Datasets:

inpars
/

fewshot-examples

Dataset card Data Studio Files Files and versions Community

Split (1)

train · 1.06M rows

query_id stringlengths 1 41	doc_id stringlengths 1 109	query stringlengths 2 5.5k	document stringlengths 0 122k
830	Space_and_survival	parts of the Earth will likely become close to uninhabitable	Space and survival Space and survival refers to the idea that the long-term survival of the human species and civilization requires proper use of the resources of outer space and the need for space colonization and space science . The concept posits that inaction could lead to human extinction . A related observation is that limited time and resources may be available for the colonization of space . Various scenarios for human survival have been discussed in science and popular culture , particularly humanity 's prospects after catastrophic events in the solar system and factors that could help or hinder survival . The earliest appearance of a connection between space exploration and human survival appears in Louis J. Halle 's 1980 article in Foreign Affairs , in which he stated colonization of space will keep humanity safe should global nuclear warfare occur . This idea has received more attention in recent years as advancing technology makes cheap space travel more feasible .
1503	Climate	climate models have overestimated the amount of global warming and failed to predict what climatologists call the warming 'hiatus'.	Climate Climate is the statistics of weather , usually over a 30-year interval . It is measured by assessing the patterns of variation in temperature , humidity , atmospheric pressure , wind , precipitation , atmospheric particle count and other meteorological variables in a given region over long periods of time . Climate differs from weather , in that weather only describes the short-term conditions of these variables in a given region . A region 's climate is generated by the climate system , which has five components : atmosphere , hydrosphere , cryosphere , lithosphere , and biosphere . The climate of a location is affected by its latitude , terrain , and altitude , as well as nearby water bodies and their currents . Climates can be classified according to the average and the typical ranges of different variables , most commonly temperature and precipitation . The most commonly used classification scheme was the Köppen climate classification . The Thornthwaite system , in use since 1948 , incorporates evapotranspiration along with temperature and precipitation information and is used in studying biological diversity and how climate change affects it . The Bergeron and Spatial Synoptic Classification systems focus on the origin of air masses that define the climate of a region . Paleoclimatology is the study of ancient climates . Since direct observations of climate are not available before the 19th century , paleoclimates are inferred from proxy variables that include non-biotic evidence such as sediments found in lake beds and ice cores , and biotic evidence such as tree rings and coral . Climate models are mathematical models of past , present and future climates . Climate change may occur over long and short timescales from a variety of factors ; recent warming is discussed in global warming . Global warming results in redistributions . For example , `` a 3 ° C change in mean annual temperature corresponds to a shift in isotherms of approximately 300 -- 400 km in latitude ( in the temperate zone ) or 500 m in elevation . Therefore , species are expected to move upwards in elevation or towards the poles in latitude in response to shifting climate zones '' .
2813	Climate_sensitivity	In fact, the authors go on to estimate climate sensitivity from their findings, calculate a value between 2.3 to 4.1°C.	Climate sensitivity Climate sensitivity is the equilibrium temperature change in response to changes of the radiative forcing . Therefore , climate sensitivity depends on the initial climate state , but potentially can be accurately inferred from precise palaeoclimate data . Slow climate feedbacks , especially changes of ice sheet size and atmospheric CO2 , amplify the total Earth system sensitivity by an amount that depends on the time scale considered . Although climate sensitivity is usually used in the context of radiative forcing by carbon dioxide ( CO2 ) , it is thought of as a general property of the climate system : the change in surface air temperature ( ΔTs ) following a unit change in radiative forcing ( RF ) , and thus is expressed in units of ° C / ( W/m2 ) . For this to be useful , the measure must be independent of the nature of the forcing ( e.g. from greenhouse gases or solar variation ) ; to first order this is indeed found to be so . The climate sensitivity specifically due to is often expressed as the temperature change in ° C associated with a doubling of the concentration of carbon dioxide in Earth 's atmosphere . For coupled atmosphere-ocean global climate models ( e.g. CMIP5 ) the climate sensitivity is an emergent property : it is not a model parameter , but rather a result of a combination of model physics and parameters . By contrast , simpler energy-balance models may have climate sensitivity as an explicit parameter . The terms represented in the equation relate radiative forcing ( RF ) to linear changes in global surface temperature change ( ΔTs ) via the climate sensitivity λ . It is also possible to estimate climate sensitivity from observations ; however , this is difficult due to uncertainties in the forcing and temperature histories .
1010	El_Niño	"'The Arctic may be remote, but changes that occur there directly affect us.	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 '' .
436	Australia	The unusual heat was most noteworthy in Europe, which had its warmest April on record, and Australia, which had its second-warmest.	Australia Australia ( -LSB- əˈstreɪliə -RSB- , -LSB- ɒ - -RSB- , -LSB- - ljə -RSB- ) , officially the Commonwealth of Australia , is a country comprising the mainland of the Australian continent , the island of Tasmania and numerous smaller islands . It is the world 's sixth-largest country by total area . The neighbouring countries are Papua New Guinea , Indonesia and East Timor to the north ; the Solomon Islands and Vanuatu to the north-east ; and New Zealand to the south-east . Australia 's capital is Canberra , and its largest urban area is Sydney . For about 50,000 years before the first British settlement in the late 18th century , Australia was inhabited by indigenous Australians , who spoke languages classifiable into roughly 250 groups . After the European discovery of the continent by Dutch explorers in 1606 , Australia 's eastern half was claimed by Great Britain in 1770 and initially settled through penal transportation to the colony of New South Wales from 26 January 1788 . The population grew steadily in subsequent decades , and by the 1850s most of the continent had been explored and an additional five self-governing crown colonies established . On 1 January 1901 , the six colonies federated , forming the Commonwealth of Australia . Australia has since maintained a stable liberal democratic political system that functions as a federal parliamentary constitutional monarchy comprising six states and several territories . The population of 24 million is highly urbanised and heavily concentrated on the eastern seaboard . Australia has the world 's 13th-largest economy and ninth-highest per capita income ( IMF ) . With the second-highest human development index globally , the country ranks highly in quality of life , health , education , economic freedom , and civil liberties and political rights . Australia is a member of the United Nations , G20 , Commonwealth of Nations , ANZUS , Organisation for Economic Co-operation and Development ( OECD ) , World Trade Organization , Asia-Pacific Economic Cooperation , and the Pacific Islands Forum .
849	Eocene	The most notorious was 252 million years ago; it began when carbon warmed the planet by five degrees, accelerated when that warming triggered the release of methane in the Arctic, and ended with 97 percent of all life on Earth dead."	Eocene The Eocene ( -LSB- pronˈiːəˌsiːn , _ ˈiːoʊ - -RSB- ) Epoch , lasting from , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era . The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch . The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C . The end is set at a major extinction event called the Grande Coupure ( the `` Great Break '' in continuity ) or the Eocene -- Oligocene extinction event , which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay . As with other geologic periods , the strata that define the start and end of the epoch are well identified , though their exact dates are slightly uncertain . The name Eocene comes from the Ancient Greek ἠώς ( ēṓs , `` dawn '' ) and καινός ( kainós , `` new '' ) and refers to the `` dawn '' of modern ( ` new ' ) fauna that appeared during the epoch .
648	Carnivorous_plant	'there will not be enough nitrogen available to sustain the high carbon uptake scenarios.'	Carnivorous plant Carnivorous plants are plants that derive some or most of their nutrients ( but not energy ) from trapping and consuming animals or protozoans , typically insects and other arthropods . Carnivorous plants have adapted to grow in places where the soil is thin or poor in nutrients , especially nitrogen , such as acidic bogs and rock outcroppings . Charles Darwin wrote Insectivorous Plants , the first well-known treatise on carnivorous plants , in 1875 . True carnivory is thought to have evolved independently nine times in five different orders of flowering plants , and is represented by more than a dozen genera . This classification includes at least 583 species that attract , trap and kill prey , absorbing the resulting available nutrients . Additionally , over 300 protocarnivorous plant species in several genera show some but not all of these characteristics .
516	Global_warming	For the past 4567 million years, the sun and the Earth's orbit have driven climate change cycles.	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 .
1028	The_Wizard_of_Oz_(1939_film)	A second coat of paint has much less of an effect, while adding a third or fourth coat has almost no impact at all."	The Wizard of Oz (1939 film) The Wizard of Oz is a 1939 American musical fantasy comedy-drama film produced by Metro-Goldwyn-Mayer , and the best-known and most commercially successful adaptation based on the 1900 novel The Wonderful Wizard of Oz by L. Frank Baum . The film stars Judy Garland as Dorothy Gale . The co-stars are Ray Bolger , Jack Haley , Bert Lahr , Frank Morgan , Billie Burke , and Margaret Hamilton , with Charley Grapewin , Pat Walshe and Clara Blandick , Terry the dog ( billed as Toto ) , and the Singer Midgets as the Munchkins . Notable for its use of Technicolor , fantasy storytelling , musical score , and unusual characters , over the years it has become an icon of American popular culture . It was nominated for six Academy Awards , including Best Picture , but lost to Gone with the Wind . It did win in two other categories , including Best Original Song for `` Over the Rainbow '' and Best Original Score by Herbert Stothart . However , the film was a box office disappointment on its initial release , earning only $ 3,017,000 on a $ 2,777,000 budget , despite receiving largely positive reviews . It was MGM 's most expensive production to date and did not completely recoup the studio 's investment nor turn a profit until theatrical re-releases starting in 1949 . The 1956 broadcast television premiere of the film on the CBS network reintroduced the film to the wider public and eventually made the presentation an annual tradition , making it one of the best known films in movie history . The film was named the most-viewed motion picture on television syndication by the Library of Congress , which also included the film in its National Film Registry in its inaugural year in 1989 . Designation on the registry calls for efforts to preserve it for being `` culturally , historically , and aesthetically significant '' . It is also one of the few films on UNESCO 's Memory of the World Register . The Wizard of Oz is often ranked on best-movie lists in critics ' and public polls . It is the source of many quotes referenced in contemporary popular culture . It was directed primarily by Victor Fleming ( who left production to take over direction on the troubled Gone with the Wind production ) . Noel Langley , Florence Ryerson , and Edgar Allan Woolf received credit for the screenplay , but uncredited contributions were made by others . The songs were written by Edgar `` Yip '' Harburg ( lyrics ) and Harold Arlen ( music ) . The musical score and the incidental music were composed by Stothart .
2623	Atmosphere_of_Jupiter	(2009) have demonstrated recently – the upper troposphere (the only place where adding CO2 to the atmosphere could make any difference to temperature) is considerably drier than the models are tuned to expect."	Atmosphere of Jupiter The atmosphere of Jupiter is the largest planetary atmosphere in the Solar System . It is mostly made of molecular hydrogen and helium in roughly solar proportions ; other chemical compounds are present only in small amounts and include methane , ammonia , hydrogen sulfide and water . Although water is thought to reside deep in the atmosphere , its directly measured concentration is very low . The nitrogen , sulfur , and noble gas abundances in Jupiter 's atmosphere exceed solar values by a factor of about three . The atmosphere of Jupiter lacks a clear lower boundary and gradually transitions into the liquid interior of the planet . From lowest to highest , the atmospheric layers are the troposphere , stratosphere , thermosphere and exosphere . Each layer has characteristic temperature gradients . The lowest layer , the troposphere , has a complicated system of clouds and hazes , comprising layers of ammonia , ammonium hydrosulfide and water . The upper ammonia clouds visible at Jupiter 's surface are organized in a dozen zonal bands parallel to the equator and are bounded by powerful zonal atmospheric flows ( winds ) known as jets . The bands alternate in color : the dark bands are called belts , while light ones are called zones . Zones , which are colder than belts , correspond to upwellings , while belts mark descending air . The zones ' lighter color is believed to result from ammonia ice ; what gives the belts their darker colors is uncertain . The origins of the banded structure and jets are not well understood , though a `` shallow model '' and a `` deep model '' exist . The Jovian atmosphere shows a wide range of active phenomena , including band instabilities , vortices ( cyclones and anticyclones ) , storms and lightning . The vortices reveal themselves as large red , white or brown spots ( ovals ) . The largest two spots are the Great Red Spot ( GRS ) and Oval BA , which is also red . These two and most of the other large spots are anticyclonic . Smaller anticyclones tend to be white . Vortices are thought to be relatively shallow structures with depths not exceeding several hundred kilometers . Located in the southern hemisphere , the GRS is the largest known vortex in the Solar System . It could engulf two or three Earths and has existed for at least three hundred years . Oval BA , south of GRS , is a red spot a third the size of GRS that formed in 2000 from the merging of three white ovals . Jupiter has powerful storms , often accompanied by lightning strikes . The storms are a result of moist convection in the atmosphere connected to the evaporation and condensation of water . They are sites of strong upward motion of the air , which leads to the formation of bright and dense clouds . The storms form mainly in belt regions . The lightning strikes on Jupiter are hundreds of times more powerful than those seen on Earth . However , there are so few , that the amount of lightning activity is comparable to Earth .
