconstruction Administration . On May 3 , 2017 , Puerto Rico 's financial oversight board in the U.S. District Court in Puerto Rico filed the debt restructuring petition which was made under Title III of PROMESA . |
2012 | Carbon_Pollution_Reduction_Scheme | U.S. Sen. Ron Johnson "led the fight to let polluters release unlimited amounts of carbon pollution and took nearly $225,000 from polluters." | Carbon Pollution Reduction Scheme The Carbon Pollution Reduction Scheme ( or CPRS ) was a cap-and-trade emissions trading scheme for anthropogenic greenhouse gases proposed by the Rudd government , as part of its climate change policy , which had been due to commence in Australia in 2010 . It marked a major change in the energy policy of Australia . The policy began to be formulated in April 2007 , when the federal Labor Party was in Opposition and the six Labor-controlled states commissioned an independent review on energy policy , the Garnaut Climate Change Review , which published a number of reports . After Labor won the 2007 federal election and formed government , it published a Green Paper on climate change for discussion and comment . The Federal Treasury then modelled some of the financial and economic impacts of the proposed CPRS scheme . The Rudd government published a final White Paper on 15 December 2008 , and announced that legislation was intended to take effect in July 2010 ; but the legislation for the CPRS ( aka ETS ) failed to gain the numbers in the Senate and was twice rejected creating a double dissolution election trigger . A bitter political debate within the Coalition Opposition saw Opposition leader Malcolm Turnbull lose the leadership to the anti-CPRS Tony Abbott . The Rudd government did not call an election and in April 2010 , Rudd deferred plans for the CPRS . After the 2010 federal election , the Gillard Government was able to get the Carbon Pricing Mechanism ( CPM ) passed into law as part of the Clean Energy Futures Package ( CEF ) in 2011 , and became effective on 1 July 2012 . However , after the 2013 federal election there was a change in government , and the Abbott Government repealed the CEF package on 17 July 2014 . Due to the great deal of policy uncertainty surrounding the scheme , organizations in Australia responded in a rather informal and tepid manner and largely withheld from making any large-scale investments in emissions reductions technology during the scheme 's operation . |
2004 | Al_Gore | They (Clinton and Obama) have never to my knowledge been involved in legislation nor hearings nor engagement on this issue (climate change). | Al Gore Albert Arnold Gore Jr. ( born March 31 , 1948 ) is an American politician and environmentalist who served as the 45th Vice President of the United States from 1993 to 2001 under President Bill Clinton . He was Clinton 's running mate in their successful campaign in 1992 , and was re-elected in 1996 . At the end of Clinton 's second term , Gore was picked as the Democratic nominee for the 2000 presidential election . After leaving office , Gore remained prominent as an author and environmental activist , whose work in climate change activism earned him ( jointly with the IPCC ) the Nobel Peace Prize in 2007 . Gore was an elected official for 24 years . He was a Congressman from Tennessee ( 1977 -- 85 ) and from 1985 to 1993 served as one of the state 's Senators . He served as Vice President during the Clinton administration from 1993 to 2001 . In the 2000 presidential election , in what was one of the closest presidential races in history , Gore won the popular vote but lost in the Electoral College to Republican George W. Bush . A controversial election dispute over a vote recount in Florida was settled by the U.S. Supreme Court , which ruled 5 -- 4 in favor of Bush . Gore is the founder and current chair of the Alliance for Climate Protection , the co-founder and chair of Generation Investment Management and the now-defunct Current TV network , a member of the Board of Directors of Apple Inc. , and a senior adviser to Google . Gore is also a partner in the venture capital firm Kleiner Perkins Caufield & Byers , heading its climate change solutions group . He has served as a visiting professor at Middle Tennessee State University , Columbia University Graduate School of Journalism , Fisk University , and the University of California , Los Angeles . He served on the Board of Directors of World Resources Institute . Gore has received a number of awards including the Nobel Peace Prize ( joint award with the Intergovernmental Panel on Climate Change , 2007 ) , a Grammy Award for Best Spoken Word Album ( 2009 ) for his book An Inconvenient Truth , a Primetime Emmy Award for Current TV ( 2007 ) , and a Webby Award ( 2005 ) . Gore was also the subject of the Academy Award-winning ( 2007 ) documentary An Inconvenient Truth in 2006 . In 2007 , he was named a runner-up for Time 2007 Person of the Year . |
2574 | Coral | On a world scale coral reefs are in decline. | Coral Corals are marine invertebrates in the class Anthozoa of phylum Cnidaria . They typically live in compact colonies of many identical individual polyps . The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton . A coral `` group '' is a colony of myriad genetically identical polyps . Each polyp is a sac-like animal typically only a few millimeters in diameter and a few centimeters in length . A set of tentacles surround a central mouth opening . An exoskeleton is excreted near the base . Over many generations , the colony thus creates a large skeleton that is characteristic of the species . Individual heads grow by asexual reproduction of polyps . Corals also breed sexually by spawning : polyps of the same species release gametes simultaneously over a period of one to several nights around a full moon . Although some corals can catch small fish and plankton using stinging cells on their tentacles , most corals obtain the majority of their energy and nutrients from photosynthetic unicellular dinoflagellates in the genus Symbiodinium that live within their tissues . These are commonly known as zooxanthellae and the corals that contain them are zooxanthellate corals . Such corals require sunlight and grow in clear , shallow water , typically at depths shallower than 60 m. Corals are major contributors to the physical structure of the coral reefs that develop in tropical and subtropical waters , such as the enormous Great Barrier Reef off the coast of Queensland , Australia . Other corals do not rely on zooxanthellae and can live in much deeper water , with the cold-water genus Lophelia surviving as deep as 3000 m . Some have been found on the Darwin Mounds , north-west of Cape Wrath , Scotland . Corals have also been found as far north as off the coast of Washington State and the Aleutian Islands . |
1516 | U.S._state_and_territory_temperature_extremes | the U.S. is shattering high temperature records far more frequently than it is shattering low temperature records. | U.S. state and territory temperature extremes The following table lists the highest and lowest temperatures recorded in the 50 U.S. states, the District of Columbia, and the 5 inhabited U.S. territories during the past two centuries, in both Fahrenheit and Celsius. If two dates have the same temperature record (e.g. record low of 40°F in 1911 in Aibonito and 1966 in San Sebastian in Puerto Rico), only the most recent date is shown. |
556 | Montclair,_New_Jersey | The April low temperatures here are now about 6 degrees Fahrenheit warmer than they used to be. | Montclair, New Jersey Montclair ( -LSB- mɒntˈklɛər -RSB- or -LSB- mɒŋˈklɛər -RSB- ) is a township in Essex County , New Jersey , United States . As of the 2010 United States Census , the township 's population was 37,669 , reflecting a decline of 1,308 ( -3.4 % ) from the 38,977 counted in the 2000 Census , which had in turn increased by 1,248 ( +3.3 % ) from the 37,729 counted in the 1990 Census . , it was the 60th-most-populous municipality in New Jersey . Montclair was first formed as a township on April 15 , 1868 , from portions of Bloomfield Township , so that a second railroad could be built to Montclair . After a referendum held on February 21 , 1894 , Montclair was reincorporated as a town , effective February 24 , 1894 . It derives its name from the French mont clair , meaning `` clear mountain '' or `` bright mountain . '' In 1980 , after multiple protests filed by Montclair officials regarding the inequities built into the federal revenue sharing system , Montclair passed a referendum changing its name to the `` Township of Montclair , '' becoming the third of more than a dozen Essex County municipalities to reclassify themselves as townships to take advantage of federal revenue sharing policies that allocated townships a greater share of government aid to municipalities on a per capita basis . |
1673 | Greenhouse_gas | When CO2 was higher in the past, the sun was cooler. | 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 . |
