query: The exception to this ice loss is Antarctic sea ice which has been growing despite the warming Southern Ocean.

positive: Antarctic sea ice Antarctic sea ice is the sea ice of the Southern Ocean . It extends far north in winter and retreats almost to the coastline each summer . Sea ice is frozen seawater that is usually less than a few meters thick . This is in contrast to ice shelves , which are formed by glaciers , float in the sea , and are up to a kilometer thick . There are two subdivisions of sea ice : fast ice , which is attached to land ; and ice floes , which are not .   Sea ice in the Southern Ocean melts from the bottom instead of from the surface like Arctic ice because it is covered in snow . As a result , melt ponds are rarely observed . On average , Antarctic sea ice is younger , thinner , warmer , saltier , and more mobile than Arctic sea ice . Due to its inaccessibility , it is not as well-studied as Arctic ice .

positive: 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 .

negative: Antarctic ice sheet The Antarctic ice sheet is one of the two polar ice caps of the Earth . It covers about 98 % of the Antarctic continent and is the largest single mass of ice on Earth . It covers an area of almost 14 e6km2 and contains 26.5 e6km3 of ice . Approximately 61 percent of all fresh water on the Earth is held in the Antarctic ice sheet , an amount equivalent to about 58 m of sea-level rise . In East Antarctica , the ice sheet rests on a major land mass , but in West Antarctica the bed can extend to more than 2,500 m below sea level . Much of the land in this area would be seabed if the ice sheet were not there .   In contrast to the melting of the Arctic sea ice , sea ice around Antarctica was expanding . The reasons for this are not fully understood , but suggestions include the climatic effects on ocean and atmospheric circulation of the ozone hole , and/or cooler ocean surface temperatures as the warming deep waters melt the ice shelves .

negative: Sea ice Sea ice arises as seawater freezes . Because ice is less dense than water , it floats on the ocean 's surface ( as does fresh water ice , which has an even lower density ) . Sea ice covers about 7 % of the Earth 's surface and about 12 % of the world 's oceans . Much of the world 's sea ice is enclosed within the polar ice packs in the Earth 's polar regions : the Arctic ice pack of the Arctic Ocean and the Antarctic ice pack of the Southern Ocean . Polar packs undergo a significant yearly cycling in surface extent , a natural process upon which depends the Arctic ecology , including the ocean 's ecosystems . Due to the action of winds , currents and temperature fluctuations , sea ice is very dynamic , leading to a wide variety of ice types and features . Sea ice may be contrasted with icebergs , which are chunks of ice shelves or glaciers that calve into the ocean . Depending on location , sea ice expanses may also incorporate icebergs .

negative: Ross Gyre The Ross Gyre is one of the two gyres that exist within the Southern Ocean . The gyre is located in the Ross Sea , and rotates clockwise . The gyre is formed by interactions between the Antarctic Circumpolar Current and the Antarctic Continental Shelf . Sea ice has been noted to persist in the central area of the gyre .   There is some evidence that global warming has resulted in some decrease of the salinity of the waters of the Ross Gyre since the 1950s .

negative: Sea Ice Physics and Ecosystem eXperiment The Sea Ice Physics and Ecosystem eXperiment ( SIPEX ) was an Australian contribution to the International Polar Year ( IPY ) . The expedition studied the sea ice in the Antarctica zone in September and October 2007 , investigating links between the sea ice and the Southern Ocean ecosystems .   Taking part were 45 scientists from 8 different countries , each a specialist on some aspect of the Antarctic sea ice zone . Travelling aboard the research vessel Aurora Australis , the researchers covered East Antarctica between 110 ° E and 130 ° E. Experiments dealt with ice thickness and snow cover , the sympagic fauna and flora and examined the effects of ocean currents and wind .   The extent and distribution of sea ice in the polar regions is a sensitive indicator of global climate change . Global warming has been implicated in significant reductions in the extent of sea ice and this trend is set to continue . An improved understanding of sea ice may lead to improved conservation policies in Antarctica .

negative: 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 .

negative: Weddell Polynya The Weddell Polynya or Weddell Sea Polynya is a polynya or irregular area of open water surrounded by sea ice in the Weddell Sea of the Southern Ocean off Antarctica and near the Maud Rise . The size of New Zealand , it re-occurred each winter between 1974 and 1976 . These were the first three austral winters observed by the Nimbus-5 Electrically Scanning Microwave Radiometer ( ESMR ) . Since 1976 , the polynya has never been seen again . Since the 1970s , the polar Southern Ocean south of the Antarctic Circumpolar Current has freshened and stratified , likely a result of anthropogenic climate change . Such stratification may be responsible for suppressing the return of the Weddell Sea polynya .

