query: "the temperature increase in the second half of the 20th century could have taken place in steps driven by major ENSO events" (Jens Raunsø Jensen)

positive: 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 ) .

positive: El Niño–Southern Oscillation El Niño -- Southern Oscillation ( ENSO ) is an irregularly periodical variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean , affecting much of the tropics and subtropics . The warming phase is known as El Niño and the cooling phase as La Niña . Southern Oscillation is the accompanying atmospheric component , coupled with the sea temperature change : El Niño is accompanied with high , and La Niña with low air surface pressure in the tropical western Pacific . The two periods last several months each ( typically occur every few years ) and their effects vary in intensity .   The two phases relate to the Walker circulation , discovered by Gilbert Walker during the early twentieth century . The Walker circulation is caused by the pressure gradient force that results from a high pressure system over the eastern Pacific Ocean , and a low pressure system over Indonesia . When the Walker circulation weakens or reverses , an El Niño results , causing the ocean surface to be warmer than average , as upwelling of cold water occurs less or not at all . An especially strong Walker circulation causes a La Niña , resulting in cooler ocean temperatures due to increased upwelling .   Mechanisms that cause the oscillation remain under study . The extremes of this climate pattern 's oscillations cause extreme weather ( such as floods and droughts ) in many regions of the world . Developing countries dependent upon agriculture and fishing , particularly those bordering the Pacific Ocean , are the most affected .

positive: 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 .

negative: Jens Jensen Summer House and Studio The Jens Jensen Summer House and Studio at 930-950 Dean Ave. in Highland Park , Illinois is associated with landscape architect Jens Jensen . It was listed on the National Register of Historic Places in 1991 .

negative: Jens Jensen Jens Jensen may refer to :   Jens Jensen ( politician ) ( 1865 -- 1936 ) , Australian politician  Jens Jensen ( landscape architect ) ( 1860 -- 1951 ) , Danish born landscape architect in Chicago , Illinois  Jens Kristian Jensen ( 1885 -- 1956 ) , Danish gymnast and Olympic medalist  ( 1890 -- 1957 ) , Danish football ( soccer ) player who played one game for the Denmark national football team  Jens Jensen ( trade unionist ) ( 1859 -- 1928 ) , Danish trade unionist and Social Democratic politician  Jens S. Jensen ( 1946 -- 2015 ) , Swedish photographer and writer

negative: Jens Nygård (sport shooter) Jens Jensen Nygård ( 7 August 1934 -- 3 September 2005 ) was a Norwegian sports shooter . He placed 69th in the 50 metre rifle , prone event at the 1972 Summer Olympics .

negative: Jens Billes visebog Jens Billes visebog ( ` Jens Bille 's song-book ' , Odense , Landsarkivet for Fyn , Karen Brahe E I ,2 , also called ` Jens Billes håndskrift ' and ` Jens Billes poesiebog ' and once known as ` Steen Billes Haandskrift ' ) is the second oldest major collection of Danish poetry , after the Heart Book . It was compiled in the second half of the 1550s .

negative: Jens Jensen (landscape architect) Jens Jensen ( September 13 , 1860 - October 1 , 1951 ) was a Danish-American landscape architect .

negative: Jens Kristian Jensen Jens Kristian Jensen ( 22 March 1885 -- 27 March 1956 ) was a Danish gymnast who competed in the 1912 Summer Olympics .   He was part of the Danish team , which won the silver medal in the gymnastics men 's team , Swedish system event .

negative: Japanese settlement in Kiribati Japanese presence in Kiribati dates back to the 20th century when labourers were hired to work in Kiribati 's phosphate mines . As compared to the other Micronesian countries which came under Japanese rule in the first half of the 20th century , the majority of the Japanese consisted of transient workers and only a few settled in Kiribati . Since Kiribati became independent in 1978 , a few Japanese have also taken permanent residence in Kiribati , and assumed important positions within Gilbertese society .

negative: Emigration from Kosovo A substantial emigration from Kosovo has been taken place in various phases during the second half of the 20th century . It is estimated that about a third of people of Kosovan descent currently live outside of Kosovo . Emigration has taken place in separate waves motivated mainly by economic reasons , but also as a result of the Kosovo War . The Kosovo diaspora is usually included in the wider Albanian diaspora with Albanians from Albania and Macedonia .

negative: Adolf Ellegard Jensen Adolf Ellegard Jensen ( 1 January 1899 in Kiel - 20 May 1965 in Mammolshain , Taunus ) was one of the most important German ethnologists of the first half of the 20th century .   Jensen 's main research interests were myth , ritual and cult . He furthered the theory of Cultural Morphology founded by Leo Frobenius . Jensen is mostly known for his research on religious sacrifice that led him to the introduction of the concept of Dema Deity . His best-known work is ` Myth and Cult Among Primitive Peoples ' , published in 1951 .

negative: Vapor-compression evaporation Vapor-compression evaporation is the evaporation method by which a blower , compressor or jet ejector is used to compress , and thus , increase the pressure of the vapor produced . Since the pressure increase of the vapor also generates an increase in the condensation temperature , the same vapor can serve as the heating medium for its `` mother '' liquid or solution being concentrated , from which the vapor was generated to begin with . If no compression was provided , the vapor would be at the same temperature as the boiling liquid/solution , and no heat transfer could take place .   It is also sometimes called vapor compression distillation ( VCD ) . If compression is performed by a mechanically driven compressor or blower , this evaporation process is usually referred to as MVR ( mechanical vapor recompression ) . In case of compression performed by high pressure motive steam ejectors , the process is usually called thermocompression or steam compression .