549 | Cloud | The extent of climate change's influence on the jet stream is an intense subject of research. | Cloud In meteorology , a cloud is an aerosol comprising a visible mass of minute liquid droplets , frozen crystals , or particles suspended in the atmosphere above the surface of a planetary body . The droplets and crystals may be made of water or various chemicals . On Earth , clouds are formed as a result of saturation of the air when it is cooled to its dew point , or when it gains sufficient moisture ( usually in the form of water vapor ) from an adjacent source to raise the dew point to the ambient temperature . They are seen in the Earth 's homosphere ( which includes the troposphere , stratosphere , and mesosphere ) . Nephology is the science of clouds which is undertaken in the cloud physics branch of meteorology . There are two systems of naming clouds in their respective layers of the atmosphere ; Latin in the troposphere and mostly alpha-numeric above the troposphere . Cloud types in the troposphere , the atmospheric layer closest to Earth 's surface , have Latin names due to the universal adaptation of Luke Howard 's nomenclature . Formally proposed in 1802 , it became the basis of a modern international system that classifies clouds into five physical forms and three altitude levels ( formerly known as étages ) . These physical types , in approximate ascending order of convective activity , include stratiform sheets , cirriform wisps and patches , stratocumuliform layers ( mainly structured as rolls , ripples , and patches ) , cumuliform heaps , and very large cumulonimbiform heaps that often show complex structure . The physical forms are cross-classified by the altitude levels to produce ten basic genus-types , most of which can be divided into species , and subdivided into varieties . Two cirriform clouds that form higher up in the stratosphere and mesosphere have common names for their main types , but are sub-classified alpha-numerically . They are relatively uncommon and are mostly seen in the polar regions of Earth . Clouds have been observed in the atmospheres of other planets and moons in the Solar System and beyond . However , due to their different temperature characteristics , they are often composed of other substances such as methane , ammonia , and sulfuric acid as well as water . Homospheric types determined by cross-classification of forms and levels . '' Homospheric types include the ten tropospheric genera and two additional major types above the troposphere . The cumulus genus includes three variants as defined by vertical size . |
1619 | West_Side_Highway | Hansen predicted in 1988 the West Side Highway would be underwater in 20 years. | West Side Highway The West Side Highway ( officially the Joe DiMaggio Highway ) is a mostly surface section of New York State Route 9A ( NY 9A ) that runs from West 72nd Street along the Hudson River to the southern tip of Manhattan in New York City . It replaced the West Side Elevated Highway , built between 1929 and 1951 , which was shut down in 1973 due to neglect and lack of maintenance , and was dismantled by 1989 . The term `` West Side Highway '' is often mistakenly used , particularly by the news media traffic reporters , to include the roadway north of 72nd Street which is properly known as the Henry Hudson Parkway . The current highway was complete by 2001 , but required some reconstruction due to damage sustained in the 9/11 attacks . It uses the surface streets that existed before the elevated highway was built : West Street , Eleventh Avenue and Twelfth Avenue . A short section of 12th Avenue still runs between 125th and 138th Streets , under the Riverside Drive Viaduct . Eleventh Avenue is a separate street north of 22nd Street . The portion between West 42nd Street and Canal Street is part of the Lincoln Highway . |
905 | Global_warming | "Some experts, such as UN climate scientist Dr. Indur Goklany, have defended rising CO2 levels as a good thing for humanity. | 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 . |
1077 | Global_warming_in_Antarctica | Antarctic ice fluctuates wildly year to year, and the link to man-made global warming there is not clear, NASA ice expert Walt Meier said. | Global warming in Antarctica The effects of global warming in Antarctica may include rising temperatures and increasing snow melt . |
1626 | Attribution_of_recent_climate_change | Climate reacts to whatever forces it to change at the time; humans are now the dominant forcing. | Attribution of recent climate change Attribution of recent climate change is the effort to scientifically ascertain mechanisms responsible for recent climate changes on Earth , commonly known as ` global warming ' . The effort has focused on changes observed during the period of instrumental temperature record , when records are most reliable ; particularly in the last 50 years , when human activity has grown fastest and observations of the troposphere have become available . The dominant mechanisms are anthropogenic , i.e. , the result of human activity . They are : increasing atmospheric concentrations of greenhouse gases global changes to land surface , such as deforestation increasing atmospheric concentrations of aerosols . There are also natural mechanisms for variation including climate oscillations , changes in solar activity , and volcanic activity . According to the Intergovernmental Panel on Climate Change ( IPCC ) , it is `` extremely likely '' that human influence was the dominant cause of global warming between 1951 and 2010 . The IPCC defines `` extremely likely '' as indicating a probability of 95 to 100 % , based on an expert assessment of all the available evidence . Multiple lines of evidence support attribution of recent climate change to human activities : A basic physical understanding of the climate system : greenhouse gas concentrations have increased and their warming properties are well-established . Historical estimates of past climate changes suggest that the recent changes in global surface temperature are unusual . Computer-based climate models are unable to replicate the observed warming unless human greenhouse gas emissions are included . Natural forces alone ( such as solar and volcanic activity ) can not explain the observed warming . The IPCC 's attribution of recent global warming to human activities is a view shared by the scientific community , and is also supported by 196 other scientific organizations worldwide ( see also : scientific opinion on climate change ) . |
1719 | Air_pollution | When you account for all of the costs associated with burning coal and other fossil fuels, like air pollution and health effects, in reality they are significantly more expensive than most renewable energy sources. | Air pollution Air pollution occurs when harmful substances including particulates and biological molecules are introduced into Earth 's atmosphere . It may cause diseases , allergies or death in humans ; it may also cause harm to other living organisms such as animals and food crops , and may damage the natural or built environment . Human activity and natural processes can both generate air pollution . Indoor air pollution and poor urban air quality are listed as two of the world 's worst toxic pollution problems in the 2008 Blacksmith Institute World 's Worst Polluted Places report . According to the 2014 WHO report , air pollution in 2012 caused the deaths of around 7 million people worldwide , an estimate roughly matched by the International Energy Agency . |
1868 | Presidency_of_Donald_Trump | Currently, Florida is one of only five states in the nation that prohibit citizens from buying electricity from companies that will put solar panels on your home or business. | Presidency of Donald Trump The presidency of Donald Trump began at noon EST on January 20 , 2017 , the day that Donald Trump was inaugurated as the 45th President of the United States , succeeding Barack Obama . Trump , a Republican , was a businessman from New York City at the time of his victory in the 2016 presidential election over Democrat Hillary Clinton . His running mate , former Governor Mike Pence of Indiana , took office as the 48th Vice President of the United States on the same day . Trump 's term in office is set to end on January 20 , 2021 , though he is eligible for election to a second term and has declared his intention to run . During his first few months in office , , Trump has issued 36 executive orders and 25 presidential memoranda . The executive orders 13769 and 13780 dealing with denying admission to the US of people from several foreign countries have been blocked by federal courts . Trump 's nominee to the Supreme Court , Neil Gorsuch , was confirmed by the United States Senate on April 7 , 2017 . |
2557 | Climate_change_(general_concept) | Poorly understood aspects of climate change do not change the fact that a great deal of climate science is well understood. | Climate change (general concept) Climate variability includes all the variations in the climate that last longer than individual weather events, whereas the term climate change only refers to those variations that persist for a longer period of time, typically decades or more. In the time since the industrial revolution the climate has increasingly been affected by human activities that are causing global warming and climate change.The climate system receives nearly all of its energy from the sun. The climate system also radiates energy to outer space. The balance of incoming and outgoing energy, and the passage of the energy through the climate system, determines Earth\'s energy budget. When the incoming energy is greater than the outgoing energy, earth\'s energy budget is positive and the climate system is warming. If more energy goes out, the energy budget is negative and earth experiences cooling.\nThe energy moving through Earth\'s climate system finds expression in weather, varying on geographic scales and time. Long-term averages and variability of weather in a region constitute the region\'s climate. Such changes can be the result of "internal variability", when natural processes inherent to the various parts of the climate system alter the distribution of energy. Examples include variability in ocean basins such as the Pacific decadal oscillation and Atlantic multidecadal oscillation. Climate variability can also result from external forcing, when events outside of the climate system\'s components nonetheless produce changes within the system. Examples include changes in solar output and volcanism.\nClimate variability has consequences for sea level changes, plant life, and mass extinctions; it also affects human societies. |