negative: Antarctic Cold Reversal The Antarctic Cold Reversal ( ACR ) was an important episode of cooling in the climate history of the Earth during the deglaciation at the close of the last ice age . It illustrates the complexity of the climate changes at the transition from the Pleistocene to the Holocene Epochs .   The Last Glacial Maximum and sea-level minimum occurred c. 21,000 years before present ( BP ) . Antarctic ice cores show gradual warming beginning 3000 years later . At about 14,700 BP , there was a large pulse of meltwater , identified as Meltwater pulse 1A , probably from either the Antarctic ice sheet or the Laurentide ice sheet . Meltwater pulse 1A produced a marine transgression that raised global sea level about 20 meters in two to five centuries and is thought to have influenced the start of the Bølling / Allerød interstadial , the major break with glacial cold in the Northern Hemisphere . Meltwater pulse 1A was followed in Antarctica and the Southern Hemisphere by a renewed cooling , the Antarctic Cold Reversal , in c. 14,500 BP , which lasted for two millennia -- an instance of warming causing cooling . The ACR brought an average cooling of perhaps 3 ° C . The Younger Dryas cooling , in the Northern Hemisphere , began while the Antarctic Cold Reversal was still ongoing , and the ACR ended in the midst of the Younger Dryas .   This pattern of climate decoupling between the Northern and Southern Hemispheres and of `` southern lead , northern lag '' would manifest in subsequent climate events . The cause or causes of this hemispheric decoupling , of the `` lead/lag '' pattern and of the specific mechanisms of the warming and cooling trends are still subjects of study and dispute among climate researchers . The specific dating and intensity of the Antarctic Cold Reversal are also under debate .   The onset of the Antarctic Cold Reversal was followed , after about 800 years , by an Oceanic Cold Reversal in the Southern Ocean .

negative: Ice shelf An ice shelf is a thick floating platform of ice that forms where a glacier or ice sheet flows down to a coastline and onto the ocean surface . Ice shelves are only found in Antarctica , Greenland , Canada and the Russian Arctic . The boundary between the floating ice shelf and the grounded ( resting on bedrock ) ice that feeds it is called the grounding line . The thickness of ice shelves ranges from about 100 to 1000 meters .   In contrast , sea ice is formed on water , is much thinner ( typically less than 3m ) , and forms throughout the Arctic Ocean . It also is found in the Southern Ocean around the continent of Antarctica .   Ice shelves are principally driven by gravity-driven pressure from the grounded ice . That flow continually moves ice from the grounding line to the seaward front of the shelf . The primary mechanism of mass loss from ice shelves was thought to have been iceberg calving , in which a chunk of ice breaks off from the seaward front of the shelf . A study by NASA and university researchers - published in the June 14 , 2013 issue of Science - found however that ocean waters melting the undersides of Antarctic ice shelves are responsible for most of the continent 's ice shelf mass loss .   Typically , a shelf front will extend forward for years or decades between major calving events . Snow accumulation on the upper surface and melting from the lower surface are also important to the mass balance of an ice shelf . Ice may also accrete onto the underside of the shelf .   The density contrast between glacial ice , which is denser than normal ice , and liquid water means that only about 1/9 of the floating ice is above the ocean surface . The world 's largest ice shelves are the Ross Ice Shelf and the Filchner-Ronne Ice Shelf in Antarctica .   The term captured ice shelf has been used for the ice over a subglacial lake , such as Lake Vostok .

negative: Geography of Antarctica The geography of Antarctica is dominated by its south polar location and , thus , by ice . The Antarctic continent , located in the Earth 's southern hemisphere , is centered asymmetrically around the South Pole and largely south of the Antarctic Circle . It is washed by the Southern ( or Antarctic ) Ocean or , depending on definition , the southern Pacific , Atlantic , and Indian Oceans . It has an area of more than 14 million km ² .   Some 98 % of Antarctica is covered by the Antarctic ice sheet , the world 's largest ice sheet and also its largest reservoir of fresh water . Averaging at least 1.6 km thick , the ice is so massive that it has depressed the continental bedrock in some areas more than 2.5 km below sea level ; subglacial lakes of liquid water also occur ( e.g. , Lake Vostok ) . Ice shelves and rises populate the ice sheet on the periphery .

negative: Arctic ice pack The Arctic ice pack is the ice cover of the Arctic Ocean and its vicinity . The Arctic ice pack undergoes a regular seasonal cycle in which ice melts in spring and summer , reaches a minimum around mid-September , then increases during fall and winter . Summer ice cover in the Arctic is about 50 % of winter cover . Some of the ice survives from one year to the next . Currently 28 % of Arctic basin sea ice is multi-year ice , thicker than seasonal ice : up to 3 - thick over large areas , with ridges up to 20 m thick . As well as the regular seasonal cycle there has been an underlying trend of declining sea ice in the Arctic in recent decades .

negative: West Antarctica West Antarctica , or Lesser Antarctica , one of the two major regions of Antarctica , is the part of that continent that lies within the Western Hemisphere , and includes the Antarctic Peninsula . It is separated from East Antarctica by the Transantarctic Mountains and is covered by the West Antarctic Ice Sheet . It lies between the Ross Sea ( partly covered by the Ross Ice Shelf ) , and the Weddell Sea ( largely covered by the Filchner-Ronne Ice Shelf ) . It may be considered a giant peninsula stretching from the South Pole towards the tip of South America .   West Antarctica is largely covered by the Antarctic ice sheet , but there have been signs that climate change is having some effect and that this ice sheet may have started to shrink slightly . The coasts of the Antarctic Peninsula are the only parts of West Antarctica that become ( in summer ) ice-free . These constitute the Marielandia Antarctic tundra and have the warmest climate in Antarctica . The rocks are clad in mosses and lichens that can cope with the intense cold of winter and the short growing-season .