1799	Satellite_television	Satellite transmissions are extremely small and irrelevant.	Satellite television Satellite television is a service that delivers television programming to customers by relaying it from a communications satellite orbiting the Earth directly to the customer 's location . The signals are received via an outdoor parabolic antenna usually referred to as a satellite dish and a low-noise block downconverter . A satellite receiver then decodes the desired television programme for viewing on a television set . Receivers can be external set-top boxes , or a built-in television tuner . Satellite television provides a wide range of channels and services . It is the only television available in many remote geographic areas without terrestrial television or cable television service . Modern systems signals are relayed from a communications satellite on the Ku band frequencies ( 12 -- 18 GHz ) requiring only a small dish less than a meter in diameter . The first satellite TV systems were an obsolete type now known as television receive-only . These systems received weaker analog signals transmitted in the C-band ( 4 -- 8 GHz ) from FSS type satellites , requiring the use of large 2-3 meter dishes . Consequently , these systems were nicknamed `` big dish '' systems , and were more expensive and less popular . Early systems used analog signals , but modern ones use digital signals which allow transmission of the modern television standard high-definition television . Different receivers are required for the two types . Some transmissions and channels are unencrypted and therefore free-to-air or free-to-view , while many other channels are transmitted with encryption ( pay television ) , requiring the customer to subscribe and pay a monthly fee to receive the programming .
578	Years_of_Living_Dangerously	'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.'	Years of Living Dangerously Years of Living Dangerously is an American documentary television series focusing on global warming . The first season , of nine weekly episodes , premiered in the US on April 13 , 2014 , on Showtime . It won an Emmy Award as Outstanding Documentary or Nonfiction Series . The second season , consisting of eight episodes , aired on the National Geographic Channel , beginning on October 30 , 2016 , with broader international distribution than the first season . Executive producers included James Cameron , Arnold Schwarzenegger , Robert Palumbo , and series creators Joel Bach and David Gelber ( formerly of 60 Minutes ) . Joseph Romm and Heidi Cullen were the chief science advisors . The weekly episodes featured celebrity hosts with a history of environmental activism and well-known journalists with a background in environmental reportage . These `` correspondents '' traveled the world and throughout the U.S. to interview experts and ordinary people affected by , and seeking solutions to , the effects of global warming . They acted as reporters and proxies for the audience , asking questions to find out people 's opinions and to discover the scientific evidence . The final episode of season one featured an interview of President Barack Obama . Executive producers for season one were Cameron , Schwarzenegger , clean energy investor and environmental activist Daniel Abbasi , Jerry Weintraub , Bach and Gelber . Episodes explored the effects of rising sea levels , historic droughts and flooding , water scarcity , ocean acidification , deforestation and the rapidly increasing extinction rate of species , but also focused on `` solutions that individuals , communities , companies and even governments can use to address worldwide climate change '' , including cheaper solar and wind energy , advancing battery technology and electric cars . Hosts included Cameron , Schwarzenegger , Harrison Ford , Ian Somerhalder , America Ferrera , David Letterman , Gisele Bündchen , Jack Black , Matt Damon , Jessica Alba , Sigourney Weaver , and various other actors and journalists . Schwarzenegger reflected on how the series tries to make the issue of climate change resonate with the public : `` I think the environmental movement only can be successful if we are simple and clear and make it a human story . We will tell human stories in this project . The scientists would never get the kind of attention that someone in show business gets . '' Cameron elaborated : `` We did n't use our celebrities as talking head experts , because they 're not climate experts . They were concerned , intelligent , curious citizens who were out to find answers . They were functioning as journalists . '' Newsweek said that the celebrity hosts `` lend sparks to an issue that sends most viewers for the exits '' .
819	Climate_change_and_ecosystems	Climate change need not endanger anyone"	Climate change and ecosystems This article is about climate change and ecosystems .
2038	Bushfires_in_Australia	Past Australian droughts occurred when global temperatures were lower than now and wetter years occurred when such temperatures were rising.	Bushfires in Australia Bushfires in Australia are frequent events during the warmer months of the year , due to Australia 's mostly hot , dry climate . Each year , such fires impact extensive areas . On one hand , they can cause property damage and loss of human life . On the other hand , certain native flora in Australia have evolved to rely on bushfires as a means of reproduction , and fire events are an interwoven and an essential part of the ecology of the continent . For thousands of years , Indigenous Australians have used fire to foster grasslands for hunting and to clear tracks through dense vegetation . Major firestorms that result in severe loss of life are often named based on the day on which they occur , such as Ash Wednesday and Black Saturday . Some of the most intense , extensive and deadly bushfires commonly occur during droughts and heat waves , such as the 2009 Southern Australia heat wave , which precipitated the conditions during the 2009 Black Saturday bushfires in which 173 people lost their lives . Other major conflagrations include the 1983 Ash Wednesday bushfires , the 2003 Eastern Victorian alpine bushfires and the 2006 December Bushfires . Global warming is increasing the frequency and severity of bushfires .
2583	Human_impact_on_the_environment	"Each unit of CO2 you put into the atmosphere has less and less of a warming impact.	Human impact on the environment Human impact on the environment or anthropogenic impact on the environment includes impacts on biophysical environments , biodiversity , and other resources . The term anthropogenic designates an effect or object resulting from human activity . The term was first used in the technical sense by Russian geologist Alexey Pavlov , and was first used in English by British ecologist Arthur Tansley in reference to human influences on climax plant communities . The atmospheric scientist Paul Crutzen introduced the term `` Anthropocene '' in the mid-1970s . The term is sometimes used in the context of pollution emissions that are produced as a result of human activities but applies broadly to all major human impacts on the environment .
701	Global_warming_controversy	"'Those eruptions happened relatively early in our study period, which pushed down temperatures in the first part of the dataset, which caused the overall record to show an exaggerated warming trend,' Christy said.	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 .
230	Antarctica	In the early 2000s, ice shelves began disintegrating in several parts of Antarctica, and scientists realized that process could greatly accelerate the demise of the vastly larger ice sheets themselves.	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 .
1525	Scientific_consensus_on_climate_change	Earth's changing climate is a critical issue and poses the risk of significant environmental, social and economic disruptions around the globe.	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.
3064	Post-glacial_rebound	No warming since at least 1995, no melting glaciers and now no rising sea levels.	Post-glacial rebound Post-glacial rebound ( also called either isostatic rebound or crustal rebound ) is the rise of land masses that were depressed by the huge weight of ice sheets during the last glacial period , through a process known as isostatic depression . Post-glacial rebound and isostatic depression are different parts of a process known as either glacial isostasy , glacial isostatic adjustment , or glacioisostasy . Glacioisostasy is the solid Earth deformation associated with changes in ice mass distribution . The most obvious and direct effects of post-glacial rebound are readily apparent in parts of Northern Eurasia , Northern America , Patagonia , and Antarctica . However , through processes known as ocean siphoning and continental levering , the effects of post-glacial rebound on sea level are felt globally far from the locations of current and former ice sheets .
1831	Air_pollution	(Koch Industries) is among the worst in toxic air pollution in the entire United States ... and churns out more climate-changing greenhouse gases than oil giants Chevron, Shell and Valero.	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 .
388	Planetary_habitability	We have also been told the problem is DEFINITELY NOT a billions-year-old planet running through cycles where the temperature might fluctuate a bit.	Planetary habitability Planetary habitability is the measure of a planet 's or a natural satellite 's potential to have habitable environments hospitable to life . Habitable environments do not need to contain life . Life may develop directly on a planet or satellite or be transferred to it from another body , a hypothetical process known as panspermia . As the existence of life beyond Earth is unknown , planetary habitability is largely an extrapolation of conditions on Earth and the characteristics of the Sun and Solar System which appear favorable to life 's flourishing -- in particular those factors that have sustained complex , multicellular organisms and not just simpler , unicellular creatures . Research and theory in this regard is a component of planetary science and the emerging discipline of astrobiology . An absolute requirement for life is an energy source , and the notion of planetary habitability implies that many other geophysical , geochemical , and astrophysical criteria must be met before an astronomical body can support life . In its astrobiology roadmap , NASA has defined the principal habitability criteria as `` extended regions of liquid water , conditions favorable for the assembly of complex organic molecules , and energy sources to sustain metabolism '' . In determining the habitability potential of a body , studies focus on its bulk composition , orbital properties , atmosphere , and potential chemical interactions . Stellar characteristics of importance include mass and luminosity , stable variability , and high metallicity . Rocky , wet terrestrial-type planets and moons with the potential for Earth-like chemistry are a primary focus of astrobiological research , although more speculative habitability theories occasionally examine alternative biochemistries and other types of astronomical bodies . The idea that planets beyond Earth might host life is an ancient one , though historically it was framed by philosophy as much as physical science.This article is an analysis of planetary habitability from the perspective of contemporary physical science . A historical viewpoint on the possibility of habitable planets can be found at Beliefs in extraterrestrial life and Cosmic pluralism . For a discussion of the probability of alien life see the Drake equation and Fermi paradox . Habitable planets are also a staple of fiction ; see Planets in science fiction . The late 20th century saw two breakthroughs in the field . The observation and robotic spacecraft exploration of other planets and moons within the Solar System has provided critical information on defining habitability criteria and allowed for substantial geophysical comparisons between the Earth and other bodies . The discovery of extrasolar planets , beginning in the early 1990s and accelerating thereafter , has provided further information for the study of possible extraterrestrial life . These findings confirm that the Sun is not unique among stars in hosting planets and expands the habitability research horizon beyond the Solar System . The chemistry of life may have begun shortly after the Big Bang , 13.8 billion years ago , during a habitable epoch when the Universe was only 10 -- 17 million years old . According to the panspermia hypothesis , microscopic life -- distributed by meteoroids , asteroids and other small Solar System bodies -- may exist throughout the Universe . Nonetheless , Earth is the only place in the Universe known to harbor life . Estimates of habitable zones around other stars , along with the discovery of hundreds of extrasolar planets and new insights into the extreme habitats here on Earth , suggest that there may be many more habitable places in the Universe than considered possible until very recently . On 4 November 2013 , astronomers reported , based on Kepler space mission data , that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of Sun-like stars and red dwarfs within the Milky Way . 11 billion of these estimated planets may be orbiting Sun-like stars . The nearest such planet may be 12 light-years away , according to the scientists .
1644	Retreat_of_glaciers_since_1850	Most glaciers are retreating, posing a serious problem for millions who rely on glaciers for water.	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 .
2834	Carbon_dioxide_in_Earth's_atmosphere	When stomata-derived CO2 (red) is compared to ice core-derived CO2 (blue), the stomata generally show much more variability in the atmospheric CO2 level and often show levels much higher than the ice cores.	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 .