2092 | Polar_bear | Polar bear numbers are increasing | Polar bear The polar bear ( ursus #Latin maritimus #Latin ) is a carnivorous bear whose native range lies largely within the Arctic Circle , encompassing the Arctic Ocean , its surrounding seas and surrounding land masses . It is a large bear , approximately the same size as the omnivorous Kodiak bear ( Ursus arctos middendorffi ) . A boar ( adult male ) weighs around 350 -- , while a sow ( adult female ) is about half that size . Although it is the sister species of the brown bear , it has evolved to occupy a narrower ecological niche , with many body characteristics adapted for cold temperatures , for moving across snow , ice and open water , and for hunting seals , which make up most of its diet . Although most polar bears are born on land , they spend most of their time on the sea ice . Their scientific name means `` maritime bear '' and derives from this fact . Polar bears hunt their preferred food of seals from the edge of sea ice , often living off fat reserves when no sea ice is present . Because of their dependence on the sea ice , polar bears are classified as marine mammals ; an alternative basis for classification as marine mammals is that they depend on the ocean as their main food source . Because of expected habitat loss caused by climate change , the polar bear is classified as a vulnerable species , and at least three of the nineteen polar bear subpopulations are currently in decline . For decades , large-scale hunting raised international concern for the future of the species , but populations rebounded after controls and quotas began to take effect . For thousands of years , the polar bear has been a key figure in the material , spiritual , and cultural life of circumpolar peoples , and polar bears remain important in their cultures . |
914 | Energy_policy_of_the_United_States | The Clean Power Plan, a major component of fulfilling the agreement, would spike energy costs for working and middle-class Texans by 16% by 2030, according to the Economic Reliability Council of Texas | Energy policy of the United States The energy policy of the United States is determined by federal , state , and local entities in the United States , which address issues of energy production , distribution , and consumption , such as building codes and gas mileage standards . Energy policy may include legislation , international treaties , subsidies and incentives to investment , guidelines for energy conservation , taxation and other public policy techniques . Several mandates have been proposed over the years , such as gasoline will never exceed $ 1.00 / gallon ( Nixon ) , and the United States will never again import as much oil as it did in 1977 ( Carter ) , but no comprehensive long-term energy policy has been proposed , although there has been concern over this failure . Three Energy Policy Acts have been passed , in 1992 , 2005 , and 2007 , which include many provisions for conservation , such as the Energy Star program , and energy development , with grants and tax incentives for both renewable energy and non-renewable energy . There is also criticism that federal energy policies since the 1973 oil crisis have been dominated by crisis-mentality thinking , promoting expensive quick fixes and single-shot solutions that ignore market and technology realities . Instead of providing stable rules that support basic research while leaving plenty of scope for American entrepreneurship and innovation , congresses and presidents have repeatedly backed policies which promise solutions that are politically expedient , but whose prospects are doubtful , without adequate consideration of the dollar costs , environmental costs , or national security costs of their actions . State-specific energy-efficiency incentive programs also play a significant role in the overall energy policy of the United States . The United States refused to endorse the Kyoto Protocol , preferring to let the market drive CO2 reductions to mitigate global warming , which will require CO2 emission taxation . The administration of Barack Obama has proposed an aggressive energy policy reform , including the need for a reduction of CO2 emissions , with a cap and trade program , which could help encourage more clean renewable , sustainable energy development . Thanks to new technologies such as fracking , the United States has in 2014 resumed its former role as the top oil producer in the world . |
1369 | El_Niño | "With a record El Niño, we should have experienced record high temperatures. | 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 '' . |
1434 | Mangrove | Just 0.7% of the world's forests are coastal mangroves, yet they store up to 10 times as much carbon per hectare as tropical forests. | Mangrove A mangrove is a shrub or small tree that grows in coastal saline or brackish water . The term is also used for tropical coastal vegetation consisting of such species . Mangroves occur worldwide in the tropics and subtropics , mainly between latitudes ° N and ° S.The total mangrove forest area of the world in 2000 was 137,800 km2 , spanning 118 countries and territories . Mangroves are salt tolerant trees , also called halophytes , and are adapted to life in harsh coastal conditions . They contain a complex salt filtration system and complex root system to cope with salt water immersion and wave action . They are adapted to the low oxygen ( anoxic ) conditions of waterlogged mud . The word is used in at least three senses : ( 1 ) most broadly to refer to the habitat and entire plant assemblage or mangal , for which the terms mangrove forest biome , and mangrove swamp are also used , ( 2 ) to refer to all trees and large shrubs in the mangrove swamp , and ( 3 ) narrowly to refer to the mangrove family of plants , the Rhizophoraceae , or even more specifically just to mangrove trees of the genus Rhizophora . The mangrove biome , or mangal , is a distinct saline woodland or shrubland habitat characterized by depositional coastal environments , where fine sediments ( often with high organic content ) collect in areas protected from high-energy wave action . The saline conditions tolerated by various mangrove species range from brackish water , through pure seawater ( 3 to 4 % ) , to water concentrated by evaporation to over twice the salinity of ocean seawater ( up to 9 % ) . |
311 | Climate_of_Argentina | there has been no systematic increase in the frequency of extreme weather events, | Climate of Argentina The climate of Argentina is a complex subject : the vast size of the country and considerable variation in altitude make for a wide range of climate types . Argentina has four seasons : winter ( June -- August ) , spring ( September -- November ) , summer ( December -- February ) and autumn ( March -- May ) , all featuring different weather conditions . Summers are the warmest and wettest season in most of the country except in most of Patagonia where it is the driest season . Winters are normally mild in the north , cool in the center and cold in the southern parts with the latter experiencing frequent frost and snow . Because southern parts of the country are moderated by the surrounding oceans , the cold is less intense and prolonged than areas at comparable latitudes in the northern hemisphere . Spring and autumn are transition seasons that generally feature mild weather . Many regions have different , often contrasting , microclimates . In general , northern parts of the country are characterized by hot , humid , rainy summers and mild winters with periodic droughts . Mesopotamia , in the northeast is characterized by high temperatures and abundant precipitation throughout the year with droughts being uncommon . West of this lies the Chaco region , which is the warmest region in Argentina . Precipitation in the Chaco region decreases westwards , resulting in the vegetation changing from forests in the east to shrubs in the west . Northwest Argentina is predominantly dry and hot although the rugged topography makes it climatically diverse , ranging from the cold , dry Puna to thick jungles . The center of the country , which includes the Pampas to the east and the drier Cuyo region to the west has hot summers with occasional tornadoes and thunderstorms , and cool , dry winters . Patagonia , in the southern parts of the country has a dry climate with warm summers and cold winters characterized by strong winds throughout the year and one of the strongest precipitation gradients in the world . High elevations at all latitudes experience cooler conditions , and the mountainous zones can see heavy snowfall . The geographic and geomorphic characteristics of Argentina tend to create extreme weather conditions , often leading to natural disasters that negatively impact the country both economically and socially . The Pampas , where many of the large cities are located , has a flat topography and poor water drainage , making it vulnerable to flooding . Severe storms can lead to tornados , damaging hail , storm surges , and high winds , causing extensive damage to houses and infrastructure , displacing thousands of people and causing significant loss of life . Extreme temperature events such as heat waves and cold waves impact rural and urban areas by negatively impacting agriculture , one of the main economic activities of the country , and by increasing energy demand , which can lead to energy shortages . Argentina is vulnerable and will likely be significantly impacted by climate change . Temperatures have increased in the last century while the observed changes in precipitation are variable , with some areas receiving more and other areas less . These changes have impacted river flow , increased the frequency of extreme weather events , and led to the retreat of glaciers . Based on the projections for both precipitation and temperatures , these climatic events are likely to increase in severity and create new problems associated with climate change in the country . |