negative: Drift ice Drift ice is any sea ice other than fast ice , the latter being attached ( `` fastened '' ) to the shoreline or other fixed objects ( shoals , grounded icebergs , etc. ) . Drift ice is carried along by winds and sea currents , hence its name . When drift ice is driven together into a large single mass ( > 70 % coverage ) , it is called pack ice . Wind and currents can pile up that ice to form ridges up to several metres in height . These represent a challenge for icebreakers and offshore structures operating in cold oceans and seas .   Drift ice consists of floes , individual pieces of sea ice 20 m or more across . There are names for various floe sizes : small -- 20 m to 100 m ; medium -- 100 m to 500 m ; big -- 500 m to 2000 m ; vast -- 2 km to 10 km ; and giant -- more than 10 km .   Seasonal ice drift in the Sea of Okhotsk by the northern coast of Hokkaidō , Japan has become a tourist attraction of this area with harsh climate , and is one of the 100 Soundscapes of Japan . The Sea of Okhotsk is the southernmost area in the Northern hemisphere where drift ice may be observed .   Drift ice affects :  Security of navigation  Climatic impact ( see Polar ice packs )  Geological impact  Biosphere influence ( see Ecology of sea ice )   The two major ice packs are the Arctic ice pack and the Antarctic ice pack . The most important areas of pack ice are the polar ice packs formed from seawater in the Earth 's polar regions : the Arctic ice pack of the Arctic Ocean and the Antarctic ice pack of the Southern Ocean . Polar packs significantly change their size during seasonal changes of the year . Because of vast amounts of water added to or removed from the oceans and atmosphere , the behavior of polar ice packs has a significant impact on global changes in climate .

negative: Polar seas Polar seas is a collective term for the Arctic Ocean ( about 4-5 percent of Earth 's oceans ) and the southern part of the Southern Ocean ( south of Antarctic Convergence , about 10 percent of Earth 's oceans ) . In the coldest years , sea ice can cover around 13 percent of the Earth 's total surface at its maximum , but out of phase in the two hemispheres . The polar seas contain a huge biome with many organisms .   Among the species that inhabit various polar seas and surrounding land areas are polar bear , penguin , reindeer ( caribou ) , muskox , wolverine , ermine , lemming , Arctic hare , Arctic ground squirrel , whale , harp seal , and walrus . These species have unique adaptations to the extreme conditions . Many might be endangered if they can not adapt to changing conditions . Contrary to popular opinion , the World Wildlife Fund studies for polar bears show that this species has prospered since 1950 , attaining five times the numbers found in 1950 . In general , Arctic ecosystems are relatively fragile and slow to recover from serious damage .

negative: Weddell Sea The Weddell Sea is part of the Southern Ocean and contains the Weddell Gyre . Its land boundaries are defined by the bay formed from the coasts of Coats Land and the Antarctic Peninsula . The easternmost point is Cape Norvegia at Princess Martha Coast , Queen Maud Land . To the east of Cape Norvegia is the King Haakon VII Sea . Much of the southern part of the sea is covered by a permanent , massive ice shelf field , the Filchner-Ronne Ice Shelf ( not pack ice ) . The sea is contained within the two overlapping Antarctic territorial claims of Argentina , ( Argentine Antarctica ) and Britain ( British Antarctic Territory ) , and also resides partially within the territorial claim of Chile ( Antarctic Chilean Territory ) . At its widest the sea is around 2,000 km across , and its area is around 2.8 e6km2 .   Various ice shelves , including the Filchner-Ronne Ice Shelf , fringe the Weddell sea . Some of the ice shelves on the east side of the Antarctic Peninsula , which formerly covered roughly 3900 sqmi of the Weddell Sea , had completely disappeared by 2002 ; see . Whilst a dramatic event , the area that disappeared was far smaller than the total area of ice shelf that remains .   The Weddell Sea has been deemed by scientists to have the clearest water of any sea . Dutch researchers from the German Alfred Wegener Institute , on finding a Secchi disc visible at a depth of 262 ft on 13 October 1986 , ascertained that the clarity corresponded to that of distilled water .   In his 1950 book The White Continent , historian Thomas R. Henry writes :   He continues for an entire chapter , relating myths of the green-haired merman sighted in the sea 's icy waters , the inability of crews to navigate a path to the coast until 1949 , and treacherous `` flash freezes '' that left ships , such as Ernest Shackleton 's Endurance , at the mercy of the ice floes .

negative: Fragilariopsis kerguelensis Fragilariopsis kerguelensis , is a pennate diatom native to the Southern Ocean . It has been characterized as `` the most abundant diatom in the Antarctic Seas '' .

negative: 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 .

negative: Southern Ocean The Southern Ocean , also known as the Antarctic Ocean or the Austral Ocean , comprises the southernmost waters of the World Ocean , generally taken to be south of 60 ° S latitude and encircling Antarctica . As such , it is regarded as the fourth-largest of the five principal oceanic divisions : smaller than the Pacific , Atlantic , and Indian Oceans but larger than the Arctic Ocean . This ocean zone is where cold , northward flowing waters from the Antarctic mix with warmer subantarctic waters .   By way of his voyages in the 1770s , Captain James Cook proved that waters encompassed the southern latitudes of the globe . Since then , geographers have disagreed on the Southern Ocean 's northern boundary or even existence , considering the waters part of the Pacific , Atlantic , and Indian Oceans , instead . This remains the current official policy of the International Hydrographic Organization ( IHO ) , since a 2000 revision of its definitions including the Southern Ocean as the waters south of the 60th parallel has not yet been adopted . Others regard the seasonally-fluctuating Antarctic Convergence as the natural boundary .