418	Great_Barrier_Reef	describes a world of worsening food shortages and wildfires, and a mass die-off of coral reefs as soon as 2040	Great Barrier Reef The Great Barrier Reef is the world 's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over 2300 km over an area of approximately 344400 km2 . The reef is located in the Coral Sea , off the coast of Queensland , Australia . The Great Barrier Reef can be seen from outer space and is the world 's biggest single structure made by living organisms . This reef structure is composed of and built by billions of tiny organisms , known as coral polyps . It supports a wide diversity of life and was selected as a World Heritage Site in 1981 . CNN labelled it one of the seven natural wonders of the world . The Queensland National Trust named it a state icon of Queensland . A large part of the reef is protected by the Great Barrier Reef Marine Park , which helps to limit the impact of human use , such as fishing and tourism . Other environmental pressures on the reef and its ecosystem include runoff , climate change accompanied by mass coral bleaching , and cyclic population outbreaks of the crown-of-thorns starfish . According to a study published in October 2012 by the Proceedings of the National Academy of Sciences , the reef has lost more than half its coral cover since 1985 . The Great Barrier Reef has long been known to and used by the Aboriginal Australian and Torres Strait Islander peoples , and is an important part of local groups ' cultures and spirituality . The reef is a very popular destination for tourists , especially in the Whitsunday Islands and Cairns regions . Tourism is an important economic activity for the region , generating over AUD$ 3 billion per year . In November 2014 , Google launched Google Underwater Street View in 3D of the Great Barrier Reef . A March 2016 report stated that coral bleaching was more widespread than previously thought , seriously affecting the northern parts of the reef as a result of warming ocean temperatures . In October 2016 , Outside published an obituary for the reef ; the article was criticized for being premature and hindering efforts to bolster the resilience of the reef . In March 2017 , the journal Nature published a paper showing that huge sections of a 800-kilometre ( 500 mi ) stretch in the northern part of the reef had died in the course of 2016 due to high water temperatures , an event that the authors put down to the effects of global climate change .
2068	Global_warming	Global warming responsible for record 2019 July warmth in Alaska.	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 .
1202	Global_warming	The discrepancy between model-predicted warming and (lower) real-world observations has inspired new respect for natural climate variability relative to greenhouse-gas forcing.	Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned .
1098	Seawater	Marine life has nothing whatsoever to fear from ocean acidification."	Seawater Seawater , or salt water , is water from a sea or ocean . On average , seawater in the world 's oceans has a salinity of about 3.5 % ( 35 g/L , or 0.600 M ) This means that every kilogram ( roughly one litre by volume ) of seawater has approximately 35 g of dissolved salts ( predominantly sodium and chloride ions ) . Average density at the surface is 1.025 kg/L . Seawater is denser than both fresh water and pure water ( density 1.0 kg/L at 4 C ) because the dissolved salts increase the mass by a larger proportion than the volume . The freezing point of seawater decreases as salt concentration increases . At typical salinity , it freezes at about -2 C . The coldest seawater ever recorded ( in a liquid state ) was in 2010 , in a stream under an Antarctic glacier , and measured -2.6 C. Seawater pH is typically limited to a range between 7.5 and 8.4 . However , there is no universally accepted reference pH-scale for seawater and the difference between measurements based on different reference scales may be up to 0.14 units .
1156	Market_failure	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.	Market failure In economics , market failure is a situation in which the allocation of goods and services is not efficient . That is , there exists another conceivable outcome where an individual may be made better-off without making someone else worse-off . Market failures can be viewed as scenarios where individuals ' pursuit of pure self-interest leads to results that are not efficient -- that can be improved upon from the societal point of view . The first known use of the term by economists was in 1958 , but the concept has been traced back to the Victorian philosopher Henry Sidgwick . Market failures are often associated with time-inconsistent preferences , information asymmetries , non-competitive markets , principal -- agent problems , externalities , or public goods , thus existence of a market failure is often the reason that self-regulatory organizations , governments or supra-national institutions intervene in a particular market . Economists , especially microeconomists , are often concerned with the causes of market failure and possible means of correction . Such analysis plays an important role in many types of public policy decisions and studies . However , government policy interventions , such as taxes , subsidies , bailouts , wage and price controls , and regulations ( including poorly implemented attempts to correct market failure ) , may also lead to an inefficient allocation of resources , sometimes called government failure . Given the tension between , on the one hand , the undeniable costs to society caused by market failure , and on the other hand , the potential that attempts to mitigate these costs could lead to even greater costs from `` government failure '' , there is sometimes a choice between imperfect outcomes , i.e. imperfect market outcomes with or without government interventions . But either way , if a market failure exists the outcome is not Pareto efficient . Most mainstream economists believe that there are circumstances ( like building codes or endangered species ) in which it is possible for government or other organizations to improve the inefficient market outcome . Several heterodox schools of thought disagree with this as a matter of principle . An ecological market failure exists when human activity in a market economy is exhausting critical non-renewable resources , disrupting fragile ecosystems services , or overloading biospheric waste absorption capacities . In none of these cases does the criterion of Pareto efficiency obtain .
2455	Global_warming	When CO2 levels were higher in the past, solar levels were also lower.	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 .
181	Gas_exchange	Reefs need carbon dioxide; it's their basic food.	Gas exchange Gas exchange is the biological process by which gases move passively by diffusion across a surface . Typically , this surface is - or contains - a biological membrane that forms the boundary between an organism and its extracellular environment . Gases are constantly consumed and produced by cellular and metabolic reactions in most living things , so an efficient system for their exchange is required . Smaller organisms , such as bacteria , have a high surface-area to volume ratio . In these unicellular organisms , the external boundary of the organism - typically the cell membrane - is usually sufficient for the necessary gas exchange . Some small multicellular organisms , such as flatworms , are also able to perform sufficient gas exchange across the skin or cuticle that surrounds their bodies . However , in most larger organisms , which have a small surface-area to volume ratio , specialised structures with convoluted surfaces such as gills , pulmonary alveoli and spongy mesophyll provide the additional area needed for effective gas exchange . These convoluted surfaces may sometimes be internalised into the body of the organism : this is the case for alveoli , which form the inner surface of the mammalian lung ; spongy mesophyll , which is found inside the leaves of some kinds of plant ; and the gills of those molluscs that have them , which may be found in the mantle cavity . In aerobic organisms , gas exchange is particularly important for respiration , which involves the uptake of oxygen and release of carbon dioxide . Conversely , in oxygenic photosynthetic organisms such as most land plants , uptake of carbon dioxide and release of both oxygen and water vapour are the main gas-exchange processes occurring during the day . Other gas-exchange processes are important in less familiar organisms : e.g. carbon dioxide , methane and hydrogen are exchanged across the cell membrane of methanogenic archaea ; nitrogen is exchanged in denitrifying and nitrogen fixing bacteria ; and hydrogen sulfide and other gases are exchanged in giant tube worms .
1819	Hockey_stick_controversy	In particular, satellite data demonstrate for the last 17 years, there's been zero warming.	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 .
2963	Greenhouse_gas	When CO2 emissions are compared directly to CO2 levels, there is a strong correlation in the long term trends.	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 .
2536	Scientific_consensus_on_climate_change	But the central message of the IPCC AR4, is confirmed by the peer reviewed literature.	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.
2206	Global_warming	No climate model has predicted a cooling of the Earth – quite the contrary.	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 .
258	Global_warming	But the period has caused a headache for climate scientists because clearly there was no upswell in carbon dioxide that could account for such swift 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 .
2587	Carbon_dioxide	If the CO2 effect was saturated, adding more CO2 should add no additional greenhouse effect.	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 .
1121	Scientific_consensus_on_climate_change	Another consequence of the fast melting Arctic raises the possibility that there may be even worse extreme weather to come, according to a few scientists: titanic Atlantic superstorms and hurricanes barreling across Europe.	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.
1324	Deep_hypothermic_circulatory_arrest	cold deaths actually occur during moderate temperatures	Deep hypothermic circulatory arrest Deep hypothermic circulatory arrest ( DHCA ) is a surgical technique that involves cooling the body to temperatures below 20 ° C ( 68 ° F ) , and stopping blood circulation and brain function for up to one hour . It is used when blood circulation to the brain must be stopped because of delicate surgery within the brain , or because of surgery on large blood vessels that lead to or from the brain . DHCA is a form of carefully managed clinical death in which heartbeat and all brain activity cease . At normal body temperature of 37 ° C only several minutes of stopped blood circulation causes changes within the brain leading to permanent damage after circulation is restored . Reducing body temperature extends the time interval that such stoppage can be survived . At a brain temperature of 14 ° C , blood circulation can be safely stopped for 30 to 40 minutes . There is an increased incidence of brain injury at times longer than 40 minutes , but sometimes circulatory arrest for up to 60 minutes is used if life-saving surgery requires it . Infants tolerate longer periods of DHCA than adults . Applications of DHCA include repairs of the aortic arch , repairs to head and neck great vessels , repair of large cerebral aneurysms , repair of cerebral arteriovenous malformations , pulmonary thromboendarterectomy , and resection of tumors that have invaded the vena cava .
1910	Spirit_(rover)	It takes as much energy to make a solar panel as it likely generates in its entire life.	Spirit (rover) Spirit , also known as MER-A ( Mars Exploration Rover -- A ) or MER-2 , is a robotic rover on Mars , active from 2004 to 2010 . It was one of two rovers of NASA 's ongoing Mars Exploration Rover Mission . It landed successfully on Mars at 04:35 Ground UTC on January 4 , 2004 , three weeks before its twin , Opportunity ( MER-B ) , landed on the other side of the planet . Its name was chosen through a NASA-sponsored student essay competition . The rover became stuck in late 2009 , and its last communication with Earth was sent on March 22 , 2010 . The rover completed its planned 90-sol mission . Aided by cleaning events that resulted in more energy from its solar panels , Spirit went on to function effectively over twenty times longer than NASA planners expected . Spirit also logged 7.73 km of driving instead of the planned 600 m , allowing more extensive geological analysis of Martian rocks and planetary surface features . Initial scientific results from the first phase of the mission ( the 90-sol prime mission ) were published in a special issue of the journal Science . On May 1 , 2009 ( 5 years , 3 months , 27 Earth days after landing ; 21.6 times the planned mission duration ) , Spirit became stuck in soft soil . This was not the first of the mission 's `` embedding events '' and for the following eight months NASA carefully analyzed the situation , running Earth-based theoretical and practical simulations , and finally programming the rover to make extrication drives in an attempt to free itself . These efforts continued until January 26 , 2010 when NASA officials announced that the rover was likely irrecoverably obstructed by its location in soft soil , though it continued to perform scientific research from its current location . The rover continued in a stationary science platform role until communication with Spirit stopped on sol 2210 ( March 22 , 2010 ) . JPL continued to attempt to regain contact until May 24 , 2011 , when NASA announced that efforts to communicate with the unresponsive rover had ended , calling the mission complete . A formal farewell took place at NASA headquarters after the 2011 Memorial Day holiday and was televised on NASA TV . The Jet Propulsion Laboratory ( JPL ) , a division of the California Institute of Technology in Pasadena , manages the Mars Exploration Rover project for NASA 's Office of Space Science , Washington .
420	International_Energy_Agency	International Energy Agency, a global analysis organization, "continue to see a role for coal for the foreseeable future."	International Energy Agency The International Energy Agency ( IEA ) ( Agence internationale de l'énergie ) is a Paris-based autonomous intergovernmental organization established in the framework of the Organisation for Economic Co-operation and Development ( OECD ) in 1974 in the wake of the 1973 oil crisis . The IEA was initially dedicated to responding to physical disruptions in the supply of oil , as well as serving as an information source on statistics about the international oil market and other energy sectors . The IEA acts as a policy adviser to its member states , but also works with non-member countries , especially China , India , and Russia . The Agency 's mandate has broadened to focus on the `` 3Es '' of effectual energy policy : energy security , economic development , and environmental protection . The latter has focused on mitigating climate change . The IEA has a broad role in promoting alternate energy sources ( including renewable energy ) , rational energy policies , and multinational energy technology co-operation . IEA member countries are required to maintain total oil stock levels equivalent to at least 90 days of the previous year 's net imports . At the end of July 2009 , IEA member countries held a combined stockpile of almost 4.3 billion barrels ( 680,000,000 m3 ) of oil . On 1 September 2015 , Fatih Birol took office as the new Executive Director , succeeding in this position former Dutch Minister of Economic Affairs , Maria van der Hoeven .