1773 | Sea_level_rise | The global trend is calculated from hundreds of CO2 measuring stations and confirmed by satellites. | 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 . |
2754 | Ronald_Reagan | "There are many urgent priorities that need the attention of Congress, and it is not for me as an invited guest in your country to say what they are. | Ronald Reagan Ronald Wilson Reagan ( -LSB- ˈrɒnəld_ˈwɪlsən_ˈreɪɡən -RSB- ) ( February 6 , 1911 -- June 5 , 2004 ) was an American politician and actor who served as the 40th President of the United States from 1981 to 1989 . Before his presidency , he was the 33rd Governor of California , from 1967 to 1975 , after a career as a Hollywood actor and union leader . Raised in a poor family in small towns of northern Illinois , Reagan graduated from Eureka College in 1932 and worked as a sports announcer on several regional radio stations . After moving to Hollywood in 1937 , he became an actor and starred in a few major productions . Reagan was twice elected President of the Screen Actors Guild , the labor union for actors , where he worked to root out Communist influence . In the 1950s , he moved into television and was a motivational speaker at General Electric factories . Having been a lifelong Democrat , his views changed . He became a conservative and in 1962 switched to the Republican Party . In 1964 , Reagan 's speech , `` A Time for Choosing '' , in support of Barry Goldwater 's foundering presidential campaign , earned him national attention as a new conservative spokesman . Building a network of supporters , he was elected Governor of California in 1966 . As governor , Reagan raised taxes , turned a state budget deficit to a surplus , challenged the protesters at the University of California , ordered National Guard troops in during a period of protest movements in 1969 , and was re-elected in 1970 . He twice ran unsuccessfully for the Republican nomination for the U.S. presidency in 1968 and 1976 ; four years later , he easily won the nomination outright , becoming the oldest elected U.S. president up to that time , defeating incumbent Jimmy Carter in 1980 . Entering the presidency in 1981 , Reagan implemented sweeping new political and economic initiatives . His supply-side economic policies , dubbed `` Reaganomics '' , advocated tax rate reduction to spur economic growth , control of the money supply to curb inflation , economic deregulation , and reduction in government spending . In his first term he survived an assassination attempt , spurred the War on Drugs , and fought public sector labor . Over his two terms , the economy saw a reduction of inflation from 12.5 % to 4.4 % , and an average annual growth of real GDP of 3.4 ; while Reagan did enact cuts in domestic discretionary spending , tax cuts and increased military spending contributed to increased federal outlays overall , even after adjustment for inflation . During his re-election bid , Reagan campaigned on the notion that it was `` Morning in America '' , winning a landslide in 1984 with the largest electoral college victory in American history . Foreign affairs dominated his second term , including ending of the Cold War , the bombing of Libya , and the Iran -- Contra affair . Publicly describing the Soviet Union as an `` evil empire '' , and during his famous speech at the Brandenburg Gate , President Reagan challenged Soviet General Secretary Mikhail Gorbachev to `` tear down this wall ! '' . He transitioned Cold War policy from détente to rollback , by escalating an arms race with the USSR while engaging in talks with Gorbachev , which culminated in the INF Treaty , shrinking both countries ' nuclear arsenals . Reagan 's presidency came during the decline of the Soviet Union and just ten months after the end of his term , the Berlin Wall fell , and on December 26 , 1991 , nearly three years after he left office , the Soviet Union collapsed . Leaving office in 1989 , Reagan held an approval rating of sixty-eight percent , matching those of Franklin D. Roosevelt , and later Bill Clinton , as the highest ratings for departing presidents in the modern era . He was the first president since Dwight D. Eisenhower to serve two full terms , after a succession of five prior presidents failed to do so . While having planned an active post-presidency , in 1994 Reagan disclosed his diagnosis with Alzheimer 's disease earlier that year , appearing publicly for the last time at the funeral of Richard Nixon ; he died ten years later in 2004 at the age of 93 ; Reagan had the second-longest life out of all the presidents ; the current longest lifespan of a president is held by Gerald Ford , who died two years after Reagan . An icon among Republicans , he is viewed favorably in historian rankings of U.S. presidents , and his tenure constituted a realignment toward conservative policies in the U.S. |
1010 | Arctic | "'The Arctic may be remote, but changes that occur there directly affect us. | Arctic The Arctic ( -LSB- ˈɑrktɪk -RSB- or -LSB- ˈɑrtɪk -RSB- ) is a polar region located at the northernmost part of Earth . The Arctic consists of the Arctic Ocean , adjacent seas , and parts of Alaska ( United States ) , Canada , Finland , Greenland ( Denmark ) , Iceland , Norway , Russia and Sweden . Land within the Arctic region has seasonally varying snow and ice cover , with predominantly treeless permafrost-containing tundra . Arctic seas contain seasonal sea ice in many places . The Arctic region is a unique area among Earth 's ecosystems . For example , the cultures in the region and the Arctic indigenous peoples have adapted to its cold and extreme conditions . In recent years , Arctic sea ice decline has been caused by global warming . Life in the Arctic includes organisms living in the ice , zooplankton and phytoplankton , fish and marine mammals , birds , land animals , plants and human societies . Arctic land is bordered by the subarctic . |
2147 | Creep_(deformation) | An exponential increase in CO2 will result in a linear increase in temperature | Creep (deformation) In materials science , creep ( sometimes called cold flow ) is the tendency of a solid material to move slowly or deform permanently under the influence of mechanical stresses . It can occur as a result of long-term exposure to high levels of stress that are still below the yield strength of the material . Creep is more severe in materials that are subjected to heat for long periods , and generally increases as they near their melting point . The rate of deformation is a function of the material properties , exposure time , exposure temperature and the applied structural load . Depending on the magnitude of the applied stress and its duration , the deformation may become so large that a component can no longer perform its function -- for example creep of a turbine blade will cause the blade to contact the casing , resulting in the failure of the blade . Creep is usually of concern to engineers and metallurgists when evaluating components that operate under high stresses or high temperatures . Creep is a deformation mechanism that may or may not constitute a failure mode . For example , moderate creep in concrete is sometimes welcomed because it relieves tensile stresses that might otherwise lead to cracking . Unlike brittle fracture , creep deformation does not occur suddenly upon the application of stress . Instead , strain accumulates as a result of long-term stress . Therefore , creep is a `` time-dependent '' deformation . |
1155 | Climate_change_in_the_United_States | But observations, such as those on our CO2 Coalition website, show that increased CO2 levels over the next century will cause modest and beneficial warming—perhaps as much as one degree Celsius (1.8 degrees Fahrenheit) | 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. |
2867 | Creation–evolution_controversy | Skeptics who oppose scientific findings that threaten their world view are far closer to Galileo's belief-based critics in the Catholic Church. | Creation–evolution controversy The creation -- evolution controversy ( also termed the creation vs. evolution debate or the origins debate ) involves an ongoing , recurring cultural , political , and theological dispute about the origins of the Earth , of humanity , and of other life . Within the Christian world creationism was once widely believed to be true , but since the mid-19th century evolution by natural selection has been established as an empirical scientific fact . Efforts to sustain the traditional view are widely regarded in the scientific community as pseudoscience . While the controversy has a long history , today it has retreated to be mainly over what constitutes good science education , with the politics of creationism primarily focusing on the teaching of creation and evolution in public education . Among majority-Christian countries , the debate is most prominent in the United States , and to a lesser extent in Europe and elsewhere , and is often portrayed as part of a culture war . Parallel controversies also exist in some other religious communities , such as the more fundamentalist branches of Judaism and Islam . Christian fundamentalists dispute the evidence of common descent of humans and other animals as demonstrated in modern paleontology , genetics , histology and cladistics and those other sub-disciplines which are based upon the conclusions of modern evolutionary biology , geology , cosmology , and other related fields . They argue for the Abrahamic accounts of creation , framing them as reputable science ( `` creation science '' ) . The Catholic Church now recognizes the existence of evolution ( see Catholic Church and evolution ) . Pope Francis has stated : `` God is not a divine being or a magician , but the Creator who brought everything to life ... Evolution in nature is not inconsistent with the notion of creation , because evolution requires the creation of beings that evolve . '' The rules of genetic evolutionary inheritance were first discovered by a Catholic priest , the Augustinian monk Gregor Mendel , who is known today as the founder of modern genetics . According to a 2014 Gallup survey , `` More than four in 10 Americans continue to believe that God created humans in their present form 10,000 years ago , a view that has changed little over the past three decades . Half of Americans believe humans evolved , with the majority of these saying God guided the evolutionary process . However , the percentage who say God was not involved is rising . '' The debate is sometimes portrayed as being between science and religion , and the United States National Academy of Sciences states : |