negative: Amundsen Sea The Amundsen Sea , an arm of the Southern Ocean off Marie Byrd Land in western Antarctica , lies between Cape Flying Fish ( the northwestern tip of Thurston Island ) to the east and Cape Dart on Siple Island to the west . Cape Flying Fish marks the boundary between the Amundsen Sea and the Bellingshausen Sea . West of Cape Dart there is no named marginal sea of the Southern Ocean between the Amundsen and Ross Seas . The Norwegian expedition of 1928 -- 1929 under Captain Nils Larsen named the body of water for the Norwegian polar explorer Roald Amundsen while exploring this area in February 1929 .   The sea is mostly ice-covered , and the Thwaites Ice Tongue protrudes into it . The ice sheet which drains into the Amundsen Sea averages about 3 km in thickness ; roughly the size of the state of Texas , this area is known as the Amundsen Sea Embayment ( ASE ) ; it forms one of the three major ice-drainage basins of the West Antarctic Ice Sheet .

negative: Antarctic continental shelf The Antarctic continental shelf is a geological feature that underlies the Southern Ocean , surrounding the continent of Antarctica . The shelf is generally narrow and unusually deep , its edge lying at depths averaging 500 meters ( the global mean is around 100 meters ) , with troughs extending as far as 2000 meters deep . It is home to a thriving ecosystem of penguins and cold-water fish and crustaceans .   Several countries have issued proclamations claiming ownership over parts of the shelf , including Chile ( since 1947 ) , Australia ( since 1953 ) , France , and Argentina .

negative: Antarctic Convergence The Antarctic Convergence is a curve continuously encircling Antarctica , varying in latitude seasonally , where cold , northward-flowing Antarctic waters meet the relatively warmer waters of the subantarctic . Antarctic waters predominantly sink beneath subantarctic waters , while associated zones of mixing and upwelling create a zone very high in marine productivity , especially for Antarctic krill . This line , like the Arctic tree line , is a natural boundary rather than an artificial one like a line of latitude . It not only separates two hydrological regions , but also separates areas of distinctive marine life associations and of different climates . There is no Arctic equivalent , due to the amount of land surrounding the northern polar region .

negative: Adaptation to global warming in Australia

negative: Karoo Ice Age The Karoo Ice Age from 360 -- 260 million years ago ( Mya ) was the second major ice age of the Phanerozoic Eon . It is named after the tillite ( Dwyka Group ) found in the Karoo region of South Africa ( and adjacent areas ) , where evidence for this ice age was first clearly identified in the 19th century .   The tectonic assembly of the continents of Euramerica ( later with the Uralian orogeny , into Laurasia ) and Gondwana into Pangaea , in the Hercynian-Alleghany Orogeny , made a major continental land mass within the Antarctic region , and the closure of the Rheic Ocean and Iapetus Ocean saw disruption of warm-water currents in the Panthalassa Ocean and Paleotethys Sea , which led to progressive cooling of summers , and the snowfields accumulating in winters , causing mountainous alpine glaciers to grow , and then spread out of highland areas , making continental glaciers which spread to cover much of Gondwana .   At least two major periods of glaciation have been discovered :  The first glacial period was associated with the Mississippian subperiod ( 359.2 -- 318.1 Mya ) : ice sheets expanded from a core in southern Africa and South America .  The second glacial period was associated with the Pennsylvanian subperiod ( 318.1 -- 299 Mya ) ; ice sheets expanded from a core in Australia and India .   The extent of ancient glaciations in Antarctica is not well known , because the present ice sheet hides the evidence .

negative: Sea ice growth processes Sea ice is a complex composite composed primarily of pure ice in various states of crystallization along with air bubbles and included pockets of brine . Understanding its growth processes is important both for climate scientists for use in simulations as well remote sensing specialists since the composition and microstructural properties of the ice ultimately affect how it interacts with electromagnetic radiation .   Sea ice growth models for predicting the ice distribution and extent are also valuable for shipping concerns . An ice growth model can be combined with remote sensing measurements in an assimilation model as a means of generating more accurate ice charts .

negative: Cook Ice Shelf Cook Ice Shelf is an ice shelf about 55 mi wide , occupying a deep recession of the coastline between Cape Freshfield and Cape Hudson , to the east of Deakin Bay . This indentation was called Cook Bay by the Australasian Antarctic Expedition , 1911 -- 14 , under Douglas Mawson , who named it for Joseph Cook , Prime Minister of Australia in 1914 . The generic term has been amended , as the bay is permanently filled by an ice shelf .   Scientists studying the effects of global warming have proposed that sea water encroachment in the area could destabilize a significant portion of the East Antarctic Ice Sheet .