negative: Major second In Western music theory , a major second ( sometimes also called whole tone ) is a second spanning two semitones . A second is a musical interval encompassing two adjacent staff positions ( see Interval number for more details ) . For example , the interval from C to D is a major second , as the note D lies two semitones above C , and the two notes are notated on adjacent staff positions . Diminished , minor and augmented seconds are notated on adjacent staff positions as well , but consist of a different number of semitones ( zero , one , and three ) .   The major second is the interval that occurs between the first and second degrees of a major scale , the tonic and the supertonic . On a musical keyboard , a major second is the interval between two keys separated by one key , counting white and black keys alike . On a guitar string , it is the interval separated by two frets . In moveable-do solfège , it is the interval between do and re . It is considered a melodic step , as opposed to larger intervals called skips .   Intervals composed of two semitones , such as the major second and the diminished third , are also called tones , whole tones , or whole steps .  One source says step is `` chiefly US . ''  The preferred usage has been argued since the 19th century :  `` Mr. M. in teaching the Diatonic scale calls a tone a step , and a semitone a half step ; now , who ever heard of a step in music , or in sound ? Can any one suppose that a pupil will understand the meaning of tone and semitone any sooner by calling them step or half step , ... ? ''  '' ... to use the term tone for a whole step is certainly objectionable ... ''  In just intonation , major seconds can occur in at least two different frequency ratios :  9:8 ( about 203.9 cents ) and 10:9 ( about 182.4 cents ) . The largest ( 9:8 ) ones are called major tones or greater tones , the smallest ( 10:9 ) are called minor tones or lesser tones . Their size differs by exactly one syntonic comma ( 81:80 , or about 21.5 cents ) .  Some equal temperaments , such as 15-ET and 22-ET , also distinguish between a greater and a lesser tone .   The major second was historically considered one of the most dissonant intervals of the diatonic scale , although much 20th-century music saw it reimagined as a consonance . It is common in many different musical systems , including Arabic music , Turkish music and music of the Balkans , among others . It occurs in both diatonic and pentatonic scales .   . Here , middle C is followed by D , which is a tone 200 cents sharper than C , and then by both tones together .

negative: Jens S. Jensen Jens Håkan Schleimann-Jensen , known as Jens S. Jensen ( 25 May 1946 -- 1 July 2015 ) was a Swedish photographer and writer . He is mainly known for his depictions of working class life in Gothenburg , Sweden .   The works of Jens S. Jensen are in the collections of the Swedish Centre for Architecture and Design and the Nordic Museum in Stockholm , the Hasselblad Centre in Gothenburg and the Museum of Modern Art in New York .

negative: Jens Fink-Jensen Jens Fink-Jensen ( born December 19 , 1956 ) is a Danish poet , author , photographer , composer and architect .

negative: Pyrotherapy Pyrotherapy ( artificial fever , therapeutic fever ) is a method of treatment by raising the body temperature or sustaining an elevated body temperature ( caused by a fever ) . In general , the body temperature was maintained at 41 ° Celsius ( 105 ° Fahrenheit ) . Many diseases were treated by this method in the first half of the 20th century . In general , it was done by exposing the patient to hot baths , warm air , or ( electric ) blankets .

negative: Oriental Orthodoxy in Germany Oriental Orthodoxy in Germany is part of the Oriental Orthodox Christian tradition . Before the beginning of 20th century , presence of Oriental Orthodox Christianity in Germany was minor , mainly represented by Armenian communities . It was gradually increasing in the second half of the century with immigration , mainly from the region of Middle East . Today , it is a growing community , well integrated into German society .

negative: History of Bangkok The history of the city of Bangkok , in Thailand , dates at least to the early 15th century , when it was under the rule of Ayutthaya . Due to its strategic location near the mouth of the Chao Phraya River , the town gradually increased in importance , and after the fall of Ayutthaya King Taksin established his new capital of Thonburi there , on the river 's western bank . King Phutthayotfa Chulalok , who succeeded Taksin , moved the capital to the eastern bank in 1782 , to which the city dates its foundation under its current Thai name , Krung Thep Maha Nakhon . Bangkok has since undergone tremendous changes , growing rapidly , especially in the second half of the 20th century , to become the primate city of Thailand . It was the centre of Siam 's modernization in the late 19th century , subjected to Allied bombing during the Second World War , and has long been the modern nation 's central political stage , with numerous uprisings and coups d'état having taken place on its streets throughout the years .

negative: Bom-Crioulo Bom-Crioulo : The Black Man and the Cabin Boy ( Bom-Crioulo ) is a novel by the Brazilian writer Adolfo Caminha , first published in 1895 . An English translation by E.A. Lacey was published in 1982 by Gay Sunshine .   The novel was the first major literary work on homosexuality to be published in Brazil , and one of the first to have a black person as its hero . The novel caused a stir upon its publication but was almost forgotten in the first half of the 20th century . In the second half of the 20th century , the novel has been republished several times in Brazil and translated into English , Spanish , German , French and Italian .

negative: Holger J. Jensen Holger Jens Sophus Jensen ( 21 April 1900 -- 24 July 1966 ) was a Danish painter .

negative: Mormonism in the 20th century This is a timeline of major events in Mormonism in the 20th century .  __ NOTOC __

negative: List of states of matter Classically , states of matter are distinguished by changes in specific heat capacity , pressure , and temperature . States are distinguished by a discontinuity in one of those properties : for example , raising the temperature of ice produces a clear discontinuity at 0 ° C as energy goes into phase transition , instead of temperature increase .   In the 20th century , increased understanding of the more exotic properties of matter has resulted in many additional states of matter , none of which are observed in normal conditions .

negative: Hinduism in Wales Hinduism in Wales is of relatively recent provenance , with under half of Welsh Hindus having settled there in the second half of the 20th century . There were 10,434 Hindus in Wales in the 2011 Census , almost double the number in the 2001 census .

negative: W Corvi W Corvi is an eclipsing binary star system in the constellation Corvus , ranging from apparent magnitude 11.16 to 12.5 over 9 hours . Its period has increased by 1/4 second over a century . It is an unusual system in that its two stars are very close to each other yet have different surface temperatures and hence thermal transfer is not taking place as expected .

negative: Cobb School The Cobb School is a historic district schoolhouse at Cobb School Road and Bridgman Hill Road in Hardwick , Vermont . Built in the 1840s , it is a well-preserved example of a Greek Revival district school building . It served as a school until 1946 , aided by modernization steps taken in the early 20th century to maintain state standards . It was listed on the National Register of Historic Places in 1993 .