409 | Greenhouse_gas | as time progresses and fossil fuel emissions increase, the number of record highs should increase and record lows should decrease. | 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 . |
1251 | Clathrate_gun_hypothesis | "Underneath the permafrost there are sediments full of methane hydrates. | Clathrate gun hypothesis The clathrate gun hypothesis is the popular name given to the hypothesis that increases in sea temperatures ( and/or drops in sea levels ) can trigger the sudden release of methane from methane clathrate compounds buried in seabeds and that are contained within seabed permafrost which , because methane itself is a powerful greenhouse gas , leads to further temperature rise and further methane clathrate destabilization -- in effect initiating a runaway process as irreversible , once started , as the firing of a gun . In its original form , the hypothesis proposed that the `` clathrate gun '' could cause abrupt runaway warming on a timescale less than a human lifetime . It was thought to be responsible for warming events in and at the end of the last glacial maximum , however this is now thought to be unlikely . However , there is stronger evidence that runaway methane clathrate breakdown may have caused drastic alteration of the ocean environment ( such as ocean acidification and ocean stratification ) and of the atmosphere of earth on a number of occasions in the past , over timescales of tens of thousands of years . These events include the Paleocene -- Eocene Thermal Maximum 56 million years ago , and most notably the Permian -- Triassic extinction event , when up to 96 % of all marine species became extinct , 252 million years ago . |
2212 | General_circulation_model | While there are uncertainties with climate models, they successfully reproduce the past and have made predictions that have been subsequently confirmed by observations. | General circulation model A general circulation model ( GCM ) is a type of climate model . It employs a mathematical model of the general circulation of a planetary atmosphere or ocean . It uses the Navier -- Stokes equations on a rotating sphere with thermodynamic terms for various energy sources ( radiation , latent heat ) . These equations are the basis for computer programs used to simulate the Earth 's atmosphere or oceans . Atmospheric and oceanic GCMs ( AGCM and OGCM ) are key components along with sea ice and land-surface components . GCMs and global climate models are used for weather forecasting , understanding the climate and forecasting climate change . Versions designed for decade to century time scale climate applications were originally created by Syukuro Manabe and Kirk Bryan at the Geophysical Fluid Dynamics Laboratory in Princeton , New Jersey . These models are based on the integration of a variety of fluid dynamical , chemical and sometimes biological equations . |
197 | Deforestation | Plants need almost three times today's carbon dioxide content of the atmosphere to thrive. | Deforestation Deforestation , clearance or clearing is the removal of a forest or stand of trees where the land is thereafter converted to a non-forest use . Examples of deforestation include conversion of forestland to farms , ranches , or urban use . The most concentrated deforestation occurs in tropical rainforests . About 30 % of Earth 's land surface is covered by forests . Deforestation occurs for multiple reasons : trees are cut down to be used for building or sold as fuel , ( sometimes in the form of charcoal or timber ) , while cleared land is used as pasture for livestock and plantation . The removal of trees without sufficient reforestation has resulted in damage to habitat , biodiversity loss and aridity . It has adverse impacts on biosequestration of atmospheric carbon dioxide . Deforestation has also been used in war to deprive the enemy of vital resources and cover for its forces . Modern examples of this were the use of Agent Orange by the British military in Malaya during the Malayan Emergency and the United States military in Vietnam during the Vietnam War . As of 2005 , net deforestation rates have ceased to increase in countries with a per capita GDP of at least US$ 4,600 . Deforested regions typically incur significant adverse soil erosion and frequently degrade into wasteland . Disregard of ascribed value , lax forest management and deficient environmental laws are some of the factors that allow deforestation to occur on a large scale . In many countries , deforestation , both naturally occurring and human-induced , is an ongoing issue . Deforestation causes extinction , changes to climatic conditions , desertification , and displacement of populations as observed by current conditions and in the past through the fossil record . More than half of all plant and land animal species in the world live in tropical forests . Between 2000 and 2012 , 2.3 e6sqkm of forests around the world were cut down . As a result of deforestation , only 6.2 e6km2 remain of the original 16 e6km2 of forest that formerly covered the Earth . |
1482 | Hockey_stick_controversy | 18 proxies tell us the world was the same or warmer 1,000 years ago. | 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 . |
3121 | Models_of_communication | "Cloud cover in models is poorly treated and inaccurately predicted. | Models of communication Models of communication are conceptual models used to explain the human communication process . The first major model for communication came in 1948 by Claude Elwood Shannon and published with an introduction by Warren Weaver for Bell Laboratories . Following the basic concept , communication is the process of sending and receiving messages or transferring information from one part ( sender ) to another ( receiver ) . |
1307 | Scientific_consensus_on_climate_change | a new study by scientists at the Australian Research Council finds that the ongoing bleaching event is mainly due to human-caused global warming, and that if global warming proceeds as currently expected, "large parts" of the Great Barrier Reef could die by the mid-2030s. | 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. |
2605 | United_Nations_Development_Programme | "A United Nations report has identified the world's rapidly growing herds of cattle as the greatest threat to the climate, forests and wildlife. ... | United Nations Development Programme The United Nations Development Programme ( UNDP ) is the United Nations ' global development network . Headquartered in New York City , UNDP advocates for change and connects countries to knowledge , experience and resources to help people build a better life . It provides expert advice , training and grants support to developing countries , with increasing emphasis on assistance to the least developed countries . The status of UNDP is that of an executive board within the United Nations General Assembly . The UNDP Administrator is the third highest-ranking official of the United Nations after the United Nations Secretary-General and Deputy Secretary-General . To accomplish the MDGs and encourage global development , UNDP focuses on poverty reduction , HIV/AIDS , democratic governance , energy and environment , social development , and crisis prevention and recovery . UNDP also encourages the protection of human rights and the empowerment of women in all of its programmes . The UNDP Human Development Report Office also publishes an annual Human Development Report ( since 1990 ) to measure and analyse developmental progress . In addition to a global Report , UNDP publishes regional , national , and local Human Development Reports . UNDP is funded entirely by voluntary contributions from member nations . The organization operates in 177 countries , where it works with local governments to meet development challenges and develop local capacity . Additionally , the UNDP works internationally to help countries achieve the Millennium Development Goals ( MDGs ) . Currently , the UNDP is one of the main UN agencies involved in the development of the Post-2015 Development Agenda . UNDP works with nations on their own solutions to global and national development challenges . As they develop local capacity , they draw on the people of UNDP and its wide range of partners . |