negative: ANDRILL ANDRILL ( ANtarctic DRILLing Project ) is a scientific drilling project in Antarctica gathering information about past periods of global warming and cooling . The project involves scientists from Germany , Italy , New Zealand , and the United States . At two sites in 2006 and 2007 , ANDRILL team members drilled through ice , seawater , sediment and rock to a depth over more than 1,200 m and recovered a virtually continuous core record from the present to nearly 20 million years ago . The project is based at McMurdo Station in Antarctica .   In studying the cores , ANDRILL scientists from various disciplines are gathering detailed information about past periods of global warming and cooling . A major goal of the project is to significantly improve the understanding of Antarctica 's impact on the world 's oceans currents and the atmosphere by reconstructing the behavior of Antarctic sea-ice , ice-shelves , glaciers and sea currents over tens of millions of years . Initial results imply rapid changes and dramatically different climates at various times on the southernmost continent.Quirin Scheirmeier , `` Sediment cores reveal Antarctica 's warmer past , '' Nature News , April 24 , 2008 .   The $ 30 million project has achieved its operational goal of retrieving a continuous core record of the last 17 million years , filling crucial gaps left by previous drilling projects . Making use of knowledge gained through prior Antarctic drilling projects , ANDRILL employed novel techniques to reach record depths at its two drilling sites . Among the innovations deployed were a hot-water drilling system that allowed for easier ice-boring and a flexible drill pipe that could accommodate tidal oscillations and strong currents .   On December 16 , 2006 , ANDRILL broke the previous record of 999.1 m set in 2000 by the Ocean Drilling Program 's drill ship , the Joides Resolution . The Antarctic-record 1285 m of core ANDRILL went on to recover represents geologic time to about 13 million years ago . In 2007 , drilling at the Southern McMurdo Sound , ANDRILL scientists recovered another 1138 meters ( 3733.6 ft ) of core . One goal in 2006 was to look at a period of around 3 to 5 million years ago in the Pliocene , which scientists know to be warmer . The team 's sedimentologists identified more than 60 cycles in which ice sheets or glaciers advanced and retreated across McMurdo Sound .

negative: Antarctic krill Antarctic krill ( Euphausia superba ) is a species of krill found in the Antarctic waters of the Southern Ocean . It is a small , swimming crustacean that lives in large schools , called swarms , sometimes reaching densities of 10,000 -- 30,000 individual animals per cubic metre . It feeds directly on minute phytoplankton , thereby using the primary production energy that the phytoplankton originally derived from the sun in order to sustain their pelagic ( open ocean ) life cycle . It grows to a length of 6 cm , weighs up to 2 g , and can live for up to six years . It is a key species in the Antarctic ecosystem and is , in terms of biomass , probably the most abundant animal species on the planet ( approximately 500 million tonnes , corresponding to 300 to 400 trillion individuals ) .

negative: Ice-albedo feedback Ice-albedo feedback ( or snow-albedo feedback ) is a positive feedback climate process where a change in the area of snow-covered land , ice caps , glaciers or sea ice alters the albedo . This change in albedo acts to reinforce the initial alteration in ice area . Cooling tends to increase ice cover and hence the albedo , reducing the amount of solar energy absorbed and leading to more cooling . Conversely , warming tends to decrease ice cover and hence the albedo , increasing the amount of solar energy absorbed , leading to more warming .   The effect also applies on the small scale to snow-covered surfaces . A small amount of snow melt exposes darker ground which absorbs more radiation , leading to more snowmelt .   The effect has mostly been discussed in terms of the recent trend of declining Arctic sea ice .   Internal feedback processes may also potentially occur , as land ice melts and causes eustatic sea level rise , and also potentially induces earthquakes as a result of isostatic rebound , which further acts to disrupt glaciers , ice shelves , etc. .

negative: Human impact on marine life Human activities affect marine life and marine habitats through overfishing, habitat loss, the introduction of invasive species, ocean pollution, ocean acidification and ocean warming. These impact marine ecosystems and food webs and may result in consequences as yet unrecognised for the biodiversity and continuation of marine life forms.According to the IPCC (2019), since 1950 "many marine species across various groups have undergone shifts in geographical range and seasonal activities in response to ocean warming, sea ice change and biogeochemical changes, such as oxygen loss, to their habitats."It has been estimated only 13% of the ocean area remains as wilderness, mostly in open ocean areas rather than along the coast.

negative: Sympagic ecology A sympagic environment is one where water exists mostly as a solid , ice , such as a polar ice cap or glacier . Solid sea ice is permeated with channels filled with salty brine . These briny channels and the sea ice itself have its ecology , referred to as `` sympagic ecology '' .   Residents of temperate or tropical climates often assume , mistakenly , that ice and snow are devoid of life . In fact , a number of varieties of algae such as diatoms engage in photosynthesis in arctic and alpine regions of Earth . Other energy sources include Aeolian dust and pollen swept in from other regions . These ecosystems also include bacteria and fungi , as well as animals like flatworms and crustaceans . A number of sympagic worm species are commonly called ice worms .   Additionally , the ocean has abundant plankton , and prolific algal blooms occur in the polar regions each summer as well as in high mountain lakes , bringing nutrients to those parts of the ice in contact with the water .   In the spring , krill can scrape off the green lawn of ice algae from the underside of the pack ice .

negative: Sea ice thickness Sea ice thickness spatial extent , and open water within ice packs can vary rapidly in response to weather and climate . Sea ice concentration are measured by satellites , with the Special Sensor Microwave Imager / Sounder ( SSMIS ) , and the European Space Agency 's Cryosat-2 satellite to map the thickness and shape of the Earth 's polar ice cover . The sea ice volume is calculated with the Pan-Arctic Ice Ocean Modeling and Assimilation System ( PIOMAS ) , which blends satellite-observed data , such as sea ice concentrations into model calculations to estimate sea ice thickness and volume . Sea ice thickness determines a number of important fluxes such as heat flux between the air and ocean surface -- see below -- as well as salt and fresh water fluxes between the ocean since saline water ejects much of its salt content when frozen -- see sea ice growth processes . It is also important for navigators on icebreakers since there is an upper limit to the thickness of ice any ship can sail through .