negative: René Burri René Burri ( 9 April 1933 -- 20 October 2014 ) was a Swiss photographer known for his photos of major political , historical and cultural events and key figures of the second half of the 20th century . Burri worked for Magnum Photos and photographed political , military and artistic figures and scenes since 1946 . He made portraits of Che Guevara and Pablo Picasso as well as iconic pictures of São Paulo and Brasília .

negative: Driven Crazy Driven Crazy is an Australian children 's television series , based on the short stories by author Paul Jennings . It first aired in 1998 , and was the second television series based on his works .

negative: Steam-powered vessels Steam-powered vessels include steamboats and steamships . Smaller steamboats were developed first . They were replaced by larger steamships which were often ocean-going . Steamships required a change in propulsion technology from sail to paddlewheel to screw to steam turbines . The latter innovation changed the design of vessels to one that could move faster through the water . Engine propulsion changed to Steam turbine in the early 20th century . In the latter part of the 20th century , these , in turn , were replaced by gas turbines .   Steamship generally refers to larger steam-powered ships , usually ocean-going , capable of carrying a ( ship 's ) boat . The engine room , to the right , is a concept drawing during the construction of the ship . The term steam wheeler is archaic and rarely used . In England , `` steam packet '' , after its sailing predecessor , was the usual term ; even `` steam barge '' could be used ( Steam tonnage in Lloyd 's Register exceeded sailing ships tonnage by 1865 ) . The French transatlantic steamer was probably the last of her type to be equipped with sails , although she never used them . Steamships in turn were overtaken by diesel-driven ships in the second half of the 20th century . Most warships used steam propulsion from the 1860s until the late 20th century

negative: Hydroelectric power in Colombia With seventy percent of Colombia 's power generation , hydroelectric power is a very important national energy source . The total large hydropower potential for Colombia is estimated at 93GW , with an additional 25GW of small hydropower ( < 20MW ) . However , the potential for large hydropower faces difficulties , as the best sites have already been developed , also due to the escalating environmental and social costs associated with large dams , and the likely impacts of climate change and climate variability on the hydrological regime of the country ( drastic increases in surface temperature in the Andes , changes in precipitation patterns , and increases in the intensity and frequency of El Niño-Southern Oscillation ( ENSO ) signals driving prolonged periods of drought ) .

negative: Drought in Canada Prolonged , large-area droughts are among Canada 's costliest natural disasters having major impacts on a wide range of sectors including agriculture , forestry , industry , municipalities , recreation , human health , society and ecosystems . They frequently stress water availability by depleting soil moisture , reducing stream flows , lowering lake and reservoir levels , and diminishing groundwater supplies . This ultimately affects several economic activities including for example , decreased agricultural production , less hydro-electric power generation , and increased freshwater transportation costs . Droughts also create major environmental hazards such as reduced water quality , wetland loss , soil erosion and degradation , and ecological habitat destruction .   Although most regions of Canada have experienced drought , many of the southern regions of the Canadian Prairies and interior British Columbia are most susceptible . During the past two centuries , at least 40 droughts have occurred in western Canada with multi-year episodes being observed in the 1890s , 1910s , 1930s , 1960s , 1980s , and the early 2000s . Droughts in southern Ontario/Quebec are usually shorter , smaller in area , less frequent , and less intense . Nonetheless , there have been some major drought occurrences there as well during the 20th century . Droughts in the Atlantic Provinces occur even less frequently . Droughts are less of a concern for northern Canada mainly due to their lower population densities . However , increased frequencies of forest fires during drought years can have serious economic impacts .   Rarely has drought been as serious or extensive as the recent 1999-2004 episode . This was the worst drought for at least a hundred years in parts of the Canadian Prairies . Well below normal precipitation was reported in areas of Alberta and Saskatchewan for more than four consecutive years extending from autumn 1999 to spring 2004 . No single year on record between Medicine Hat , Kindersley , and Saskatoon was drier than in 2001 . The years 2001 and 2002 may have also brought the first coast-to-coast droughts on record , and were rare as they struck areas less accustomed to dealing with droughts including parts of Atlantic Canada and the northern agricultural prairies ( see Figure 1 ) . Canada 's Gross Domestic Product fell $ 5.8 billion for 2001 and 2002 . In addition , previously reliable water supplies such as streams , wetlands , reservoirs , and groundwater were placed under stress and often failed . For example , the number of natural Prairie ponds in May 2002 was the lowest on record while in 2001 , Great Lakes-St . Lawrence water levels plunged to their lowest point in more than 30 years , thereby significantly increasing marine transportation costs . In British Columbia and Manitoba , hydro-electric generation was curtailed , necessitating additional purchases of power from neighboring jurisdictions . In 2002 , the incidence of forest fires in Alberta increased to five times the ten-year average while in summer 2003 , populated regions of interior British Columbia were stricken by drought-enhanced fires . Long-lasting impacts include soil degradation by wind erosion and deterioration of grasslands that could take decades and longer to recover .   High surface temperatures intensify droughts by enhancing evapotranspiration in summer , and increasing sublimation and melting of the snowpack during winter . During the 20th century , mean annual air temperature has increased by around 1 ° C over southern Canada with the greatest warming in the west and the largest rates during winter and spring . Over the same period , annual precipitation has significantly increased over most of southern Canada with the exception of southern Alberta and Saskatchewan . Coincident with the large increases in spring temperature , the 1980s to the present have been associated with rapid reductions in snow cover during the second half of the snow season . Over the last 30 to 50 years , average stream flow has decreased in many parts of Canada with significant reductions in the south . Great Lakes ' water levels have shown substantial variability during the 20th century with no evidence of a long-term trend . Lower levels coincided with the droughts of the 1930s , early 1960s , and the recent 1999-2001 dry period . Over the Prairies , the numbers and water levels of wetlands have shown no clear trend over the last 40 to 50 years .   Indices used to measure drought show considerable decadal-scale variability with no long-term trends discernible in any portion of the country . Most southern regions of Canada , however , experienced drought conditions during the late 1990s to early 2000s . The worst and most prolonged Canadian Prairie-wide droughts during the instrumental period occurred in the early part of the 20th century ( 1920s and 1930s ) . Paleo studies over the southwestern Canadian Prairies using tree ring chronologies dating back to 1597 indicate that the 20th century lacked the prolonged droughts of the 18th and 19th Centuries when droughts were evident for decades at a time .