434 | Climate_variability | It's also a sufficiently long period to include several cycles of climate variability. | Climate variability Climate variability includes all the variations in the climate that last longer than individual weather events, whereas the term climate change only refers to those variations that persist for a longer period of time, typically decades or more. In the time since the industrial revolution the climate has increasingly been affected by human activities that are causing global warming and climate change.The climate system receives nearly all of its energy from the sun. The climate system also radiates energy to outer space. The balance of incoming and outgoing energy, and the passage of the energy through the climate system, determines Earth's energy budget. When the incoming energy is greater than the outgoing energy, earth's energy budget is positive and the climate system is warming. If more energy goes out, the energy budget is negative and earth experiences cooling. The energy moving through Earth's climate system finds expression in weather, varying on geographic scales and time. Long-term averages and variability of weather in a region constitute the region's climate. Such changes can be the result of "internal variability", when natural processes inherent to the various parts of the climate system alter the distribution of energy. Examples include variability in ocean basins such as the Pacific decadal oscillation and Atlantic multidecadal oscillation. Climate variability can also result from external forcing, when events outside of the climate system's components nonetheless produce changes within the system. Examples include changes in solar output and volcanism. Climate variability has consequences for sea level changes, plant life, and mass extinctions; it also affects human societies. |
2997 | Greenhouse_gas | The trend in CO2 at Mauna Loa is practically identical to the global trend because CO2 mixes well throughout the atmosphere. | Greenhouse gas A greenhouse gas ( abbrev . GHG ) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range . This process is the fundamental cause of the greenhouse effect . The primary greenhouse gases in Earth 's atmosphere are water vapor , carbon dioxide , methane , nitrous oxide , and ozone . Without greenhouse gases , the average temperature of Earth 's surface would be about -18 ° C , rather than the present average of 15 ° C . In the Solar System , the atmospheres of Venus , Mars and Titan also contain gases that cause a greenhouse effect . Human activities since the beginning of the Industrial Revolution ( taken as the year 1750 ) have produced a 40 % increase in the atmospheric concentration of carbon dioxide , from 280 ppm in 1750 to 406 ppm in early 2017 . This increase has occurred despite the uptake of a large portion of the emissions by various natural `` sinks '' involved in the carbon cycle . Anthropogenic carbon dioxide emissions ( i.e. , emissions produced by human activities ) come from combustion of fossil fuels , principally coal , oil , and natural gas , along with deforestation , soil erosion and animal agriculture . It has been estimated that if greenhouse gas emissions continue at the present rate , Earth 's surface temperature could exceed historical values as early as 2047 , with potentially harmful effects on ecosystems , biodiversity and the livelihoods of people worldwide . Recent estimates suggest that on the current emissions trajectory the Earth could pass a threshold of 2 ° C global warming , which the United Nations ' IPCC designated as the upper limit to avoid `` dangerous '' global warming , by 2036 . |
1434 | Amazon_rainforest | Just 0.7% of the world's forests are coastal mangroves, yet they store up to 10 times as much carbon per hectare as tropical forests. | Amazon rainforest The Amazon rainforest ( Portuguese : Floresta Amazônica or Amazônia ; Selva Amazónica , Amazonía or usually Amazonia ; Forêt amazonienne Amazoneregenwoud ) , also known in English as Amazonia or the Amazon Jungle , is a moist broadleaf forest in the Amazon biome that covers most of the Amazon basin of South America . This basin encompasses 7,000,000 km2 , of which 5,500,000 km2 are covered by the rainforest . This region includes territory belonging to nine nations . The majority of the forest is contained within Brazil , with 60 % of the rainforest , followed by Peru with 13 % , Colombia with 10 % , and with minor amounts in Venezuela , Ecuador , Bolivia , Guyana , Suriname and French Guiana . States or departments in four nations contain `` Amazonas '' in their names . The Amazon represents over half of the planet 's remaining rainforests , and comprises the largest and most biodiverse tract of tropical rainforest in the world , with an estimated 390 billion individual trees divided into 16,000 species . |
1866 | Climate_change_and_agriculture | Climate scientists have predicted global temperatures would increase more than one degree Celsius by 2020," but observed temperatures have been only half as high. | Climate change and agriculture -RSB- Climate change and agriculture are interrelated processes , both of which take place on a global scale . Climate change affects agriculture in a number of ways , including through changes in average temperatures , rainfall , and climate extremes ( e.g. , heat waves ) ; changes in pests and diseases ; changes in atmospheric carbon dioxide and ground-level ozone concentrations ; changes in the nutritional quality of some foods ; and changes in sea level . Climate change is already affecting agriculture , with effects unevenly distributed across the world . Future climate change will likely negatively affect crop production in low latitude countries , while effects in northern latitudes may be positive or negative . Climate change will probably increase the risk of food insecurity for some vulnerable groups , such as the poor . Agriculture contributes to climate change by ( 1 ) anthropogenic emissions of greenhouse gases ( GHGs ) , and ( 2 ) by the conversion of non-agricultural land ( e.g. , forests ) into agricultural land . Agriculture , forestry and land-use change contributed around 20 to 25 % to global annual emissions in 2010 . There are a range of policies that can reduce the risk of negative climate change impacts on agriculture , and to reduce GHG emissions from the agriculture sector . |
1061 | Retreat_of_glaciers_since_1850 | warmer oceans have also begun to destabilize glaciers in Greenland and Antarctica | Retreat of glaciers since 1850 The retreat of glaciers since 1850 affects the availability of fresh water for irrigation and domestic use , mountain recreation , animals and plants that depend on glacier-melt , and , in the longer term , the level of the oceans . Studied by glaciologists , the temporal coincidence of glacier retreat with the measured increase of atmospheric greenhouse gases is often cited as an evidentiary underpinning of global warming . Mid-latitude mountain ranges such as the Himalayas , Alps , Rocky Mountains , Cascade Range , and the southern Andes , as well as isolated tropical summits such as Mount Kilimanjaro in Africa , are showing some of the largest proportionate glacial losses . Glacier mass balance is the key determinant of the health of a glacier . If the amount of frozen precipitation in the accumulation zone exceeds the quantity of glacial ice lost due to melting or in the ablation zone a glacier will advance ; if the accumulation is less than the ablation , the glacier will retreat . Glaciers in retreat will have negative mass balances , and if they do not find an equilibrium between accumulation and ablation , will eventually disappear . The Little Ice Age was a period from about 1550 to 1850 when the world experienced relatively cooler temperatures compared to the present . Subsequently , until about 1940 , glaciers around the world retreated as the climate warmed substantially . Glacial retreat slowed and even reversed temporarily , in many cases , between 1950 and 1980 as global temperatures cooled slightly . Since 1980 , a significant global warming has led to glacier retreat becoming increasingly rapid and ubiquitous , so much so that some glaciers have disappeared altogether , and the existences of many of the remaining glaciers are threatened . In locations such as the Andes of South America and Himalayas in Asia , the demise of glaciers in these regions has the potential to affect water supplies in those areas . The retreat of mountain glaciers , notably in western North America , Asia , the Alps and tropical and subtropical regions of South America , Africa and Indonesia , provide evidence for the rise in global temperatures since the late 19th century . The acceleration of the rate of retreat since 1995 of key outlet glaciers of the Greenland and West Antarctic ice sheets may foreshadow a rise in sea level , which would affect coastal regions . |
2565 | An_Inconvenient_Truth | Human kind has little or nothing to do with the recent temperature changes. | An Inconvenient Truth An Inconvenient Truth is a 2006 American documentary film directed by Davis Guggenheim about former United States Vice President Al Gore 's campaign to educate citizens about global warming via a comprehensive slide show that , by his own estimate made in the film , he has given more than a thousand times . The idea to document his efforts came from producer Laurie David , who saw his presentation at a town-hall meeting on global warming , which coincided with the opening of The Day After Tomorrow . Laurie David was so inspired by Gore 's slide show that she , with producer Lawrence Bender , met with Guggenheim to adapt the presentation into a film . Premiering at the 2006 Sundance Film Festival and opening in New York City and Los Angeles on May 24 , 2006 , the documentary was a critical and box office success , winning two Academy Awards for Best Documentary Feature and Best Original Song . The film grossed $ 24 million in the U.S. and $ 26 million at the international box office , becoming the tenth highest grossing documentary film to date in the United States . Since the film 's release , An Inconvenient Truth has been credited for raising international public awareness of global warming and reenergizing the environmental movement . The documentary has also been included in science curricula in schools around the world , which has spurred some controversy . A sequel to the film , titled An Inconvenient Sequel : Truth to Power , will be released on July 28 , 2017 . |