1603	Coral_reef	Coral atolls grow as sea levels rise.	Coral reef Coral reefs are diverse underwater ecosystems held together by calcium carbonate structures secreted by corals . Coral reefs are built by colonies of tiny animals found in marine waters that contain few nutrients . Most coral reefs are built from stony corals , which in turn consist of polyps that cluster in groups . The polyps belong to a group of animals known as Cnidaria , which also includes sea anemones and jellyfish . Unlike sea anemones , corals secrete hard carbonate exoskeletons which support and protect the coral polyps . Most reefs grow best in warm , shallow , clear , sunny and agitated waters . Often called `` rainforests of the sea '' , shallow coral reefs form some of the most diverse ecosystems on Earth . They occupy less than 0.1 % of the world 's ocean surface , about half the area of France , yet they provide a home for at least 25 % of all marine species , including fish , mollusks , worms , crustaceans , echinoderms , sponges , tunicates and other cnidarians . Paradoxically , coral reefs flourish even though they are surrounded by ocean waters that provide few nutrients . They are most commonly found at shallow depths in tropical waters , but deep water and cold water corals also exist on smaller scales in other areas . Coral reefs deliver ecosystem services to tourism , fisheries and shoreline protection . The annual global economic value of coral reefs is estimated between US$ 29.8-375 billion . However , coral reefs are fragile ecosystems , partly because they are very sensitive to water temperature . They are under threat from climate change , oceanic acidification , blast fishing , cyanide fishing for aquarium fish , sunscreen use , overuse of reef resources , and harmful land-use practices , including urban and agricultural runoff and water pollution , which can harm reefs by encouraging excess algal growth .
2032	Coronal_cloud	The lack of any sunspots suggests the current solar minimum is one of the 'deepest' in 100 years.	Coronal cloud A coronal cloud is the cloud of hot plasma gas surrounding a coronal mass ejection . It is usually made up of protons and electrons . When a coronal mass ejection occurs , it is the coronal cloud that usually reaches Earth and causes damage to electrical equipment and space satellites , not the ejection or flare itself . The damage is mostly the result of the high amount of electricity moving through the atmosphere . A coronal cloud is released when a solar flare becomes a coronal mass ejection ; the coronal cloud often contains more radioactive particles than the mass ejection itself . A coronal mass ejection occurs when a solar flare becomes so hot that it snaps and breaks in two , becoming a `` rope '' of heat and magnetism that stretches between two sunspots . The resulting coronal mass ejection can be compared to a horseshoe magnet , the sunspots being the poles and the oscillating magnetic connector the handle . Coronal mass ejections typically do not last very long , because they cool down as the coronal cloud of gas is released and begins to hurtle away from the sun .
1240	Arctic_Circle	"Ice-free means the central basin of the Arctic will be ice-free	Arctic Circle The Arctic Circle is the most northerly of the abstract five major circles of latitude as shown on maps of the Earth . It marks the northernmost point at which the noon sun is just visible on the northern winter solstice and the southernmost point at which the midnight sun is just visible on the northern summer solstice . The region north of this circle is known as the Arctic , and the zone just to the south is called the Northern Temperate Zone . North of the Arctic Circle , the sun is above the horizon for twenty-four continuous hours at least once per year ( and therefore visible at midnight ) and below the horizon for twenty-four continuous hours at least once per year ( and therefore not visible at noon ) ; this is also true within the equivalent polar circle in the Southern Hemisphere , the Antarctic Circle . The position of the Arctic Circle is not fixed ; as of , it runs north of the Equator . Its latitude depends on the Earth 's axial tilt , which fluctuates within a margin of 2 ° over a 40,000-year period , due to tidal forces resulting from the orbit of the Moon . Consequently , the Arctic Circle is currently drifting northwards at a speed of about 15 m per year .
2009	Arthur_D._Levinson	Top Scientist Hal Lewis Resigns Over Climate Change Corruption	Arthur D. Levinson Arthur D. Levinson ( born March 31 , 1950 ) is an American businessman and is the current CEO of Calico ( an Alphabet Inc. venture ) and chairman of Apple Inc. ( 2011 to present ) . He is the former chief executive officer ( 1995 to 2009 ) and chairman ( 1999 to 2014 ) of Genentech . In addition to serving on the board of Apple Inc. ( 2000 -- present ) , Levinson serves on the board of directors of the Broad Institute ( affiliated with MIT and Harvard ) . Previously , Levinson had served on the board of directors at F. Hoffmann-La Roche ( 2010-2014 ) , NGM Biopharmaceuticals ( 2009-2014 ) , and Amyris Biotechnologies ( 2009-2014 ) . He currently serves on the Board of Scientific Consultants of the Memorial Sloan Kettering Cancer Center , the Industrial Advisory Board of the California Institute for Quantitative Biosciences ( QB3 ) , the Advisory Council for the Princeton University Department of Molecular Biology and the Advisory Council for the Lewis-Sigler Institute for Integrative Genomics .
565	Scientific_method	In looking at Earth's past, scientists can predict what the future will look like	Scientific method The scientific method is a body of techniques for investigating phenomena , acquiring new knowledge , or correcting and integrating previous knowledge . To be termed scientific , a method of inquiry is commonly based on empirical or measurable evidence subject to specific principles of reasoning . The Oxford Dictionaries Online define the scientific method as `` a method or procedure that has characterized natural science since the 17th century , consisting in systematic observation , measurement , and experiment , and the formulation , testing , and modification of hypotheses '' . Experiments need to be designed to test hypotheses . The most important part of the scientific method is the experiment . The scientific method is a continuous process , which usually begins with observations about the natural world . Human beings are naturally inquisitive , so they often come up with questions about things they see or hear and often develop ideas ( hypotheses ) about why things are the way they are . The best hypotheses lead to predictions that can be tested in various ways , including making further observations about nature . In general , the strongest tests of hypotheses come from carefully controlled and replicated experiments that gather empirical data . Depending on how well the tests match the predictions , the original hypothesis may require refinement , alteration , expansion or even rejection . If a particular hypothesis becomes very well supported a general theory may be developed . Although procedures vary from one field of inquiry to another , identifiable features are frequently shared in common between them . The overall process of the scientific method involves making conjectures ( hypotheses ) , deriving predictions from them as logical consequences , and then carrying out experiments based on those predictions . A hypothesis is a conjecture , based on knowledge obtained while formulating the question . The hypothesis might be very specific or it might be broad . Scientists then test hypotheses by conducting experiments . Under modern interpretations , a scientific hypothesis must be falsifiable , implying that it is possible to identify a possible outcome of an experiment that conflicts with predictions deduced from the hypothesis ; otherwise , the hypothesis can not be meaningfully tested . The purpose of an experiment is to determine whether observations agree with or conflict with the predictions derived from a hypothesis . Experiments can take place anywhere from a college lab to CERN 's Large Hadron Collider . There are difficulties in a formulaic statement of method , however . Though the scientific method is often presented as a fixed sequence of steps , it represents rather a set of general principles . Not all steps take place in every scientific inquiry ( or to the same degree ) , and are not always in the same order . Some philosophers and scientists have argued that there is no scientific method , such as Lee Smolin and Paul Feyerabend ( in his Against Method ) . Nola and Sankey remark that `` For some , the whole idea of a theory of scientific method is yester-year 's debate '' .
1684	Second_law_of_thermodynamics	The 2nd law of thermodynamics is consistent with the greenhouse effect which is directly observed.	Second law of thermodynamics The second law of thermodynamics states that the total entropy of an isolated system can only increase over time . It can remain constant in ideal cases where the system is in a steady state ( equilibrium ) or undergoing a reversible process . The increase in entropy accounts for the irreversibility of natural processes , and the asymmetry between future and past . Historically , the second law was an empirical finding that was accepted as an axiom of thermodynamic theory . Statistical thermodynamics , classical or quantum , explains the microscopic origin of the law . The second law has been expressed in many ways . Its first formulation is credited to the French scientist Sadi Carnot in 1824 , who showed that there is an upper limit to the efficiency of conversion of heat to work in a heat engine .
1506	Mediterranean_Sea	Most likely the primary control knob on climate change is the ocean waters and this environment that we live in.	Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean , surrounded by the Mediterranean Basin and almost completely enclosed by land : on the north by Southern Europe and Anatolia , on the south by North Africa , and on the east by the Levant . The sea is sometimes considered a part of the Atlantic Ocean , although it is usually identified as a separate body of water . The name Mediterranean is derived from the Latin mediterraneus , meaning `` inland '' or `` in the middle of land '' ( from medius , `` middle '' and terra , `` land '' ) . It covers an approximate area of 2.5 million km2 ( 965,000 sq mi ) , but its connection to the Atlantic ( the Strait of Gibraltar ) is only 14 km wide . The Strait of Gibraltar is a narrow strait that connects the Atlantic Ocean to the Mediterranean Sea and separates Gibraltar and Spain in Europe from Morocco in Africa . In oceanography , it is sometimes called the Eurafrican Mediterranean Sea or the European Mediterranean Sea to distinguish it from mediterranean seas elsewhere . The Mediterranean Sea has an average depth of 1500 m and the deepest recorded point is 5267 m in the Calypso Deep in the Ionian Sea . The sea is bordered on the north by Europe , the east by Asia , and in the south by Africa . It is located between latitudes 30 ° and 46 ° N and longitudes 6 ° W and 36 ° E. Its west-east length , from the Strait of Gibraltar to the Gulf of Iskenderun , on the southwestern coast of Turkey , is approximately 4,000 km ( 2,500 miles ) . The sea 's average north-south length , from Croatia 's southern shore to Libya , is approximately 800 km ( 500 miles ) . The Mediterranean Sea , including the Sea of Marmara ( connected by the Dardanelles to the Aegean Sea ) , has a surface area of approximately 2,510,000 square km ( 970,000 square miles ) . The sea was an important route for merchants and travelers of ancient times that allowed for trade and cultural exchange between emergent peoples of the region . The history of the Mediterranean region is crucial to understanding the origins and development of many modern societies . The countries with coastlines on the Mediterranean Sea are Albania , Algeria , Bosnia and Herzegovina , Croatia , Cyprus , Egypt , France , Greece , Israel , Italy , Lebanon , Libya , Malta , Morocco , Monaco , Montenegro , Slovenia , Spain , Syria , Tunisia and Turkey . In addition , the Gaza Strip and the British Overseas Territories of Gibraltar and Akrotiri and Dhekelia have coastlines on the sea .
3105	Scientific_consensus_on_climate_change	Global warming theory holds that one of the fingerprints of human-induced global warming is more rapid warming in the lower troposphere than at the surface (James Taylor)	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.
207	2012_in_science	Each of the six major past ice ages began when the atmospheric carbon dioxide content was far higher than at present.	2012 in science The year 2012 involved many significant scientific events and discoveries , including the first orbital rendezvous by a commercial spacecraft , the discovery of a particle highly similar to the long-sought Higgs boson , and the near-eradication of guinea worm disease . A total of 72 successful orbital spaceflights occurred in 2012 , and the year also saw numerous developments in fields such as robotics , 3D printing , stem cell research and genetics . Over 540,000 technological patent applications were made in the United States alone in 2012 . 2012 was declared the International Year of Sustainable Energy for All by the United Nations . 2012 also marked Alan Turing Year , a celebration of the life and work of the English mathematician , logician , cryptanalyst and computer scientist Alan Turing .
559	Effects_of_climate_change_on_plant_biodiversity	And there is a lot of evidence that climate change is diminishing biodiversity, which can be seen in these alpine meadows as well.	Effects of climate change on plant biodiversity Environmental conditions play a key role in defining the function and distribution of plants , in combination with other factors . Changes in long term environmental conditions that can be collectively coined climate change are known to have had enormous impacts on current plant diversity patterns ; further impacts are expected in the future . It is predicted that climate change will remain one of the major drivers of biodiversity patterns in the future .