negative: Depolymerization Depolymerization ( or depolymerisation ) is the process of converting a polymer into a monomer or a mixture of monomers . All polymers depolymerize at high temperatures , a process driven by an increase in entropy .

negative: Wenker synthesis The Wenker synthesis is an organic reaction converting a beta amino alcohol to an aziridine with the aid of sulfuric acid .   The original Wenker synthesis of aziridine itself takes place in two steps . In the first step ethanolamine is reacted with sulfuric acid at high temperatures ( 250 ° C ) to form the sulfate mono-ester . This salt is then reacted with sodium hydroxide in the second step forming aziridine . The base abstracts an amine proton enabling it to displace the sulfate group . A modification of this reaction involving lower reaction temperatures ( 140 -- 180 ° C ) and therefore reduced charring increases the yield of the intermediate .   The Wenker synthesis protocol using trans-2-aminocyclooctanol , available from reaction of ammonia with the epoxide of cyclooctene , gives a mixture of cyclooctenimine ( the Wenker aziridine product ) and cyclooctanone ( a competing Hofmann elimination product ) .

negative: Uniflow steam engine The uniflow type of steam engine uses steam that flows in one direction only in each half of the cylinder . Thermal efficiency is increased in the compound and multiple expansion types of steam engine by separating expansion into steps in separate cylinders ; in the uniflow design , thermal efficiency is achieved by having a temperature gradient along the cylinder . Steam always enters at the hot ends of the cylinder and exhausts through ports at the cooler centre . By this means , the relative heating and cooling of the cylinder walls is reduced .

negative: Viggo Jensen Alexander Viggo Jensen ( 22 June 1874 -- 2 November 1930 ) was a Danish weightlifter , shooter , gymnast , and athlete . He was the first Danish Olympic champion , at the 1896 Summer Olympics in Athens .   The first weightlifting event held was the two-handed lift , in a style now known as the clean and jerk . Jensen and Launceston Elliot of Great Britain and Ireland finished the competition tied at 111.5 kilograms , though the judges declared Jensen had performed the lift with better form and would be awarded first place . The British delegation protested , resulting in more attempts being given both lifters to improve their scores . Neither did and therefore Jensen retained first place , but he had injured his shoulder in the extra attempts .   That injury hampered Jensen 's efforts in the one-handed lift , the snatch . He was able to lift only 57.0 kilograms to Elliot 's 71.0 kilograms , taking second place in the event . Jensen competed in the shot put , placing fourth . He was not among the top four in the discus throw , placing sixth .   In the gymnastics competitions , Jensen entered the rope climbing event . He did not finish the climb , placing fourth behind the two Greeks who did reach the top of the 14 metre rope and Fritz Hofmann , who had gotten higher than Jensen . He was ahead of Launceston Elliot in the event .   He also competed in the two rifle events . In the military rifle , Jensen placed sixth with a score of 1,640 points and 30 hits of 40 shots . The free rifle was more successful for him , as he finished third at 1,305 points on 31 hits . His scores for each string of 10 shots were 392 , 423 , 280 , and 210 .


query: Preventing global warming is relatively cheap; business-as-usual will cause accelerating climate damage costs that economists struggle to even estimate.

positive: 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 .

positive: 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 .

positive: 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 .

negative: 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 .

negative: 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 ) .

negative: Runaway climate change Runaway climate change or runaway global warming is hypothesized to follow a tipping point in the climate system , after accumulated climate change initiates a reinforcing positive feedback . This is thought to cause the climate to rapidly change until it reaches a new stable condition . These phrases may be used with reference to concerns about rapid global warming . Some astronomers use the expression runaway greenhouse effect to describe a situation where the climate deviates catastrophically and permanently from the original state -- as happened on Venus .   Although these terms are rarely used in the peer-reviewed climatological literature , that literature does use the similar phrase `` runaway greenhouse effect '' , which refers specifically to climate changes that cause a planetary body 's water to boil off .

negative: Climate change in Europe Climate change in Europe describes the climate change related issues in Europe . This includes the climate politics , contribution in the global warming and the influence of the global warming in Europe .  According to international climate experts global temperature rise should not exceed 2 ° C to prevent the most dangerous consequences of the climate change . It is estimated to demand at least 80-85 % emission reductions in the EU during 2008-2050 with reductions as soon as technically possible . It is estimated that from the now living persons alive are 70 % in the year 2050 . Emission reduction means development and implementation of new energy technology solutions . Some people consider that the technology revolution has already started in Europe since the markets of the renewable technology have annually grown .   European Union climate chief is Connie Hedegaard since 10 February 2010 .