1299 | Global_warming | A recent Nature study expecting more severe hurricanes from global warming still found that damages would halve from 0.04 per cent to 0.02 per cent of global GDP, because the increased ferocity would be more than made up by increased prosperity and resilience. | 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 . |
3008 | Atlantic_Ocean | However, more direct comparisons between solar activity and global temperature finds that as the sun grew hotter or cooler, Earth's climate followed it with a 10 year lag - presumably due to the dampening effect of the ocean. | Atlantic Ocean The Atlantic Ocean is the second largest of the world 's oceans with a total area of about 106,460,000 km2 . It covers approximately 20 percent of the Earth 's surface and about 29 percent of its water surface area . It separates the `` Old World '' from the `` New World '' . The Atlantic Ocean occupies an elongated , S-shaped basin extending longitudinally between Eurasia and Africa to the east , and the Americas to the west . As one component of the interconnected global ocean , it is connected in the north to the Arctic Ocean , to the Pacific Ocean in the southwest , the Indian Ocean in the southeast , and the Southern Ocean in the south ( other definitions describe the Atlantic as extending southward to Antarctica ) . The Equatorial Counter Current subdivides it into the North Atlantic Ocean and South Atlantic Ocean at about 8 ° N. Scientific explorations of the Atlantic include the Challenger expedition , the German Meteor expedition , Columbia University 's Lamont-Doherty Earth Observatory and the United States Navy Hydrographic Office . |
656 | Climate_change_feedback | The Arctic's carbon bomb might be even more potent than we thought […] methane, a shorter-lived but far harder-hitting gas that could cause faster bursts of warming | Climate change feedback Climate change feedback is important in the understanding of global warming because feedback processes may amplify or diminish the effect of each climate forcing , and so play an important part in determining the climate sensitivity and future climate state . Feedback in general is the process in which changing one quantity changes a second quantity , and the change in the second quantity in turn changes the first . Positive feedback amplifies the change in the first quantity while negative feedback reduces it . The term `` forcing '' means a change which may `` push '' the climate system in the direction of warming or cooling . An example of a climate forcing is increased atmospheric concentrations of greenhouse gases . By definition , forcings are external to the climate system while feedbacks are internal ; in essence , feedbacks represent the internal processes of the system . Some feedbacks may act in relative isolation to the rest of the climate system ; others may be tightly coupled ; hence it may be difficult to tell just how much a particular process contributes . Forcings , feedbacks and the dynamics of the climate system determine how much and how fast the climate changes . The main positive feedback in global warming is the tendency of warming to increase the amount of water vapor in the atmosphere , which in turn leads to further warming . The main negative feedback comes from the Stefan -- Boltzmann law , the amount of heat radiated from the Earth into space changes with the fourth power of the temperature of Earth 's surface and atmosphere . Some observed and potential effects of global warming are positive feedbacks , which contribute directly to further global warming . The Intergovernmental Panel on Climate Change 's ( IPCC ) Fourth Assessment Report states that `` Anthropogenic warming could lead to some effects that are abrupt or irreversible , depending upon the rate and magnitude of the climate change . '' |
920 | Antarctica | If those emissions continue unchecked and the world is allowed to heat up enough, scientists have no doubt that large parts of Antarctica will melt into the sea. | Antarctica Antarctica ( UK English -LSB- ænˈtɑːktɪkə -RSB- or -LSB- ænˈtɑːtɪkə -RSB- , US English -LSB- æntˈɑːrktɪkə -RSB- ) is Earth 's southernmost continent . It contains the geographic South Pole and is situated in the Antarctic region of the Southern Hemisphere , almost entirely south of the Antarctic Circle , and is surrounded by the Southern Ocean . At 14000000 km2 , it is the fifth-largest continent . For comparison , Antarctica is nearly twice the size of Australia . About 98 % of Antarctica is covered by ice that averages 1.9 km in thickness , which extends to all but the northernmost reaches of the Antarctic Peninsula . Antarctica , on average , is the coldest , driest , and windiest continent , and has the highest average elevation of all the continents . Antarctica is a desert , with annual precipitation of only 200 mm ( 8 in ) along the coast and far less inland . The temperature in Antarctica has reached − 89.2 ° C ( − 128.6 ° F ) , though the average for the third quarter ( the coldest part of the year ) is − 63 ° C ( − 81 ° F ) . Anywhere from 1,000 to 5,000 people reside throughout the year at the research stations scattered across the continent . Organisms native to Antarctica include many types of algae , bacteria , fungi , plants , protista , and certain animals , such as mites , nematodes , penguins , seals and tardigrades . Vegetation , where it occurs , is tundra . Although myths and speculation about a Terra Australis ( `` Southern Land '' ) date back to antiquity , Antarctica is noted as the last region on Earth in recorded history to be discovered and colonised by humans , being only first sighted in 1820 by the Russian expedition of Fabian Gottlieb von Bellingshausen and Mikhail Lazarev on Vostok and Mirny , who sighted the Fimbul ice shelf . The continent , however , remained largely neglected for the rest of the 19th century because of its hostile environment , lack of easily accessible resources , and isolation . In 1895 , the first confirmed landing was conducted by a team of Norwegians . Antarctica is a de facto condominium , governed by parties to the Antarctic Treaty System that have consulting status . Twelve countries signed the Antarctic Treaty in 1959 , and thirty-eight have signed it since then . The treaty prohibits military activities and mineral mining , prohibits nuclear explosions and nuclear waste disposal , supports scientific research , and protects the continent 's ecozone . Ongoing experiments are conducted by more than 4,000 scientists from many nations . |
2178 | Global_warming | Loehle and Scafetta find a 60 year cycle causing 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 . |
2523 | Earth | This is called the "atmospheric greenhouse effect", and without it the Earth's surface would be much colder. | 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 . |
320 | 20th_century | Globally averaged thermometers show two periods of warming since 1900: a half-degree from natural causes in the first half of the 20th century, before there was an increase in industrial carbon dioxide that was enough to produce it, and another half-degree in the last quarter of the century. | 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 ) . |
578 | Carbon_dioxide_in_Earth's_atmosphere | 'If we do nothing to reduce our greenhouse gas emissions, the kind of extreme heat we saw this past summer will be the norm when my young son is a grown man.' | Carbon dioxide in Earth's atmosphere Carbon dioxide is an important trace gas in Earth 's atmosphere . Currently it constitutes about 0.041 % ( equal to 410 parts per million ; ppm ) by volume of the atmosphere . Despite its relatively small concentration is a potent greenhouse gas and plays a vital role in regulating Earth 's surface temperature through radiative forcing and the greenhouse effect . Reconstructions show that concentrations of in the atmosphere have varied , ranging from as high as 7,000 ppm during the Cambrian period about 500 million years ago to as low as 180 ppm during the Quaternary glaciation of the last two million years . Carbon dioxide is an integral part of the carbon cycle , a biogeochemical cycle in which carbon is exchanged between the Earth 's oceans , soil , rocks and the biosphere . Plants and other photoautotrophs use solar energy to produce carbohydrate from atmospheric carbon dioxide and water by photosynthesis . Almost all other organisms depend on carbohydrate derived from photosynthesis as their primary source of energy and carbon compounds . The current episode of global warming is attributed to increasing emissions of and other greenhouse gases into Earth 's atmosphere . The global annual mean concentration of in the atmosphere has increased by more than 40 % since the start of the Industrial Revolution , from 280 ppm , the level it had for the last 10,000 years leading up to the mid-18th century , to 399 ppm as of 2015 . The present concentration is the highest in at least the past 800,000 years and likely the highest in the past 20 million years . The increase has been caused by anthropogenic sources , particularly the burning of fossil fuels and deforestation . The daily average concentration of atmospheric CO2 at Mauna Loa Observatory first exceeded 400 ppm on 10 May 2013 . It is currently rising at a rate of approximately 2 ppm/year and accelerating . An estimated 30 -- 40 % of the released by humans into the atmosphere dissolves into oceans , rivers and lakes , which contributes to ocean acidification . |
1268 | Sea_level_rise | The thermal expansion of the oceans, compounded by melting glaciers, resulted in the highest global sea level on record in 2015. | 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 . |