negative: Duncan Wingham Duncan John Wingham ( born 12 October 1957 ) is a British physicist who is Professor of Climate Physics at University College London , and was the first Director of the Centre for Polar Observation & Modelling . He is chief executive of the Natural Environment Research Council and Principal Scientist for the CryoSat Satellite Mission .   In the 1990s , Wingham was involved in a four-year satellite study of the Antarctic ice sheet . His conclusion then , and from later research , is that the Antarctic has contributed little to observed rising sea levels in the 20th century . However , he has also stated that `` it is possible that the consequences of global warming on sea level rise have been underestimated ... Other sources of rise must be underestimated . In particular it is possible that the effect of global warming on thermal expansion -LSB- on the oceans -RSB- is larger than we thought '' .   In a 2005 interview Wingham stated '' -LSB- t -RSB- he Antarctic is to some extent insulated from global warming because to its north are zonal flows in the atmosphere and ocean , unimpeded by other landmasses ... I am not denying global warming . ''

negative: Antarctic oscillation The Antarctic oscillation ( AAO , to distinguish it from the Arctic oscillation or AO ) is a low-frequency mode of atmospheric variability of the southern hemisphere . It is also known as the Southern Annular Mode ( SAM ) . It is defined as a belt of westerly winds or low pressure surrounding Antarctica which moves north or south as its mode of variability . In its positive phase , the westerly wind belt contracts towards Antarctica , while its negative phase involves this belt moving towards the Equator .   In 2014 , Dr Nerilie Abram used a network of temperature-sensitive ice core and tree growth records to reconstruct a 1000-year history of the Southern Annular Mode . This work suggests that the Southern Annular Mode is currently in its most extreme positive phase over at least the last 1000 years , and that recent positive trends in the SAM are attributed to increasing greenhouse gas levels and later stratospheric ozone depletion .


query: Extreme high temperatures were seen from India — where the city of Phalodi recorded temperatures of 51 degrees Celsius (123.8 Fahrenheit) in May, a new national record — to Iran, where a temperature of 53 degrees Celsius (127.4 F) was recorded in Delhoran on July 22.

positive: Phalodi Phalodi is a city and a municipality in Jodhpur district in the Indian state of Rajasthan . It is the headquarters for Phalodi tehsil . Phalodi is also called the `` salt city '' due to the concentration of a large number of salt industries located in the area . Phalodi is in the buffer zone of Thar Desert and often subject to extreme temperature conditions due to arid climate . It holds the record for the highest verified temperature recorded in India at 52 degrees Celsius ( 123.8 ° F ) on 20 May 2016 .

positive: 2019 heat wave in India and Pakistan From mid-May to mid-June 2019, India and Pakistan had a severe heat wave. It was one of the hottest and longest heat waves since the two countries began recording weather reports. The highest temperatures occurred in Churu, Rajasthan, reaching up to 50.8 °C (123.4 °F), a near record high in India, missing the record of 51.0 °C (123.8 °F) set in 2016 by a fraction of a degree. As of 12 June 2019, 32 days are classified as parts of the heatwave, making it the second longest ever recorded.As a result of hot temperatures and inadequate preparation, more than 184 people died in the state of Bihar, with many more deaths reported in other parts of the country. In Pakistan, five infants died after extreme heat exposure.The heat wave coincided with extreme droughts and water shortages across India and Pakistan. In mid-June, reservoirs that previously supplied Chennai ran dry, depriving millions. The water crisis was exacerbated by high temperatures and lack of preparation, causing protests and fights that sometimes led to killing and stabbing.

positive: Abadan, Iran Abadan ( آبادان Ābādān ) is a city in and the capital of Abadan County , Khuzestan Province which is located in central west of Iran . It lies on Abadan Island ( 68 km long , 3 -- 19 km or 2 -- 12 miles wide ) , the island is bounded in the west by the Arvand waterway and to the east by the Bahmanshir outlet of the Karun River ( the Shatt al-Arab ) , 53 km from the Persian Gulf , near the Iraqi-Iran border . '' '

positive: 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.

negative: World's tallest thermometer The World 's Tallest Thermometer is a landmark located in Baker , California , USA . It is an electric sign that commemorates the record 134 degrees Fahrenheit ( 57 degrees Celsius ) recorded in nearby Death Valley on July 10 , 1913 .   The sign weighs 76812 lb and is held together by 125 cuyd of concrete . It stands 134 ft tall and is capable of displaying a maximum temperature of 134 F , both of which are a reference to the temperature record .

negative: 1911 Eastern North America heat wave The 1911 Eastern North America heat wave was an 11-day heat wave in New York City and other Eastern cities that killed 380 people starting on July 4 , 1911 . In Nashua , New Hampshire , the temperature peaked at 106 degrees Fahrenheit ( 41 C ) . In New York City , 146 people and 600 horses died .   In Boston , the temperature rose to 104 ° ( 40 ° C ) on July 4 , an all-time record high that still stands today .