negative: Scientific opinion on climate change The scientific opinion on climate change is the overall judgment among scientists regarding the extent to which global warming is occurring , its causes , and its probable consequences . The scientific consensus is that the Earth 's climate system is unequivocally warming , and that it is extremely likely ( meaning 95 % probability or higher ) that this warming is predominantly caused by humans . It is likely that this mainly arises from increased concentrations of greenhouse gases in the atmosphere , such as from deforestation and the burning of fossil fuels , partially offset by human caused increases in aerosols ; natural changes had little effect .   This scientific opinion is expressed in synthesis reports , by scientific bodies of national or international standing , and by surveys of opinion among climate scientists . Individual scientists , universities , and laboratories contribute to the overall scientific opinion via their peer-reviewed publications , and the areas of collective agreement and relative certainty are summarised in these respected reports and surveys .   National and international science academies and scientific societies have assessed current scientific opinion on global warming . These assessments are generally consistent with the conclusions of the Intergovernmental Panel on Climate Change . The IPCC Fourth Assessment Report stated that :  Warming of the climate system is unequivocal , as evidenced by increases in global average air and ocean temperatures , the widespread melting of snow and ice , and rising global average sea level .  Most of the global warming since the mid-20th century is very likely due to human activities .  Benefits and costs of climate change for -LSB- human -RSB- society will vary widely by location and scale . Some of the effects in temperate and polar regions will be positive and others elsewhere will be negative . Overall , net effects are more likely to be strongly negative with larger or more rapid warming .  The range of published evidence indicates that the net damage costs of climate change are likely to be significant and to increase over time .  The resilience of many ecosystems is likely to be exceeded this century by an unprecedented combination of climate change , associated disturbances ( e.g. flooding , drought , wildfire , insects , ocean acidification ) and other global change drivers ( e.g. land-use change , pollution , fragmentation of natural systems , over-exploitation of resources ) .   Some scientific bodies have recommended specific policies to governments , and science can play a role in informing an effective response to climate change . Policy decisions , however , may require value judgements and so are not included in the scientific opinion .   No scientific body of national or international standing maintains a formal opinion dissenting from any of these main points . The last national or international scientific body to drop dissent was the American Association of Petroleum Geologists , which in 2007 updated its statement to its current non-committal position . Some other organizations , primarily those focusing on geology , also hold non-committal positions .

negative: ExxonMobil climate change controversy The ExxonMobil climate change controversy is the controversy around ExxonMobil 's activities related to climate change , especially their promotion of climate change denial . Since the 1970s , ExxonMobil engaged in research , lobbying , advertising , and grant making , some of which were conducted with the purpose of delaying widespread acceptance and action on global warming .   From the late 1970s and through the 1980s , Exxon funded internal and university collaborations , broadly in line with the developing public scientific approach . After the 1980s , the company was a leader in climate change denial , opposing regulations to curtail global warming . ExxonMobil funded organizations critical of the Kyoto Protocol and seeking to undermine public opinion about the scientific consensus that global warming is caused by the burning of fossil fuels . Exxon helped to found and lead the Global Climate Coalition of businesses opposed to the regulation of greenhouse gas emissions .

negative: Climate governance In political ecology and environmental policy , climate governance is the diplomacy , mechanisms and response measures `` aimed at steering social systems towards preventing , mitigating or adapting to the risks posed by climate change '' . A definitive interpretation is complicated by the wide range of political and social science traditions ( including comparative politics , political economy and multilevel governance ) that are engaged in conceiving and analysing climate governance at different levels and across different arenas . In academia , climate governance has become the concern of geographers , anthropologists , economists and business studies scholars .   In the past two decades a paradox has arisen between rising awareness about the causes and consequences of climate change and an increasing concern that the issues that surround it represent an intractable problem .  Initially , climate change was approached as a global issue , and climate governance sought to address it on the international stage . This took the form of Multilateral Environmental Agreements ( MEAs ) , beginning with the United Nations Framework Convention on Climate Change ( UNFCC ) in 1992 . With the exception of the Kyoto Protocol , international agreements between nations have been largely ineffective in achieving legally binding emissions cuts and with the end of the Kyoto Protocol 's first commitment period in 2012 , starting from 2013 there is no legally binding Global climate regime . This inertia on the international political stage contributed to alternative political narratives that called for more flexible , cost effective and participatory approaches to addressing the multifarious problems of climate change . These narratives relate to the increasing diversity of methods that are being developed and deployed across the field of climate governance .

negative: 4Change 4Change , formerly known as the Climate Change Coalition ( CCC ) , was an Australian political party , which was formed in 2007 with a view to accelerate action by politicians from all parties on global warming and climate change . Its position on working towards addressing climate change , stresses cooperation with big business in order to achieve significant progress on the issue . The party therefore advocates a close working relationship between environmentalists and the business community . The CCC was registered as a political party with the Australian Electoral Commission ( AEC ) on 4 September 2007 and deregistered on 25 March 2010 .

negative: Global warming game A global warming game , also known as a climate game or a climate change game , is a type of serious game . As a serious game , it attempts to simulate and explore real life issues to educate players through an interactive experience . The issues particular to a global warming video game are usually energy efficiency and the implementation of green technology as ways to reduce greenhouse gas emissions and thus counteract global warming . Global warming games also include more traditional board games , video games , as well as other varieties .

negative: Green paradox The green paradox , identified by German economist Hans-Werner Sinn , is the observation that an environmental policy that becomes greener with the passage of time acts like an announced expropriation for the owners of fossil fuel resources , inducing them to accelerate resource extraction and hence to accelerate global warming .

negative: Alan Carlin Alan Carlin ( born 1937 ) , is an American economist specializing in cost-benefit analysis and the economics of global climate change control .

negative: American College & University Presidents' Climate Commitment The American College & University Presidents ' Climate Commitment ( ACUPCC ) is a `` high-visibility effort '' to address global warming ( global climate disruption ) by creating a network of colleges and universities that have committed to neutralize their greenhouse gas emissions and accelerate the research and educational efforts of higher education to equip society to re-stabilize the earth 's climate .   Second Nature is the main supporting organization of the ACUPCC .

negative: Climate change in Germany Climate change in Europe describes the climate change related issues in Europe . This includes the climate politics , contribution in the global warming and the influence of the global warming in Europe .

negative: Drawdown (climate) Climate drawdown is the point at which greenhouse gas concentrations in the atmosphere begin to decline on a year-to-year basis .   Drawdown is a goal for reversing climate change , and eventually reducing global average temperatures .   Project Drawdown is a climate change mitigation project initiated by Paul Hawken and climate activist Amanda Joy Ravenhill . Central to the project is the compilation of a list of the `` 100 most substantive solutions to global warming . '' The list , encompassing only technologically viable , existing solutions , was compiled by a team of over 200 scholars , scientists , policymakers , business leaders and activists ; for each solution the carbon impact through the year 2050 , the total and net cost to society , and the total lifetime savings were measured and modelled .