10 | Ocean_acidification | Human additions of CO2 are in the margin of error of current measurements and the gradual increase in CO2 is mainly from oceans degassing as the planet slowly emerges from the last ice age. | Ocean acidification Ocean acidification is the ongoing decrease in the pH of the Earth 's oceans , caused by the uptake of carbon dioxide from the atmosphere . Seawater is slightly basic ( meaning pH > 7 ) , and the process in question is a shift towards pH-neutral conditions rather than a transition to acidic conditions ( pH < 7 ) . Ocean alkalinity is not changed by the process , or may increase over long time periods due to carbonate dissolution . An estimated 30 -- 40 % of the carbon dioxide from human activity released into the atmosphere dissolves into oceans , rivers and lakes . To achieve chemical equilibrium , some of it reacts with the water to form carbonic acid . Some of these extra carbonic acid molecules react with a water molecule to give a bicarbonate ion and a hydronium ion , thus increasing ocean acidity ( H + ion concentration ) . Between 1751 and 1996 surface ocean pH is estimated to have decreased from approximately 8.25 to 8.14 , representing an increase of almost 35 % in H + ion concentration in the world 's oceans . Earth System Models project that within the last decade ocean acidity exceeded historical analogues and in combination with other ocean biogeochemical changes could undermine the functioning of marine ecosystems and disrupt the provision of many goods and services associated with the ocean . Increasing acidity is thought to have a range of potentially harmful consequences for marine organisms , such as depressing metabolic rates and immune responses in some organisms , and causing coral bleaching . By increasing the presence of free hydrogen ions , each molecule of carbonic acid that forms in the oceans ultimately results in the conversion of two carbonate ions into bicarbonate ions . This net decrease in the amount of carbonate ions available makes it more difficult for marine calcifying organisms , such as coral and some plankton , to form biogenic calcium carbonate , and such structures become vulnerable to dissolution . Ongoing acidification of the oceans threatens food chains connected with the oceans . As members of the InterAcademy Panel , 105 science academies have issued a statement on ocean acidification recommending that by 2050 , global emissions be reduced by at least 50 % compared to the 1990 level . While ongoing ocean acidification is anthropogenic in origin , it has occurred previously in Earth 's history . The most notable example is the Paleocene-Eocene Thermal Maximum ( PETM ) , which occurred approximately 56 million years ago . For reasons that are currently uncertain , massive amounts of carbon entered the ocean and atmosphere , and led to the dissolution of carbonate sediments in all ocean basins . Ocean acidification has been called the `` evil twin of global warming '' and `` the other problem '' . |
2607 | Greenhouse_gas | Burning fuel to produce fertiliser to grow feed, to produce meat and to transport it - and clearing vegetation for grazing - produces 9 per cent of all emissions of carbon dioxide, the most common greenhouse gas. | 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 . |
1786 | Greenhouse_gas | CFCs contribute to global waerming at a small level. | 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 . |
1963 | Coal | Tallahassee reduced its carbon intensity by roughly 40 percent. | Coal Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams . The harder forms , such as anthracite coal , can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure . Coal is composed primarily of carbon , along with variable quantities of other elements , chiefly hydrogen , sulfur , oxygen , and nitrogen . A fossil fuel , coal forms when dead plant matter is converted into peat , which in turn is converted into lignite , then sub-bituminous coal , after that bituminous coal , and lastly anthracite . This involves biological and geological processes that take place over time . Throughout human history , coal has been used as an energy resource , primarily burned for the production of electricity and heat , and is also used for industrial purposes , such as refining metals . Coal is the largest source of energy for the generation of electricity worldwide , as well as one of the largest worldwide anthropogenic sources of carbon dioxide releases . The extraction of coal , its use in energy production and its byproducts are all associated with environmental and health effects including climate change . Coal is extracted from the ground by coal mining . Since 1983 , the world 's top coal producer has been China . In 2015 China produced 3,747 million tonnes of coal -- 47.7 % of 7,861 million tonnes world coal production . In 2015 other large producers were United States ( 813 million tonnes ) , India ( 678 ) , European Union ( 539 ) and Australia ( 503 ) . In 2010 the largest exporters were Australia with 328 million tonnes ( 27.1 % of world coal export ) and Indonesia with 316 million tonnes ( 26.1 % ) , while the largest importers were Japan with 207 million tonnes ( 17.5 % of world coal import ) , China with 195 million tonnes ( 16.6 % ) and South Korea with 126 million tonnes ( 10.7 % ) . |
319 | Low-pressure_area | Most of the atmospheric moisture originates in the tropical ocean, and the difference between surface and upper atmospheric temperature determines how much of the moisture rises into the atmosphere. | Low-pressure area A low-pressure area , low , or depression is a region where the topographic map is atmospheric pressure is lower than that of surrounding locations . Low-pressure systems form under areas of wind divergence that occur in the upper levels of the troposphere . The formation process of a low-pressure area is known as cyclogenesis . Within the field of meteorology , atmospheric divergence aloft occurs in two areas . The first area is on the east side of upper troughs , which form half of a Rossby wave within the Westerlies ( a trough with large wavelength that extends through the troposphere ) . A second area of wind divergence aloft occurs ahead of embedded shortwave troughs , which are of smaller wavelength . Diverging winds aloft ahead of these troughs cause atmospheric lift within the troposphere below , which lowers surface pressures as upward motion partially counteracts the force of gravity . Thermal lows form due to localized heating caused by greater sunshine over deserts and other land masses . Since localized areas of warm air are less dense than their surroundings , this warmer air rises , which lowers atmospheric pressure near that portion of the Earth 's surface . Large-scale thermal lows over continents help drive monsoon circulations . Low-pressure areas can also form due to organized thunderstorm activity over warm water . When this occurs over the tropics in concert with the Intertropical Convergence Zone , it is known as a monsoon trough . Monsoon troughs reach their northerly extent in August and their southerly extent in February . When a convective low acquires a well-hot circulation in the tropics it is termed a tropical cyclone . Tropical cyclones can form during any month of the year globally , but can occur in either the northern or southern hemisphere during November . Atmospheric lift will also generally produce cloud cover through adiabatic cooling once the air becomes saturated as it rises , although the low-pressure area typically brings cloudy skies , which act to minimize diurnal temperature extremes . Since clouds reflect sunlight , incoming shortwave solar radiation decreases , which causes lower temperatures during the day . At night the absorptive effect of clouds on outgoing longwave radiation , such as heat energy from the surface , allows for warmer diurnal low temperatures in all seasons . The stronger the area of low pressure , the stronger the winds experienced in its vicinity . Globally , low-pressure systems are most frequently located over the Tibetan Plateau and in the lee of the Rocky mountains . In Europe ( particularly in the United Kingdom ) , recurring low-pressure weather systems are typically known as `` depressions '' . |
1970 | Carbon_tax | The Business Council, the Minerals Council, the Australian Industry Group, the Australian Chamber of Commerce and Industry, have all called for the [carbon] tax to be repealed. | 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 . |
82 | Greenhouse_gas | The atmospheric residency time of carbon dioxide is five years | 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 . |
2907 | Ice_age | 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. | 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 . |
349 | Physical_impacts_of_climate_change | Nor is there evidence of an increase in floods globally. | 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 . |
443 | Scientific_consensus_on_climate_change | "Today climate scientists are obsessed with the level of carbon dioxide in the atmosphere, a very very small part of the overall picture. | 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. |
1576 | Solar_cycle | Solar cycles cause global warming. | Solar cycle The solar cycle or solar magnetic activity cycle is the nearly periodic 11-year change in the Sun 's activity ( including changes in the levels of solar radiation and ejection of solar material ) and appearance ( changes in the number and size of sunspots , flares , and other manifestations ) . They have been observed ( by changes in the sun 's appearance and by changes seen on Earth , such as auroras ) for centuries . The changes on the sun cause effects in space , in the atmosphere , and on Earth 's surface . While it is the dominant variable in solar activity , aperiodic fluctuations also occur . |
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