649	Farleigh_Hungerford_Castle	"Houlton has been exploring this possibility for years.	Farleigh Hungerford Castle Farleigh Hungerford Castle , sometimes called Farleigh Castle or Farley Castle , is a medieval castle in Farleigh Hungerford , Somerset , England . The castle was built in two phases : the inner court was constructed between 1377 and 1383 by Sir Thomas Hungerford , who made his fortune working as a steward to John of Gaunt . The castle was built to a quadrangular design , already slightly old-fashioned , on the site of an existing manor house overlooking the River Frome . A park was attached to the castle , requiring the destruction of a local village . His son , Sir Walter Hungerford , a successful knight and courtier to Henry V , became rich during the Hundred Years War with France and extended the castle with an additional , outer court , enclosing the parish church in the process . By Walter 's death in 1449 , the substantial castle was richly appointed and its chapel decorated with murals . The castle largely remained in the hands of the Hungerford family over the next two centuries , despite periods during the War of the Roses in which it was held by the Crown following the attainder and execution of members of the family . At the outbreak of the English Civil War in 1642 , the castle , modernized to the latest Tudor and Stuart fashions , was held by Sir Edward Hungerford . Edward declared his support for Parliament , becoming a leader of the Roundheads in Wiltshire . Farleigh Hungerford was seized by Royalist forces in 1643 , but recaptured by Parliament without a fight near the end of the conflict in 1645 . As a result , it escaped slighting following the war , unlike many other castles in the south-west of England . The last member of the Hungerford family to hold the castle , Sir Edward Hungerford , inherited it in 1657 , but his gambling and expensive living forced him to sell the property in 1686 . By the 18th century the castle was no longer lived in by its owners and fell into disrepair ; in 1730 it was bought by the Houlton family , when much of it was broken up for salvage . Antiquarian and tourist interest in the now ruined castle increased through the 18th and 19th centuries . The castle chapel was repaired in 1779 and became a museum of curiosities , complete with the murals rediscovered on its walls in 1844 and a number of rare lead anthropomorphic coffins from the mid-17th century . In the 1915 Farleigh Hungerford Castle was sold to the Office of Works and a controversial restoration programme began . It is now owned by English Heritage , who operate it as a tourist attraction , and the castle is a Grade I listed building and a Scheduled Ancient Monument .
2821	Climate_change_(general_concept)	The fact that so many studies on climate change don't bother to endorse the consensus position is significant because scientists have largely moved from what's causing global warming onto discussing details of the problem (eg - how fast, how soon, impacts, etc).	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.
2199	Climate_change_mitigation	The consequences of climate change become increasingly bad after each additional degree of warming, with the consequences of 2°C being quite damaging and the consequences of 4°C being potentially catastrophic.	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 .
2222	Quaternary_extinction_event	A large number of ancient mass extinction events have been strongly linked to global climate change.	Quaternary extinction event The Quaternary period saw the extinctions of numerous predominantly larger , especially megafaunal , species , many of which occurred during the transition from the Pleistocene to the Holocene epoch . However , this extinction wave did not stop at the end of the Pleistocene , but continued , especially on isolated islands , in human-caused extinctions , although there is debate as to whether these should be considered separate events or part of the same event . Among the main causes hypothesized by paleontologists are natural climate change and overkill by humans , who appeared during the Middle Pleistocene and migrated to many regions of the world during the Late Pleistocene and Holocene . A variant of the latter possibility is the second-order predation hypothesis , which focuses more on the indirect damage caused by overcompetition with nonhuman predators . The spread of disease is also discussed as a possible reason .
42	Global_warming	Unprecedented climate change has caused sea level at Sydney Harbour to rise approximately 0.0 cm over the past 140 years.	Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned .
1339	Skepticism	"Dr Browman, a marine scientist for 35 years, said he was not saying that ocean acidification posed no threat, but that he believed that "a higher level of academic scepticism" should be applied to the topic.	Skepticism Skepticism ( American English ) or scepticism ( British English ; see spelling differences ) is generally any questioning attitude or doubt towards one or more items of putative knowledge or belief . It is often directed at domains , such as morality ( moral skepticism ) , religion ( skepticism about the existence of God ) , or knowledge ( skepticism about the possibility of knowledge , or of certainty ) . Formally , skepticism as a topic occurs in the context of philosophy , particularly epistemology , although it can be applied to any topic such as politics , religion , and pseudoscience . Philosophical skepticism comes in various forms . Radical forms of skepticism deny that knowledge or rational belief is possible and urge us to suspend judgment on many or all controversial matters . More moderate forms of skepticism claim only that nothing can be known with certainty , or that we can know little or nothing about the `` big questions '' in life , such as whether God exists or whether there is an afterlife . Religious skepticism is `` doubt concerning basic religious principles ( such as immortality , providence , and revelation ) '' . Scientific skepticism concerns testing beliefs for reliability , by subjecting them to systematic investigation using the scientific method , to discover empirical evidence for them .
1575	Arctic	Arctic sea ice loss is matched by Antarctic sea ice gain.	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 .
2560	Sea_level	In the 11,400 years since the end of the last Ice Age, sea level has risen at an average of 4 feet/century, though it is now rising much more slowly because very nearly all of the land-based ice that is at low enough latitudes and altitudes to melt has long since gone."	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 ) .
2939	Ice_age	"The climate of this planet oscillates between periods of approximately 30 years of warming followed by approximately 30 years of cooling.	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 .
1013	Sea_level_rise	Global sea level rise surged between November 2014 and February 2016, with the El Niño event helping the oceans rise by 15mm.	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 .
737	Proxy_(climate)	The new research showed that [oxygen isotopes in foraminifera] can change	Proxy (climate) In the study of past climates ( `` paleoclimatology '' ) , climate proxies are preserved physical characteristics of the past that stand in for direct meteorological measurements and enable scientists to reconstruct the climatic conditions over a longer fraction of the Earth 's history . Reliable global records of climate only began in the 1880s , and proxies provide the only means for scientists to determine climatic patterns before record-keeping began . Examples of proxies include ice cores , tree rings , sub-fossil pollen , boreholes , corals , lake and ocean sediments , and carbonate speleothems . The character of deposition or rate of growth of the proxies ' material has been influenced by the climatic conditions of the time in which they were laid down or grew . Chemical traces produced by climatic changes , such as quantities of particular isotopes , can be recovered from proxies . Some proxies , such as gas bubbles trapped in ice , enable traces of the ancient atmosphere to be recovered and measured directly to provide a history of fluctuations in the composition of the Earth 's atmosphere . To produce the most precise results , systematic cross-verification between proxy indicators is necessary for accuracy in readings and record-keeping . Proxies can be combined to produce temperature reconstructions longer than the instrumental temperature record and can inform discussions of global warming . The distribution of proxy records , just like the instrumental record , is not at all uniform , with more records in the northern hemisphere .
742	Agriculture	Global human emissions are only 3 per cent of total annual emissions.	Agriculture Agriculture or farming is the cultivation and breeding of animals , plants and fungi for food , fiber , biofuel , medicinal plants and other products used to sustain and enhance human life . Agriculture was the key development in the rise of sedentary human civilization , whereby farming of domesticated species created food surpluses that nurtured the development of civilization . The study of agriculture is known as agricultural science . The history of agriculture dates back thousands of years , and its development has been driven and defined by greatly different climates , cultures , and technologies . Industrial agriculture based on large-scale monoculture farming has become the dominant agricultural methodology . Modern agronomy , plant breeding , agrochemicals such as pesticides and fertilizers , and technological developments have in many cases sharply increased yields from cultivation , but at the same time have caused widespread ecological damage and negative human health effects . Selective breeding and modern practices in animal husbandry have similarly increased the output of meat , but have raised concerns about animal welfare and the health effects of the antibiotics , growth hormones , and other chemicals commonly used in industrial meat production . Genetically modified organisms are an increasing component of agriculture , although they are banned in several countries . Agricultural food production and water management are increasingly becoming global issues that are fostering debate on a number of fronts . Significant degradation of land and water resources , including the depletion of aquifers , has been observed in recent decades , and the effects of global warming on agriculture and of agriculture on global warming are still not fully understood . The major agricultural products can be broadly grouped into foods , fibers , fuels , and raw materials . Specific foods include cereals ( grains ) , vegetables , fruits , oils , meats and spices . Fibers include cotton , wool , hemp , silk and flax . Raw materials include lumber and bamboo . Other useful materials are also produced by plants , such as resins , dyes , drugs , perfumes , biofuels and ornamental products such as cut flowers and nursery plants . Over one third of the world 's workers are employed in agriculture , second only to the service sector , although the percentages of agricultural workers in developed countries has decreased significantly over the past several centuries .
3059	IPCC_Fourth_Assessment_Report	Models and direct observations find that CFCs only contribute a fraction of the warming supplied by other greenhouse gases.	IPCC Fourth Assessment Report Climate Change 2007 , the Fourth Assessment Report ( AR4 ) of the United Nations Intergovernmental Panel on Climate Change ( IPCC ) , is the fourth in a series of reports intended to assess scientific , technical and socio-economic information concerning climate change , its potential effects , and options for adaptation and mitigation . The report is the largest and most detailed summary of the climate change situation ever undertaken , produced by thousands of authors , editors , and reviewers from dozens of countries , citing over 6,000 peer-reviewed scientific studies . It supersedes the Third Assessment Report ( 2001 ) , and is superseded by the Fifth Assessment Report . The headline findings of the report were : `` warming of the climate system is unequivocal '' , and `` most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations . ''
434	Global_warming	It's also a sufficiently long period to include several cycles of climate variability.	Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned .
2880	Concentrated_solar_power	For example, geothermal energy is available at all times, concentrated solar thermal energy has storage capability, and wind energy can be stored in compressed air.	Concentrated solar power Concentrated solar power ( also called concentrating solar power , concentrated solar thermal , and CSP ) systems generate solar power by using mirrors or lenses to concentrate a large area of sunlight , or solar thermal energy , onto a small area . Electricity is generated when the concentrated light is converted to heat , which drives a heat engine ( usually a steam turbine ) connected to an electrical power generator or powers a thermochemical reaction ( experimental ) . Heat storage in molten salts allows some solar thermal plants to continue to generate after sunset and adds value to such systems when compared to photovoltaic panels . CSP is being commercialized and the CSP market saw about 740 megawatt ( MW ) of generating capacity added between 2007 and the end of 2010 . More than half of this ( about 478 MW ) was installed during 2010 , bringing the global total to 1095 MW . Spain added 400 MW in 2010 , taking the global lead with a total of 632 MW , while the US ended the year with 509 MW after adding 78 MW , including two fossil -- CSP hybrid plants . The Middle East is also ramping up their plans to install CSP based projects . Shams-I has been installed in Abu Dhabi , by Masdar . The largest CSP projects in the world is Ivanpah Solar Power Facility in the United States ( which uses solar power tower technology ) and Mojave Solar Project ( which uses parabolic troughs ) . As of January 2014 , Spain had a total capacity of 2,300 MW making this country the world leader in CSP . United States follows with 1,740 MW . Interest is also notable in North Africa and the Middle East , as well as India and China . In Italy , a handful of companies are trying to get authorization for 14 plants , totalling 392 MW , despite a strong local and political opposition . The global market has been dominated by parabolic-trough plants , which account for 90 % of CSP plants . In most cases , CSP technologies currently can not compete on price with photovoltaics ( solar panels ) , which have experienced huge growth in recent years due to falling prices of the panels and much smaller operating costs . However , the Chile Copiapó reached cents 6.3 / kWh . In 2015 , CSP represented less than 2 % of worldwide installed capacity of solar electricity plants . CSP is not to be confused with concentrator photovoltaics ( CPV ) . In CPV , the concentrated sunlight is converted directly to electricity via the photovoltaic effect .