negative: List of extreme weather records in Pakistan The weather extremes in Pakistan include high and low temperatures , Heaviest rainfall and flooding . The highest temperature ever recorded in Pakistan is 54 ° C which was recorded in Turbat , Balochistan 30 May 2017 It was not only the hottest temperature ever recorded in Pakistan but also the hottest reliably measured temperature ever recorded on the continent of Asia . and the fourth-highest temperature ever recorded on earth . The second-highest temperature ever recorded in Pakistan is 53 C which was recorded in Larkana , Sindh on 26 May 2010 . It is hottest city in Pakistan , as well as the second hottest city in the world , but it is second-hottest place in Pakistan and fifth-hottest place of world . It is fifth-highest temperature ever recorded on Earth . The highest rainfall of 620 mm was recorded in Islamabad during 24 hours on 23 July 2001 . The record-breaking rain fell in just 10 hours .

negative: 2017 Pakistan heat wave In April 2017 , a severe heat wave with temperatures as high as 51 ° C ( 124 ° F ) hit Pakistan , especially its southern parts . This heat wave broke the old temperature records of many cities in the country for the month of April . Larkana , a city in the southern province of Sindh , experienced the highest maximum temperature of 51.0 ° C on 20 April , breaking the previous day 's record of 50 ° C.

negative: 2002 India heat wave More than 1,030 people were killed in the 2002 heatwave in south India . Most of the dead were poor and elderly and a majority of deaths occurred in the southern state of Andhra Pradesh . In districts that were impacted most , the heat was so severe that ponds and rivers evaporated and in those same districts birds had fallen from the sky and animals were collapsing from the intense heat . It is said by officials to be the worst heat wave in four years . The relief commissioner of Andhra Pradesh , Rosaiah , said that the maximum number of 172 deaths related to heat took place in the East Godavari district . There were also 166 deaths in Prakasam and 144 deaths in West Godavari . Unusually high temperatures were detected across India during April of the year 2002 . In addition , this heat wave over northern zones of India lasted from the middle of April to the third week in May , thus , causing these fatalities . On May 10 the highest temperature recorded in the region of Gannavaram ( Vijayawada ) was 49 degrees Celsius ( 120.2 degrees Fahrenheit ) . According to the BBC News , `` Heatwaves are defined as periods of abnormally high temperatures and usually occur between March and June in India . May is the country 's hottest month , with an average maximum temperature of 41C ( 104F ) in Delhi . Longer , more severe heatwaves are becoming increasingly frequent globally . Intense heat can cause cramps , exhaustion and heat stroke . Thousands of people have died across India during heatwaves in 2002 and 2003 . '' The heatwaves also affected the northern states of Punjab , Haryana , Orissa and 100 people suffered from heat-related sickness .  2010 Indian heatwave

negative: 1990 United Kingdom heat wave The 1990 heat wave in the United Kingdom was a particularly severe heat event with temperatures hitting record highs of 37.1 C on 3 August . The temperature was recorded at Cheltenham , Gloucestershire , and was a full degree Celsius above the previous record , set in 1911 . However , this record was subsequently broken in the 2003 heatwave .

negative: 2007 Asian heat wave The 2007 Asian heat wave affected the South Asian countries of India , Pakistan , Bangladesh , and Nepal , as well as Russia , Japan and the People 's Republic of China . The heat wave ran during the months of May and June , which continued to September in Japan .

negative: Gotvand Gotvand is a city in and the capital of Gotvand County , Khuzestan Province , Iran . At the 2006 census , its population was 21,428 , in 4,422 families . Gotvand holds share-record for highest temperature recorded in Iran with 53,0 ° C ( July 17 , 2014 ) , tying the record set at Dehloran in July 2011 . The Lower and Upper Gotvand Dams are located northeast of the city on the Karun River .

negative: 2013 extreme weather events The 2013 extreme weather events included several all-time temperature records in Northern and Southern Hemisphere . The February extent of snow cover in Eurasia and North America was above average , while the extent of Arctic ice in the same month was 4,5 % below the 1981 -- 2010 average . The Northern Hemisphere weather extremes have been linked to the melting of Arctic sea ice , which alters atmospheric circulation in a way that leads to more snow and ice .   By January 11 , 233 weather-related deaths were reported in India . Elsewhere , particularly in Russia , the Czech Republic and the United Kingdom , low temperatures affected wildlife , delaying bird breeding and disrupting the bird migration . On January 10 Bangladesh faced the lowest temperature since country 's independence , at 3.0 ° C in Saidpur . While Finland and most of Northern European countries got the record high , and even the highest temperatures at Europe during May and June , Western - and Middle Europe faced much cooler weather and even their wettest May and June ever . During summer prolonged heat waves in the Northern Hemisphere set new record high temperatures .   On March 24 , 2014 , the secretary-general of the World Meteorological Organization Michel Jarraud announced that `` many of the extreme events of 2013 were consistent with what we would expect as a result of human-induced climate change '' .

negative: 2009 Pacific Northwest heat wave The 2009 Pacific Northwest heat wave was a heat wave that affected the Pacific Northwest region of the United States and Canada in late July 2009 , particularly areas west of the Cascade Mountains in British Columbia , Oregon and Washington . The heat wave set many new heat records across the area , and broke the previous all-time record high temperature in Seattle by three Fahrenheit degrees ( 1.7 Celsius degrees ) . Because the temperatures reached in the heat wave are rare in the Pacific Northwest , few residents own air conditioners .