negative: Surveys of scientists' views on climate change Surveys of scientists ' views on climate change - with a focus on human-caused or anthropogenic global warming ( AGW ) - have been undertaken since the 1990s . A 2016 paper ( which was co-authored by Naomi Oreskes , Peter Doran , William Anderegg , Bart Verheggen , Ed Maibach , J. Stuart Carlton and John Cook , and which was based on a half a dozen independent studies by the authors ) concluded that `` the finding of 97 % consensus -LSB- that humans are causing recent global warming -RSB- in published climate research is robust and consistent with other surveys of climate scientists and peer-reviewed studies . ''

negative: Unstoppable Global Warming: Every 1,500 Years Unstoppable Global Warming : Every 1,500 Years is a book about climate change , written by Siegfried Fred Singer and Dennis T. Avery , which asserts that natural changes , and not CO2 emissions , are the cause of Global Warming . Published by Rowman & Littlefield in 2006 , the book sold well and was reprinted in an updated edition in 2007 .   The title refers to the hypothesis of 1,500-year climate cycles in the Holocene first postulated by Gerard C. Bond , mainly based on petrologic tracers of drift ice in the North Atlantic .

negative: Global Warming Policy Foundation The Global Warming Policy Foundation ( GWPF ) is a think tank in the United Kingdom , whose stated aims are to challenge `` extremely damaging and harmful policies '' envisaged by governments to mitigate anthropogenic global warming .   It promotes climate change denial . In 2014 , when the Charity Commission ruled that the GWPF had breached rules on impartiality , a non-charitable organisation called the `` Global Warming Policy Forum '' or `` GWPF '' was created as a wholly owned subsidiary , to do lobbying that a charity could not .  The GWPF website carries an array of articles `` sceptical '' of scientific findings of anthropogenic global warming and its impacts .

negative: Ross McKitrick Ross McKitrick is a Canadian economist specializing in environmental economics and policy analysis . He is a professor of economics at the University of Guelph , and a senior fellow of the Fraser Institute . He is a member of the academic advisory boards of the John Deutsch Institute , the Global Warming Policy Foundation , and the Cornwall Alliance for the Stewardship of Creation .   He has authored works about climate change issues , including co-authoring the book Taken By Storm : The Troubled Science , Policy and Politics of Global Warming in 2003 . McKitrick produced a series of videos and articles for the Friends of Science in which he argued that there is a `` pause '' in global warming that reveals flaws in current climate change models . The Friends of Science argue that the sun -- not human emissions of GHG -- is the main driver of climate change .

negative: Hurricane Katrina and global warming The tremendous destruction caused by recent Atlantic Ocean tropical cyclones , such as Hurricanes Katrina , Wilma , and Sandy caused a substantial upsurge in interest in the subject of global warming by news media and the wider public , and concerns that global climatic change may have played a significant role in those events . Time Magazine , for example , published an article titled , `` Is Global Warming Fueling Katrina ? '' -- however , the article itself addressed hurricanes in general , rather than Katrina specifically , and was inconclusive .   Shortly after the hurricane , former Boston Globe reporter Ross Gelbspan wrote an op-ed piece for the Globe titled , `` Katrina 's Real Name '' , declaring that the hurricane 's `` real name is global warming . '' Gelbspan went on to assert :  `` Although Katrina began as a relatively small hurricane that glanced off south Florida , it was supercharged with extraordinary intensity by the relatively blistering sea surface temperatures in the Gulf of Mexico . ''  Gelbspan did not single out Katrina from other recent storms in that regard ; in the article he went on to attribute other major weather events over the preceding year to global warming , including a blizzard in Los Angeles , high winds in Scandinavia , wildfires in Spain , and a drought centered in Missouri .   Britain 's then deputy prime minister , John Prescott , has linked Katrina with global warming , and statements made shortly after the hurricane by Germany 's environment minister , Jürgen Trittin , indicate he believes that global warming is responsible for an increase in the frequency of destructive natural events .   Kerry Emanuel had recently published a paper in the journal Nature that found a good correlation between hurricane intensity and sea surface temperatures . Some journalists have claimed Emanuel 's paper concludes that the recent increase in intense Atlantic storms is due to global warming , but Emanuel stated that `` it would be absurd to attribute the Katrina disaster to global warming '' .   The Internet blog RealClimate has written that `` there is no way to prove that Katrina either was , or was not , affected by global warming '' .

negative: Climate change feedback Climate change feedback is important in the understanding of global warming because feedback processes may amplify or diminish the effect of each climate forcing , and so play an important part in determining the climate sensitivity and future climate state . Feedback in general is the process in which changing one quantity changes a second quantity , and the change in the second quantity in turn changes the first . Positive feedback amplifies the change in the first quantity while negative feedback reduces it .   The term `` forcing '' means a change which may `` push '' the climate system in the direction of warming or cooling . An example of a climate forcing is increased atmospheric concentrations of greenhouse gases . By definition , forcings are external to the climate system while feedbacks are internal ; in essence , feedbacks represent the internal processes of the system . Some feedbacks may act in relative isolation to the rest of the climate system ; others may be tightly coupled ; hence it may be difficult to tell just how much a particular process contributes . Forcings , feedbacks and the dynamics of the climate system determine how much and how fast the climate changes . The main positive feedback in global warming is the tendency of warming to increase the amount of water vapor in the atmosphere , which in turn leads to further warming . The main negative feedback comes from the Stefan -- Boltzmann law , the amount of heat radiated from the Earth into space changes with the fourth power of the temperature of Earth 's surface and atmosphere .   Some observed and potential effects of global warming are positive feedbacks , which contribute directly to further global warming . The Intergovernmental Panel on Climate Change 's ( IPCC ) Fourth Assessment Report states that `` Anthropogenic warming could lead to some effects that are abrupt or irreversible , depending upon the rate and magnitude of the climate change . ''