1049	Milwaukee	So far this month, there have been nearly 5,000 daily record highs set or tied, compared to just 42 daily record lows.	Milwaukee Milwaukee ( -LSB- mᵻlˈwɔːki -RSB- , -LSB- localˈmwɔːki -RSB- ) is the largest city in the state of Wisconsin and the fifth-largest city in the Midwestern United States . The county seat of Milwaukee County , it is on Lake Michigan 's western shore . Ranked by estimated 2014 population , Milwaukee was the 31st largest city in the United States . The city 's estimated population in 2015 was 600,155 . Milwaukee is the main cultural and economic center of the Milwaukee metropolitan area . It is also part of the larger Milwaukee-Racine-Waukesha , WI combined statistical area , which had an estimated population of 2,026,243 in the 2010 census . The first Europeans to pass through the area were French Catholic missionaries and fur traders . In 1818 , the French Canadian explorer Solomon Juneau settled in the area , and in 1846 Juneau 's town combined with two neighboring towns to incorporate as the city of Milwaukee . Large numbers of German immigrants helped increase the city 's population during the 1840s , with Poles and other immigrants arriving in the following decades . Milwaukee is known for its brewing traditions . The city is experiencing its largest construction boom since the 1960s . Major new additions to the city in the past two decades include the Milwaukee Riverwalk , the Wisconsin Center , Miller Park , an expansion to the Milwaukee Art Museum , Milwaukee Repertory Theater , and Pier Wisconsin , as well as major renovations to the UW -- Milwaukee Panther Arena . The under-construction Wisconsin Entertainment and Sports Center is scheduled to open in 2018 .
261	Hockey_stick_controversy	in 1995 one scientist at the IPCC – Jonathan Overpeck – wrote an email to a colleague claiming 'we have to get rid of the Medieval Warm Period.'	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 .
1690	Greenhouse_gas	That human CO2 is causing global warming is known with high certainty & confirmed by observations.	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 .
2086	Extreme_weather	Extreme weather isn't caused by global warming	Extreme weather Extreme weather includes unexpectable , unusual , unpredictable severe or unseasonal weather ; weather at the extremes of the historical distribution -- the range that has been seen in the past . Often , extreme events are based on a location 's recorded weather history and defined as lying in the most unusual ten percent . In recent years some extreme weather events have been attributed to human-induced global warming , with studies indicating an increasing threat from extreme weather in the future .
811	Effects_of_global_warming	But [climate scientists] say that aspects of the case of Hurricane Harvey—and the recent history of tropical cyclones worldwide—suggest global warming is making a bad situation worse.	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 .
1577	Art_Robinson	Over 31,000 scientists signed the OISM Petition Project.	Art Robinson Arthur Brouhard Robinson (born March 24, 1942) is an American biochemist, conservative activist, and politician. He was the five-time Republican nominee for the United States House of Representatives for Oregon's 4th congressional district. In 2020 he became Senator-elect of Oregons 2nd Senate District. A former faculty member of the University of California, San Diego, Robinson now runs a privately funded laboratory known as the Oregon Institute of Science and Medicine in Cave Junction, Oregon, a newsletter called Access to Energy, and publishes the Robinson Self-Teaching Home School Curriculum.As the Republican nominee for the Fourth District in Oregon, Robinson ran and lost to Democratic incumbent Peter DeFazio in five consecutive elections: 2010, 2012, 2014, 2016, and 2018. He served as Chairman of the Oregon Republican Party from August 2013 to February 2015.
756	Climate_change_mitigation	Australia's signed a suicide note [with the Paris Accord] yet didn't seem to notice that China, India, Indonesia and the US did not commit to reducing their large carbon dioxide emissions.	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 .
451	Scuba_diving	The idea that the much smaller carbon dioxide cycle is now controlling the water cycle is not very likely.	Scuba diving Scuba diving is a mode of underwater diving in which the scuba diver uses a self-contained underwater breathing apparatus ( scuba ) which is completely independent of surface supply , to breathe underwater . Unlike other modes of diving , which rely either on breath-hold or on breathing supplied under pressure from the surface , scuba divers carry their own source of breathing gas , usually compressed air , allowing them greater freedom of movement than with an air line or diver 's umbilical and longer underwater endurance than breath-hold . Open circuit scuba systems discharge the breathing gas into the environment as it is exhaled , and consist of one or more diving cylinders containing breathing gas at high pressure which is supplied to the diver through a diving regulator . They may include additional cylinders for decompression gas or emergency breathing gas . Closed-circuit or semi-closed circuit rebreather scuba systems allow recycling of exhaled gases . The volume of gas used is reduced compared to that of open circuit ; therefore , a smaller cylinder or cylinders , may be used for an equivalent dive duration . Rebreathers extend the time spent underwater compared to open circuit for the same gas consumption , they produce fewer bubbles and less noise than scuba which makes them attractive to covert military divers to avoid detection , scientific divers to avoid disturbing marine animals , and media divers to avoid bubble interference . Scuba diving may be done recreationally or professionally in a number of applications , including scientific , military and public safety roles , but most commercial diving uses surface-supplied diving equipment when this is practicable . Scuba divers engaged in armed forces covert operations may be referred to as frogmen , combat divers or attack swimmers . A scuba diver primarily moves underwater by using fins attached to the feet , but external propulsion can be provided by a diver propulsion vehicle , or a sled pulled from the surface . Other equipment includes a dive mask to improve underwater vision , a protective diving suit , equipment to control buoyancy , and equipment related to the specific circumstances and purpose of the dive . Scuba divers are trained in the procedures and skills appropriate to their level of certification by instructors affiliated to the diver certification organisations which issue these certifications . These include standard operating procedures for using the equipment and dealing with the general hazards of the underwater environment , and emergency procedures for self-help and assistance of a similarly equipped diver experiencing problems . A minimum level of fitness and health is required by most training organisations , but a higher level of fitness may be appropriate for some applications .
1049	New_Orleans	So far this month, there have been nearly 5,000 daily record highs set or tied, compared to just 42 daily record lows.	New Orleans New Orleans ( -LSB- nuː_ˈɔːrlᵻnz , _ - ˈɔːrli.ənz , _ - ɔːrˈliːnz -RSB- , or -LSB- ˈnɔːrlᵻnz -RSB- La Nouvelle-Orléans -LSB- la nuvɛlɔʁleɑ̃ -RSB- ) is a major United States port and the largest city and metropolitan area in the state of Louisiana . The population of the city was 343,829 as of the 2010 U.S. Census . The New Orleans metropolitan area ( New Orleans -- Metairie -- Kenner Metropolitan Statistical Area ) had a population of 1,167,764 in 2010 and was the 46th largest in the United States . The New Orleans -- Metairie -- Bogalusa Combined Statistical Area , a larger trading area , had a 2010 population of 1,452,502 . It is well known for its distinct French and Spanish Creole architecture , as well as its cross-cultural and multilingual heritage . New Orleans is also famous for its cuisine , music ( particularly as the birthplace of jazz ) , and its annual celebrations and festivals , most notably Mardi Gras , dating to French colonial times . The city is often referred to as the `` most unique '' in the United States . New Orleans is located in southeastern Louisiana , straddling the Mississippi River . The city and Orleans Parish ( paroisse d'Orléans ) are coterminous . The city and parish are bounded by the parishes of St. Tammany to the north , St. Bernard to the east , Plaquemines to the south , and Jefferson to the south and west . Lake Pontchartrain , part of which is included in the city limits , lies to the north and Lake Borgne lies to the east . Before Hurricane Katrina , Orleans Parish was the most populous parish in Louisiana . As of 2015 , it ranks third in population , trailing neighboring Jefferson Parish , and East Baton Rouge Parish .
809	California	In the early 20th century, state and federal governments began aggressively fighting wildfires and trying to keep them as small as possible.	California California ( -LSB- kælᵻˈfɔːrnjə , _ - ni.ə -RSB- , ) is the most populous state in the United States and the third most extensive by area . Located on the western ( Pacific Ocean ) coast of the U.S. , California is bordered by the other U.S. states of Oregon , Nevada , and Arizona and shares an international border with the Mexican state of Baja California . The state capital is Sacramento . Los Angeles is California 's most populous city , and the country 's second largest after New York City . The Greater Los Angeles Area and the San Francisco Bay Area are the nation 's second - and fifth-most populous urban regions , respectively . California also has the nation 's most populous county , Los Angeles County , and its largest county by area , San Bernardino County . California 's diverse geography ranges from the Pacific Coast in the west to the Sierra Nevada mountain range in the east ; and from the redwood -- Douglas fir forests in the northwest to the Mojave Desert in the southeast . The Central Valley , a major agricultural area , dominates the state 's center . Though California is well-known for its warm Mediterranean climate , the large size of the state means it can vary from moist temperate rainforest in the north , to arid desert in the interior , as well as snowy alpine in the mountains . What is now California was first settled by various Native American tribes before being explored by a number of European expeditions during the 16th and 17th centuries . The Spanish Empire then claimed it as part of Alta California in their New Spain colony . The area became a part of Mexico in 1821 following its successful war for independence , but was ceded to the United States in 1848 after the Mexican -- American War . The western portion of Alta California then was organized as the State of California , and admitted as the 31st state on September 9 , 1850 . The California Gold Rush starting in 1848 led to dramatic social and demographic changes , with large-scale emigration from the east and abroad with an accompanying economic boom . If it were a country , California would be the 6th largest economy in the world and the 35th most populous . It is also regarded as a global trendsetter in both popular culture and politics , and is the origin of the film industry , the hippie counterculture , the Internet , and the personal computer , among others . Fifty-eight percent of the state 's economy is centered on finance , government , real estate services , technology , and professional , scientific and technical business services . The San Francisco Bay Area has the nation 's highest median household income by metropolitan area , and is the headquarters of three of the world 's largest 40 firms by revenue , Chevron , Apple , and McKesson . Although it accounts for only 1.5 percent of the state 's economy , California 's agriculture industry has the highest output of any U.S. state .
1407	Tropical_cyclone	"In their award winning book, 'Taken By Storm' (2007), Canadian researchers Christopher Essex and Ross McKitrick explain: 'Temperature is not an amount of something [like height or weight].	Tropical cyclone A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center , a closed low-level atmospheric circulation , strong winds , and a spiral arrangement of thunderstorms that produce heavy rain . Depending on its location and strength , a tropical cyclone is referred to by names such as hurricane ( -LSB- ˈhʌrᵻkən -RSB- or -LSB- ˈhʌrᵻkeɪn -RSB- ) , typhoon -LSB- taɪ ` fuːn -RSB- , tropical storm , cyclonic storm , tropical depression , and simply cyclone . A hurricane is a storm that occurs in the Atlantic Ocean and northeastern Pacific Ocean , a typhoon occurs in the northwestern Pacific Ocean , and a cyclone occurs in the south Pacific or Indian Ocean . Tropical cyclones typically form over large bodies of relatively warm water . They derive their energy through the evaporation of water from the ocean surface , which ultimately recondenses into clouds and rain when moist air rises and cools to saturation . This energy source differs from that of mid-latitude cyclonic storms , such as nor'easter s and European windstorms , which are fueled primarily by horizontal temperature contrasts . The strong rotating winds of a tropical cyclone are a result of the conservation of angular momentum imparted by the Earth 's rotation as air flows inwards toward the axis of rotation . As a result , they rarely form within 5 ° of the equator . Tropical cyclones are typically between 100 and in diameter . Tropical refers to the geographical origin of these systems , which form almost exclusively over tropical seas . Cyclone refers to their cyclonic nature , with wind blowing counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere . The opposite direction of circulation is due to the Coriolis effect . In addition to strong winds and rain , tropical cyclones are capable of generating high waves , damaging storm surge , and tornadoes . They typically weaken rapidly over land where they are cut off from their primary energy source . For this reason , coastal regions are particularly vulnerable to damage from a tropical cyclone as compared to inland regions . Heavy rains , however , can cause significant flooding inland , and storm surges can produce extensive coastal flooding up to 40 km from the coastline . Though their effects on human populations are often devastating , tropical cyclones can relieve drought conditions . They also carry heat energy away from the tropics and transport it toward temperate latitudes , which may play an important role in modulating regional and global climate .
575	Effects_of_global_warming_on_human_health	While an isolated heatwave can be put down as an anomaly, the scale of this phenomenon points to global warming as the culprit, scientists said.	Effects of global warming on human health The effects of global warming include effects on human health . The observed and projected increased frequency and severity of climate related impacts will further exacerbate the effects on human health . This article describes some of those effects on individuals and populations .
1119	Greenland	Prof Adam Scaife, a climate modelling expert at the UK's Met Office, said the evidence for a link to shrinking Arctic ice was now good: 'The consensus points towards that being a real effect.'"	Greenland Greenland ( -LSB- ˈɡriːnlənd -RSB- Kalaallit Nunaat -LSB- kaˈlaːɬit ˈnunaːt -RSB- Grønland -LSB- ˈɡ̊ʁɶnˌlanˀ -RSB- ) is an autonomous constituent country within the Kingdom of Denmark between the Arctic and Atlantic Oceans , east of the Canadian Arctic Archipelago . Though physiographically a part of the continent of North America , Greenland has been politically and culturally associated with Europe ( specifically Norway and Denmark , the colonial powers , as well as the nearby island of Iceland ) for more than a millennium . The majority of its residents are Inuit , whose ancestors began migrating from the Canadian mainland in the 13th century , gradually settling across the island . Greenland is the world 's largest island ( Australia , although larger , is generally considered to be a continental landmass rather than an island ) . Three-quarters of Greenland is covered by the only permanent ice sheet outside Antarctica . With a population of about 56,480 ( 2013 ) , it is the least densely populated country in the world . The Arctic Umiaq Line ferry acts as a lifeline for western Greenland , connecting the various cities and settlements . Greenland has been inhabited off and on for at least the last 4,500 years by Arctic peoples whose forebears migrated there from what is now Canada . Norsemen settled the uninhabited southern part of Greenland beginning in the 10th century , and Inuit peoples arrived in the 13th century . The Norse colonies disappeared in the late 15th century . Soon after their demise , beginning in 1499 , the Portuguese briefly explored and claimed the island , naming it Terra do Lavrador ( later applied to Labrador in Canada ) . In the early 18th century , Scandinavian explorers reached Greenland again . To strengthen trading and power , Denmark-Norway affirmed sovereignty over the island . Denmark -- Norway claimed Greenland for centuries . Greenland was settled by Vikings ( of Norwegian origin ) more than a thousand years ago , who had previously settled Iceland to escape persecution from the King of Norway and his central government . Vikings set sail from Greenland and Iceland , encountering North America nearly 500 years before Columbus reached the Caribbean islands . They attempted to colonize land . Though under continuous influence of Norway and Norwegians , Greenland was not formally under the Norwegian crown until 1262 . The Kingdom of Norway was extensive and a military power until the mid-14th century . Norway was dramatically hit with a larger death toll than Denmark by the Black Death , forcing Norway to accept a union in which the central government , university and other fundamental institutions were located in Copenhagen . Thus , the two kingdoms ' resources were directed at creating Copenhagen . Norway became the weaker part and lost sovereignty over Greenland in 1814 when the union was dissolved . Greenland became a Danish colony in 1814 , and was made a part of the Danish Realm in 1953 under the Constitution of Denmark . In 1973 , Greenland joined the European Economic Community with Denmark . However , in a referendum in 1982 , a majority of the population voted for Greenland to withdraw from the EEC which was effected in 1985 . Greenland contains the world 's largest and most northernly national park , Northeast Greenland National Park ( Kalaallit Nunaanni nuna eqqissisimatitaq ) . Established in 1974 and expanded to its present size in 1988 , it protects 972001 km2 of the interior and northeastern coast of Greenland and is bigger than all but twenty-nine countries in the world . Greenland is divided into four municipalities - Sermersooq , Kujalleq , Qaasuitsup , and Qeqqata . In 1979 , Denmark had granted home rule to Greenland , and in 2008 , Greenlanders voted in favour of the Self-Government Act , which transferred more power from the Danish royal government to the local Greenlandic government . Under the new structure , in effect since 21 June 2009 , Greenland can gradually assume responsibility for policing , judicial system , company law , accounting , and auditing ; mineral resource activities ; aviation ; law of legal capacity , family law and succession law ; aliens and border controls ; the working environment ; and financial regulation and supervision , while the Danish government retains control of foreign affairs and defence . It also retains control of monetary policy , providing an initial annual subsidy of DKK 3.4 billion , which is planned to diminish gradually over time . Greenland expects to grow its economy based on increased income from the extraction of natural resources . The capital , Nuuk , held the 2016 Arctic Winter Games . At 70 % , Greenland has one of the highest shares of renewable energy in the world , mostly coming from hydropower .
1896	Reforestation	Greg Hunt CSIRO research shows carbon emissions can be reduced by 20 per cent over 40 years using nature, soils and trees.	Reforestation Reforestation is the natural or intentional restocking of existing forests and woodlands that have been depleted , usually through deforestation . Reforestation can be used to rectify or improve the quality of human life by soaking up pollution and dust from the air , rebuild natural habitats and ecosystems , mitigate global warming since forests facilitate biosequestration of atmospheric carbon dioxide , and harvest for resources , particularly timber , but also non-timber forest products . The term reforestation is similar to afforestation , the process of restoring and recreating areas of woodlands or forests that may have existed long ago but were deforested or otherwise removed at some point in the past . Sometimes the term re-afforestation is used to distinguish between the original forest cover and the later re-growth of forest to an area . Forestation is the establishment of forest growth on areas that either had forest or lacked it . Special tools , e.g. tree planting bars , are used to make planting of trees easier and faster .
1138	La_Niña	Stress from unusually warm ocean water heated by man-made climate change and the natural El Niño climate pattern caused the die-off.	La Niña La Niña ( -LSB- lɑːˈniːnjə -RSB- , -LSB- la ˈniɲa -RSB- ) is a coupled ocean-atmosphere phenomenon that is the counterpart of El Niño as part of the broader El Niño -- Southern Oscillation climate pattern . The name La Niña originates from Spanish , meaning `` the little girl '' , analogous to El Niño meaning `` the little boy '' . It has also in the past been called anti-El Niño , and El Viejo ( meaning `` the old man '' ) . During a period of La Niña , the sea surface temperature across the equatorial Eastern Central Pacific Ocean will be lower than normal by 3 to 5 ° C . In the United States , an appearance of La Niña persists for at least five months . It has extensive effects on the weather in North America , even affecting the Atlantic Hurricane Season .
2744	Urban_heat_island	Dropped stations show more warming than kept stations.	Urban heat island An urban heat island ( UHI ) is an urban area or metropolitan area that is significantly warmer than its surrounding rural areas due to human activities . The temperature difference usually is larger at night than during the day , and is most apparent when winds are weak . UHI is most noticeable during the summer and winter . The main cause of the urban heat island effect is from the modification of land surfaces . Waste heat generated by energy usage is a secondary contributor . As a population center grows , it tends to expand its area and increase its average temperature . The less-used term heat island refers to any area , populated or not , which is consistently hotter than the surrounding area . Monthly rainfall is greater downwind of cities , partially due to the UHI . Increases in heat within urban centers increases the length of growing seasons , and decreases the occurrence of weak tornadoes . The UHI decreases air quality by increasing the production of pollutants such as ozone , and decreases water quality as warmer waters flow into area streams and put stress on their ecosystems . Not all cities have a distinct urban heat island . Mitigation of the urban heat island effect can be accomplished through the use of green roofs and the use of lighter-colored surfaces in urban areas , which reflect more sunlight and absorb less heat . There are concerns raised about possible contribution from urban heat islands to global warming . Research on China and India indicates that urban heat island effect contributes to climate warming by about 30 % . On the other hand , one 1999 comparison between urban and rural areas proposed that the urban heat island effects have little influence on global mean temperature trends . Many studies reveal increases in the severity of the effect with the progress of climate change .
492	Global_warming	But like most claims regarding global warming, the real effect is small, probably temporary, and most likely due to natural weather patterns	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 .
2844	Econometrics	The claim sea level isn't rising is based on blatantly doctored graphs and conspiracy theories that are contradicted by empirical observational data.	Econometrics Econometrics is the application of statistical methods to economic data and is described as the branch of economics that aims to give empirical content to economic relations . More precisely , it is `` the quantitative analysis of actual economic phenomena based on the concurrent development of theory and observation , related by appropriate methods of inference . '' An introductory economics textbook describes econometrics as allowing economists `` to sift through mountains of data to extract simple relationships . '' The first known use of the term `` econometrics '' ( in cognate form ) was by Polish economist Paweł Ciompa in 1910 . Ragnar Frisch is credited with coining the term in the sense in which it is used today . The basic tool for econometrics is the multiple linear regression model . Econometric theory uses statistical theory and mathematical statistics to evaluate and develop econometric methods . Econometricians try to find estimators that have desirable statistical properties including unbiasedness , efficiency , and consistency . Applied econometrics uses theoretical econometrics and real-world data for assessing economic theories , developing econometric models , analyzing economic history , and forecasting .
2774	20th_century	Actual reconstructions "diverge" from the instrumental series in the last part of 20th 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 ) .
1430	Constanța	Seventeen of the 18 warmest years have occurred since 2000.	Constanța Constanța ( -LSB- konˈstant͡sa -RSB- ) , historically known as Tomis ( Κωνστάντζα or Κωνστάντια , Konstantia , Кюстенджа or Констанца , Köstence ) , is the oldest continuously inhabited city in Romania . It was founded around 600 BC . The city is located in the Dobruja region of Romania , on the Black Sea coast . It is the capital of Constanța County and the largest city in the region . As of the 2011 census , Constanța has a population of 283,872 , making it the fifth most populous city in Romania . The Constanța metropolitan area includes 14 localities within 30 km of the city , and , with 425,916 inhabitants , it is the second largest metropolitan area in Romania . The Port of Constanța has an area of 39.26 km2 and a length of about 30 km . It is the largest port on the Black Sea , and one of the largest ports in Europe .
2464	Attribution_of_recent_climate_change	While natural forcings can account for much of the early 20th Century warming, humans played a role as well.	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 ) .
2424	Arctic_sea_ice_decline	Consequently, the total amount of Arctic sea ice in 2008 and 2009 are the lowest on record.	Arctic sea ice decline Arctic sea ice decline is the sea ice loss observed in recent decades in the Arctic Ocean . The Intergovernmental Panel on Climate Change ( IPCC ) Fourth Assessment Report states that greenhouse gas forcing is largely , but not wholly , responsible for the decline in Arctic sea ice extent . A study from 2011 suggested that internal variability enhanced the greenhouse gas forced sea ice decline over the last decades . A study from 2007 found the decline to be `` faster than forecasted '' by model simulations . The IPCC Fifth Assessment Report concluded with high confidence that sea ice continues to decrease in extent , and that there is robust evidence for the downward trend in Arctic summer sea ice extent since 1979 . It has been established that the region is at its warmest for at least 40,000 years and the Arctic-wide melt season has lengthened at a rate of 5 days per decade ( from 1979 to 2013 ) , dominated by a later autumn freezeup . Sea ice changes have been identified as a mechanism for polar amplification .
2168	Intergovernmental_Panel_on_Climate_Change	IPCC graph showing accelerating trends is misleading	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 .
916	Antarctica	The acceleration is making some scientists fear that Antarctica's ice sheet may have entered the early stages of an unstoppable disintegration.	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 .
2898	Retreat_of_glaciers_since_1850	The report suggests significantly smaller overall ice-mass losses than previous estimates.	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 .
2091	Atmospheric_methane	Water vapor is the most powerful greenhouse gas	Atmospheric methane Atmospheric methane is the methane present in Earth 's atmosphere . Atmospheric methane concentrations are of interest because it is one of the most potent greenhouse gases in Earth 's atmosphere . The 100-year global warming potential of methane is 28 . That is , over a 100-year period , it traps 28 times more heat per mass unit than carbon dioxide and 32 times the effect when accounted for aerosol interactions . Global methane levels , had risen to 1800 parts per billion ( ppb ) by 2011 , an increase by a factor of 2.5 since pre-industrial times , from 722 ppb , the highest value in at least 800,000 years . Its concentration is higher in the Northern Hemisphere since most sources ( both natural and human ) are located on land and the Northern Hemisphere has more land mass . The concentrations vary seasonally , with , for example , a minimum in the northern tropics during April − May mainly due to removal by the hydroxyl radical . Early in the Earth 's history carbon dioxide and methane likely produced a greenhouse effect . The carbon dioxide would have been produced by volcanoes and the methane by early microbes . During this time , Earth 's earliest life appeared . These first , ancient bacteria added to the methane concentration by converting hydrogen and carbon dioxide into methane and water . Oxygen did not become a major part of the atmosphere until photosynthetic organisms evolved later in Earth 's history . With no oxygen , methane stayed in the atmosphere longer and at higher concentrations than it does today . Methane is created near the surface , and it is carried into the stratosphere by rising air in the tropics . Uncontrolled build-up of methane in Earth 's atmosphere is naturally checked -- although human influence can upset this natural regulation -- by methane 's reaction with hydroxyl radicals formed from singlet oxygen atoms and with water vapor .