negative: The Real Global Warming Disaster The Real Global Warming Disaster ( Is the Obsession with ` Climate Change ' Turning Out to Be the Most Costly Scientific Blunder in History ? ) is a 2009 book by English journalist and author Christopher Booker in which he asserts that global warming can not be attributed to humans , and then alleges how the scientific opinion on climate change was formulated .   From a standpoint of environmental scepticism , Booker seeks to combine an analysis of the science of global warming with the consequences of political decisions to reduce emissions and claims that , as governments prepare to make radical changes in energy policies , the scientific evidence for global warming is becoming increasingly challenged . He asserts that global warming is not supported by a significant number of climate scientists , and criticises how the UN 's Intergovernmental Panel on Climate Change ( IPCC ) presents evidence and data , in particular citing its reliance on potentially inaccurate global climate models to make temperature projections . Booker concludes , `` it begins to look very possible that the nightmare vision of our planet being doomed '' may be imaginary , and that , if so , `` it will turn out to be one of the most expensive , destructive , and foolish mistakes the human race has ever made '' .   The book 's claims were strongly criticised by science writer Philip Ball , but the book was praised by several columnists . The book opens with an erroneous quotation , which Booker subsequently acknowledged and promised to correct in future editions .   The book was Amazon UK 's fourth bestselling environment book of the decade 2000 -- 10 .

negative: Global warming (disambiguation) Global warming is one of the common names for the current change in Earth 's climate .   Global warming may also refer to :  Global Warming ( Pitbull album ) , a 2011 music album by Pitbull  Global Warming ( Sonny Rollins album ) , a 1998 music album by Sonny Rollins  Global warming game , several games based on the concept   Not to be confused with the Global warming controversy , which refers to the public debate over scientific conclusions on climate change .

negative: Effects of climate change The effects of climate change may refer to :  Effects of global warming , the effects of current climate change  Historical impacts of climate change , during the early evolution and history of humans , prior to current global warming

negative: Global warming hiatus A global warming hiatus , also sometimes referred to as a global warming pause or a global warming slowdown , is a period of relatively little change in globally averaged surface temperatures . In the current episode of global warming many such 15-year periods appear in the surface temperature record , along with robust evidence of the long-term warming trend ; climate is classically averaged over 30-year periods .   Publicity has surrounded claims of a global warming hiatus during the period 1998 -- 2013 . The exceptionally warm El Niño year of 1998 was an outlier from the continuing temperature trend , and so subsequent annual temperatures gave the appearance of a hiatus : by January 2006 , it appeared to some that global warming had stopped or paused . A 2009 study showed that decades without warming were not exceptional , and in 2011 a study showed that if allowances were made for known variability , the rising temperature trend continued unabated . There was increased public interest in 2013 in the run-up to publication of the IPCC Fifth Assessment Report , and despite concerns that a 15-year period was too short to determine a meaningful trend , the IPCC included a section on a hiatus , which it defined as a much smaller increasing linear trend over the 15 years from 1998 to 2012 , than over the 60 years from 1951 to 2012 . Various studies examined possible causes of the short-term slowdown . Even though the overall climate system has continued to accumulate energy due to Earth 's positive energy budget , the available temperature readings at the Earth 's surface indicate slower rates of increase in surface warming than in the prior decade . Since measurements at the top of the atmosphere show that Earth is receiving more energy than it is radiating back into space , the retained energy should be producing warming in the Earth 's climate system .   Research reported in July 2015 on an updated NOAA dataset casts doubt on the existence of a hiatus , and it finds no indication of a slowdown even in earlier years . Scientists working on other datasets welcomed this study , though they have expressed the view that the recent warming trend was less than in previous periods of the same length . Subsequently , a detailed study supports the conclusion that warming is continuing , but it also find there was less warming between 2001 and 2010 than climate models had predicted , and that this slowdown might be attributed to short-term variations in the Pacific decadal oscillation ( PDO ) , which was negative during that period . Another review finds `` no substantive evidence '' of a pause in global warming . A statistical study of global temperature data since 1970 concludes that the term ` hiatus ' or ` pause ' is not justified .   Independent of these discussions about data and measurements for earlier years , 2015 turned out to be much warmer than any of the earlier years , already before El Niño conditions started . The warmth of 2015 largely ended any remaining scientific credibility of claims that the supposed `` hiatus '' since 1998 had any significance for the long-term warming trend . In January 2017 , a study published in the journal Science Advances cast further doubt on the existence of a recent pause , with more evidence that ocean temperatures have been underestimated . An April 2017 study found the data consistent with a steady warming trend globally since the 1970s , with fluctuations within the expected range of short term variability .

negative: Land surface effects on climate Land surface effects on climate are wide-ranging and vary by region . Deforestation and exploitation of natural landscapes play a significant role . Some of these environmental changes are similar to those caused by the effects of global warming .

negative: Climate inertia Climate inertia describes the widespread inherent characteristic of the climate , ecological , and socio-economic systems . Inertia from anthropogenic impacts may be slow to become apparent , or could be irreversible if climate change crosses associated thresholds . Melting ice sheets in Greenland and Antarctica take time to respond to the emissions of fossil fuel carbon in the climate system . The global warming also causes thermal inertia , thermal expansion of the oceans , which contributes to sea level rise . It has been estimated that we are already committed to a sea-level rise of approximately 2.3 meters for each degree of temperature rise within the next 2,000 years .

negative: Cheap meat Cheap meat is a term used to describe relatively inexpensive meat ( e.g. fatty cuts of lamb or mutton ) or to indicate that the consumer price of meat does not include the overall costs of industrial meat production . The term cheap meat is then either related to subsidies , to hidden costs or to non-material costs ( `` moral cost '' ) of meat production . Non-material costs can be related to issues such as animal welfare ( e.g. treatment of animals , over-breeding ) . The term is used by critics of the meat industry .   The meat industry is subsidized with billions of dollars by governments who support their meat industries . The OECD estimates the total `` producer support '' in OECD countries for 2012 as follows : 18bn USD for beef and veal , 7.3 bn USD for pigmeat , 6.5 bn USD for poultry and 1bn USD for sheepmeat ( provisional numbers ) . Hidden costs of meat production can be related to the environmental impact of meat production and to the effect on human health ( such as resistant antibiotics ) .