1640	Scientific_consensus_on_climate_change	Recent studies agree that recent global temperatures are unprecedented in the last 1000 years.	Scientific consensus on climate change There is currently a strong scientific consensus that the Earth is warming and that this warming is mainly caused by human activities. This consensus is supported by various studies of scientists' opinions and by position statements of scientific organizations, many of which explicitly agree with the Intergovernmental Panel on Climate Change (IPCC) synthesis reports. Nearly all actively publishing climate scientists (97–98%) support the consensus on anthropogenic climate change, and the remaining 2% of contrarian studies either cannot be replicated or contain errors.
490	United_Nations_Framework_Convention_on_Climate_Change	IPCC report warning last week the world is "nowhere near on track" to meet its Paris commitments	United Nations Framework Convention on Climate Change The United Nations Framework Convention on Climate Change ( UNFCCC ) is an international environmental treaty adopted on May 9 , 1992 and opened for signature at the Earth Summit in Rio de Janeiro from 3 to 14 June 1992 . It then entered into force on 21 March 1994 , after a sufficient number of countries had ratified it . The UNFCCC objective is to `` stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system '' . The framework sets no binding limits on greenhouse gas emissions for individual countries and contains no enforcement mechanisms . Instead , the framework outlines how specific international treaties ( called `` protocols '' or `` Agreements '' ) may be negotiated to specify further action towards the objective of the UNFCCC . Initially an Intergovernmental Negotiating Committee ( INC ) produced the text of the Framework Convention during its meeting in New York from 30 April to 9 May 1992 . The UNFCCC was adopted on 9 May 1992 , and opened for signature on 4 June 1992 . The UNFCCC has 197 parties as of December 2015 . The convention enjoys broad legitimacy , largely due to its nearly universal membership . The parties to the convention have met annually from 1995 in Conferences of the Parties ( COP ) to assess progress in dealing with climate change . In 1997 , the Kyoto Protocol was concluded and established legally binding obligations for developed countries to reduce their greenhouse gas emissions in the period 2008-2012 . The 2010 Cancún agreements state that future global warming should be limited to below 2.0 ° C ( 3.6 ° F ) relative to the pre-industrial level . The Protocol was amended in 2012 to encompass the period 2013-2020 in the Doha Amendment , which - as of December 2015 - had not entered into force . In 2015 the Paris Agreement was adopted , governing emission reductions from 2020 on through commitments of countries in ambitious Nationally Determined Contributions . The Paris Agreement entered into force on November 4th , 2016 . One of the first tasks set by the UNFCCC was for signatory nations to establish national greenhouse gas inventories of greenhouse gas ( GHG ) emissions and removals , which were used to create the 1990 benchmark levels for accession of Annex I countries to the Kyoto Protocol and for the commitment of those countries to GHG reductions . Updated inventories must be submitted annually by Annex I countries . The UNFCCC is also the name of the United Nations Secretariat charged with supporting the operation of the Convention , with offices in Haus Carstanjen , and the UN Campus ( known as Langer Eugen ) Bonn , Germany . From 2010 to 2016 the head of the secretariat was Christiana Figueres . In July 2016 , Patricia Espinosa from Mexico succeeded Figueres . The Secretariat , augmented through the parallel efforts of the Intergovernmental Panel on Climate Change ( IPCC ) , aims to gain consensus through meetings and the discussion of various strategies .
2903	SeaLifeBase	The interesting point is that it also seems each time they come across a new dataset it is simply replaced.	SeaLifeBase SeaLifeBase is a global online database of information about marine life . It aims to provide key information on the taxonomy , distribution and ecology of all marine species in the world apart from finfish . SeaLifeBase is in partnership with the WorldFish Center in Malaysia and the UBC Fisheries Centre at the University of British Columbia . Daniel Pauly is the principal investigator and it is coordinated by Maria Lourdes D. Palomares . , it included descriptions of 74,000 species , 47,700 common names , 12,400 pictures , and references to 31,700 works in the scientific literature . SeaLifeBase complements FishBase , which provides parallel information for finfish .
806	2010_Northern_Hemisphere_heat_waves	Days of near-100-degree-Fahrenheit temperatures cooked the Mountain West in early July, and a scorching heat wave lingered over the Pacific Northwest in early August."	2010 Northern Hemisphere heat waves The 2010 Northern Hemisphere summer heat waves included severe heat waves that impacted most of the United States, Kazakhstan, Mongolia, China, Hong Kong, North Africa and the European continent as a whole, along with parts of Canada, Russia, Indochina, South Korea and Japan during May, June, July, and August 2010. The first phase of the global heatwaves was caused by a moderate El Niño event, which lasted from June 2009 to May 2010. The first phase lasted only from April 2010 to June 2010, and caused only moderate above average temperatures in the areas affected. But it also set new record high temperatures for most of the area affected, in the Northern Hemisphere. The second phase (the main, and most devastating phase) was caused by a very strong La Niña event, which lasted from June 2010 to June 2011. According to meteorologists, the 2010–11 La Niña event was one of the strongest La Niña events ever observed. That same La Niña event also had devastating effects in the Eastern states of Australia. The second phase lasted from June 2010 to October 2010, caused severe heat waves, and multiple record-breaking temperatures. The heatwaves began on April 2010, when strong anticyclones began to develop, over most of the affected regions, in the Northern Hemisphere. The heatwaves ended in October 2010, when the powerful anticyclones over most of the affected areas dissipated. The heat wave during the summer of 2010 was at its worst in June, over the Eastern United States, Middle East, Eastern Europe and European Russia, and over Northeastern China and southeastern Russia. June 2010 marked the fourth consecutive warmest month on record globally, at 0.66 °C (1.22 °F) above average, while the period April–June was the warmest ever recorded for land areas in the Northern Hemisphere, at 1.25 °C (2.25 °F) above average. The previous record for the global average temperature in June was set in 2005 at 0.66 °C (1.19 °F), and the previous warm record for April–June over Northern Hemisphere land areas was 1.16 °C (2.09 °F), set in 2007. The strongest of the anticyclones, the one situated over Siberia, registered a maximum high pressure of 1040 millibars. The weather caused forest fires in China, where three in a team of 300 died fighting a fire that broke out in the Binchuan County of Dali, as Yunnan suffered the worst drought in 60 years by February 17. A major drought was reported across the Sahel as early as January. In August, a section of the Petermann Glacier tongue connecting northern Greenland, the Nares Strait and the Arctic Ocean broke off, the biggest ice shelf in the Arctic to detach in 48 years. By the time the heatwaves had ended in late October 2010, about $500 billion (2011 USD) of damage was done, in the Northern Hemisphere alone. The World Meteorological Organization stated that the heat waves, droughts and flooding events fit with predictions based on global warming for the 21st century, include those based on the Intergovernmental Panel on Climate Change's 2007 4th Assessment Report. Some climatologists argue that these weather events would not have happened if the atmospheric carbon dioxide was at pre-industrial levels.
1333	Sea	"The oceans will never become acid because there is such a huge buffering capacity in the oceans.	Sea A sea is a large body of salt water that is surrounded in whole or in part by land . More broadly , `` the sea '' is the interconnected system of Earth 's salty , oceanic waters -- considered as one global ocean or as several principal oceanic divisions . The sea moderates Earth 's climate and has important roles in the water cycle , carbon cycle , and nitrogen cycle . Although the sea has been traveled and explored since prehistory , the modern scientific study of the sea -- oceanography -- dates broadly to the British Challenger expedition of the 1870s . The sea is conventionally divided into up to five large oceanic sections -- including the International Hydrographic Organization 's four named oceans ( the Atlantic , Pacific , Indian , and Arctic ) and the Southern Ocean ; smaller , second-order sections , such as the Mediterranean , are known as seas . Owing to the present state of continental drift , the Northern Hemisphere is now fairly equally divided between land and sea ( a ratio of about 2:3 ) but the South is overwhelmingly oceanic ( 1:4.7 ) . Salinity in the open ocean is generally in a narrow band around 3.5 % by mass , although this can vary in more landlocked waters , near the mouths of large rivers , or at great depths . About 85 % of the solids in the open sea are sodium chloride . Deep-sea currents are produced by differences in salinity and temperature . Surface currents are formed by the friction of waves produced by the wind and by tides , the changes in local sea level produced by the gravity of the Moon and Sun . The direction of all of these is governed by surface and submarine land masses and by the rotation of the Earth ( the Coriolis effect ) . Former changes in sea levels have left continental shelves , shallow areas in the sea close to land . These nutrient-rich waters teem with life , which provide humans with substantial supplies of food -- mainly fish , but also shellfish , mammals , and seaweed -- which are both harvested in the wild and farmed . The most diverse areas surround great tropical coral reefs . Whaling in the deep sea was once common but whales ' dwindling numbers prompted international conservation efforts and finally a moratorium on most commercial hunting . Oceanography has established that not all life is restricted to the sunlit surface waters : even under enormous depths and pressures , nutrients streaming from hydrothermal vents support their own unique ecosystem . Life may have started there and aquatic microbial mats are generally credited with the oxygenation of Earth 's atmosphere ; both plants and animals first evolved in the sea . The sea is an essential aspect of human trade , travel , mineral extraction , and power generation . This has also made it essential to warfare and left major cities exposed to earthquakes and volcanoes from nearby faults ; powerful tsunami waves ; and hurricanes , typhoons , and cyclones produced in the tropics . This importance and duality has affected human culture , from early sea gods to the epic poetry of Homer to the changes induced by the Columbian Exchange , from burial at sea to Basho 's haikus to hyperrealist marine art , and inspiring music ranging from the shanties in The Complaynt of Scotland to Rimsky-Korsakov 's `` The Sea and Sinbad 's Ship '' to A-mei 's `` Listen to the Sea '' . It is the scene of leisure activities including swimming , diving , surfing , and sailing . However , population growth , industrialization , and intensive farming have all contributed to present-day marine pollution . Atmospheric carbon dioxide is being absorbed in increasing amounts , lowering its pH in a process known as ocean acidification . The shared nature of the sea has made overfishing an increasing problem .
904	Carbon_dioxide	Without human intervention, the concentration of CO2 has climbed as high as 7,000 parts per million (ppm) in prior eras, whereas at present the concentration is just over 400 ppm.	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 .
74	Global_warming	The models predicted about three times the amount of warming in the world we've seen since [1988].	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 .
38	Sea_level_rise	Scientists studying Antarctica sea ice warn a rise in accumulation could spark the next ice age.	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 .
1952	Arctic_sea_ice_decline	Scientists project that the Arctic will be ice-free in the summer of 2013.	Arctic sea ice decline Arctic sea ice decline is the sea ice loss observed in recent decades in the Arctic Ocean . The Intergovernmental Panel on Climate Change ( IPCC ) Fourth Assessment Report states that greenhouse gas forcing is largely , but not wholly , responsible for the decline in Arctic sea ice extent . A study from 2011 suggested that internal variability enhanced the greenhouse gas forced sea ice decline over the last decades . A study from 2007 found the decline to be `` faster than forecasted '' by model simulations . The IPCC Fifth Assessment Report concluded with high confidence that sea ice continues to decrease in extent , and that there is robust evidence for the downward trend in Arctic summer sea ice extent since 1979 . It has been established that the region is at its warmest for at least 40,000 years and the Arctic-wide melt season has lengthened at a rate of 5 days per decade ( from 1979 to 2013 ) , dominated by a later autumn freezeup . Sea ice changes have been identified as a mechanism for polar amplification .

Subsets and Splits

No community queries yet

The top public SQL queries from the community will appear here once available.