negative: List of glaciers in Glacier National Park (U.S.) There are at least 35 named glaciers in Glacier National Park ( U.S. ) . In 1850 , the area now comprising the national park had 150 glaciers . There are 25 active glaciers remaining in the park today . Since the ice ages stopped 10,000 years ago , there have been many slight climate shifts causing periods of glacier growth or melt-back . The glaciers are currently being studied to see the effect of global warming It is estimated that if current warming trends continue , there will be no glaciers left in the park by 2030 .

negative: Copenhagen Diagnosis The Copenhagen Diagnosis is a report written by twenty-six climate scientists from eight countries . It was published in 2009 and was a summary of the peer-reviewed literature to date .   The Copenhagen Diagnosis is a follow-up of the previous Intergovernmental Panel on Climate Change 's Working Group 1 Report . The studies summarized , which date back to the cutoff point of the Working Group 1 Report , are those that authors viewed most relevant to the discussions at the 2009 United Nations Climate Change Conference . The Copenhagen Diagnosis served as the midpoint between IPCC -- AR4 and IPCC-AR5 .   In total , the Copenhagen Diagnosis contains eight main sections , which are :   Surging Greenhouse gas emissions  Since 1990 , the combined global emission of carbon dioxide from various origins , such as cement production , deforestation , and fossil fuel burning , has increased 27 % .  Human-induced warming  Studies conducted by Lee and Rind show that only 10 % of global warming over the past century was due to the Sun .  Acceleration of melting ice caps  Glaciers and melting ice caps can contribute to about 8/10ths of a meter to global sea level rise .  Rapid Arctic sea-ice decline  According to simulations run by NCAR Climate System Model version 3 , the Arctic summer is expected to be ice-free by 2040 .  Underestimation of changing sea levels  In contrast to previous IPCC , the rate of sea level rise ( 3.4 mm/yr over the past 15 years ) has increased around 80 % faster than previously predicted .  Damage due to inaction  A region of permafrost , called the Yedoma , stores about 500 Gt of CO2 and , once released due to rising global temperatures , will increase global temperatures even more .  Turning point must come soon  The largest climate science conference , held in 2009 , has stated , `` Temperature rises above 2 ° C will be difficult for contemporary societies to cope with , and are likely to cause major societal and environmental disruptions through the rest of the century and beyond . ''  The Future  By 2100 , global mean air-temperature is projected to warm by 2 ° C -- 7 ° C above pre-industrial levels .

negative: The Economics of Ecosystems and Biodiversity The Economics of Ecosystems and Biodiversity ( TEEB ) is a study led by Pavan Sukhdev . It is an international initiative to draw attention to the global economic benefits of biodiversity . Its objective is to highlight the growing cost of biodiversity loss and ecosystem degradation and to draw together expertise from the fields of science , economics and policy to enable practical actions . TEEB aims to assess , communicate and mainstream the urgency of actions through its five deliverables -- D0 : science and economic foundations , policy costs and costs of inaction , D1 : policy opportunities for national and international policy-makers , D2 : decision support for local administrators , D3 : business risks , opportunities and metrics and D4 : citizen and consumer ownership .   One motive for the study was to establish an objective global standard basis for natural capital accounting . Estimates establish the cost of biodiversity and ecosystem damage expected to cost 18 % of global economic output by 2050 and currently at over US$ 2T ( for the largest 3000 companies according to Trucost ) , with some estimates as high as US$ 6T/year . The World Bank in particular has led recent efforts to include the cost of biodiversity and climate harm in national accounts .   Its sponsors declare TEEB to be a `` major international initiative to draw attention to the global economic benefits of biodiversity , to highlight the growing costs of biodiversity loss and ecosystem degradation , and to draw together expertise from the fields of science , economics and policy to enable practical actions moving forward . '' In October 2010 it released its report `` Mainstreaming the Economics of Nature : a synthesis of the approach , conclusions and recommendations of TEEB '' and launched the Bank of Natural Capital to communicate its findings to the general public .

negative: Robert Balling Robert C. Balling , Jr. is a professor of geography at Arizona State University , and the former director of its Office of Climatology . His research interests include climatology , global climate change , and geographic information systems . Balling has declared himself one of the scientists who oppose the consensus on global warming , arguing in a 2009 book that anthropogenic global warming `` is indeed real , but relatively modest '' , and maintaining that there is a publication bias in the scientific literature .

negative: The Great Global Warming Swindle The Great Global Warming Swindle is a polemical documentary film that suggests that the scientific opinion on climate change is influenced by funding and political factors , and questions whether scientific consensus on global warming exists . The program was formally criticised by Ofcom , the UK broadcasting regulatory agency , which upheld complaints of misrepresentation made by David King .   The film , made by British television producer Martin Durkin , presents scientists , economists , politicians , writers , and others who dispute the scientific consensus regarding anthropogenic global warming . The programme 's publicity materials assert that man-made global warming is `` a lie '' and `` the biggest scam of modern times . '' Its original working title was `` Apocalypse my arse '' , but the title The Great Global Warming Swindle was later adopted as an allusion to the 1980 mockumentary The Great Rock 'n' Roll Swindle about British punk band the Sex Pistols .   The UK 's Channel 4 premiered the documentary on 8 March 2007 . The channel described the film as `` a polemic that drew together the well-documented views of a number of respected scientists to reach the same conclusions . This is a controversial film but we feel that it is important that all sides of the debate are aired . '' According to Hamish Mykura , Channel 4 's head of documentaries , the film was commissioned `` to present the viewpoint of the small minority of scientists who do not believe global warming is caused by anthropogenic production of carbon dioxide . ''   Although the documentary was welcomed by global warming sceptics , it was criticised by scientific organisations and individual scientists ( including one of the scientists interviewed in the film and one whose research was used to support the film 's claims ) . The film 's critics argued that it had misused and fabricated data , relied on out-of-date research , employed misleading arguments , and misrepresented the position of the Intergovernmental Panel on Climate Change . Later broadcasts corrected three errors in the original film .