negative: Qaisumah Qaisumah or Al Qaysumah is a village belonging to the city of Hafar Al-Batin , in Eastern Province ( also known as Ash Sharqiyah ) , Saudi Arabia . It is located at around .   The weather here is extreme with rainfall ranging between 5 -- 10 mm . Summer temperatures ranges from 45-51 degrees Celsius . Whereas the winter temperatures may go below freezing point ( between -1 to 6 degrees Celsius ) , with the lowest temperature recorded is -6 degree Celsius . The town has 100 % Islam religion with no minorities in and around the town . -LSB- Citation needed -RSB-

negative: Degree of frost A degree of frost is a non-standard unit of measure for air temperature meaning degrees below melting point ( also known as `` freezing point '' ) of water ( 0 degrees Celsius or 32 degrees Fahrenheit ) . `` Degree '' in this case can refer to degree Celsius or Fahrenheit .   When based on Celsius , 0 degrees of frost is the same as 0 ° C , and any other value is simply the negative of the Celsius temperature . When based on Fahrenheit , the conversion is a bit more complicated , as 0 degrees of frost is equal to 32 ° F. Conversion formulas :  T -LSB- degrees of frost -RSB- = 32 ° F - T -LSB- ° F -RSB-  T -LSB- ° F -RSB- = 32 ° F - T ( degrees of frost )   The term `` degrees of frost '' was widely used in accounts of the Heroic Age of Antarctic Exploration in the early 20th century . The term appears frequently in Ernest Shackleton 's books South and Heart of the Antarctic , Apsley Cherry-Garrard 's account of his Antarctic adventures in The Worst Journey in the World ( wherein he recorded 109.5 ( Fahrenheit ) degrees of frost , -- 77.5 ° F or -- 60.8 ° C ) , as well as Admiral Richard E. Byrd 's book Alone .

negative: 0° 0 ° or 0 degrees may refer to :  prime meridian , longitude  equator , latitude  freezing point of water ( Celsius )  absolute zero , the lower limit of the thermodynamic temperature scale  0 ° Fahrenheit , approximately -17.78 ° Celsius

negative: Self-cleaning oven A self-cleaning oven is an oven which uses high temperature ( approximately 500 degrees Celsius or 900 degrees Fahrenheit ) to burn off leftovers from baking , without the use of any chemical agents .

negative: List of extreme temperatures in Germany The following table lists the highest and lowest temperatures recorded in each state in Germany , in both Fahrenheit and Celsius .

negative: List of extreme temperatures in Italy The following table lists the highest and lowest temperatures recorded in each region in Italy , in both Fahrenheit and Celsius .   * Also on earlier date or dates in that region or city .

negative: 2013 Southwestern United States heat wave The 2013 Southwestern United States heat wave occurred in late June to early July 2013 , lasting from around four days to a week locally . Daily highs were up to 15 ° C ( 26 ° F ) above average , with relative humidity below 15 % . Many locations experienced temperatures over 45 ° C ( 113 ° F ) . 46 monthly record high temperatures were reached or broken , and 21 records for the highest overnight temperatures were reached or broken .

negative: U.S. state temperature extremes The following table lists the highest and lowest temperatures recorded in each state in the United States , in both Fahrenheit and Celsius during the past two centuries .   * Also on earlier date or dates in that state

negative: U.S. state and territory temperature extremes The following table lists the highest and lowest temperatures recorded in the 50 U.S. states, the District of Columbia, and the 5 inhabited U.S. territories during the past two centuries, in both Fahrenheit and Celsius. If two dates have the same temperature record (e.g. record low of 40°F in 1911 in Aibonito and 1966 in San Sebastian in Puerto Rico), only the most recent date is shown.

negative: 2015 Pakistan heat wave A severe heat wave with temperatures as high as 49 C struck southern Pakistan in June 2015 . It caused the deaths of about 2,000 people from dehydration and heat stroke , mostly in Sindh province and its capital city , Karachi . The heat wave also claimed the lives of zoo animals and countless agricultural livestock . The event followed a separate heat wave in neighboring India that killed 2,500 people in May 2015 .

negative: Stratopause The stratopause ( formerly Mesopeak ) is the level of the atmosphere which is the boundary between two layers : the stratosphere and the mesosphere . In the stratosphere the temperature increases with altitude , and the stratopause is the region where a maximum in the temperature occurs .  This atmospheric feature is not only associated with Earth : it occurs on any other planet or moon that has an atmosphere as well .   On Earth , the stratopause is 50 to high above the Earth 's surface . The atmospheric pressure is around 1/1000 of the pressure at sea level . The temperature in the stratopause is -15 degrees Celsius ( 5 degrees Fahrenheit ) .

negative: Climate of Nawabshah The climate of Nawabshah is hot to extremely hot during the summers and cold/foggy during the winters . The highest temperatures each year in Pakistan , typically rising to above 50 ° C , are usually recorded in Nawabshah District and Sibbi from May to August . On 26 May 2010 record breaking severe heat wave hit the city and the mercury level reached 52 ° C which is the highest temperature ever recorded in Nawabshah . The climate is generally dry and hot , but sometimes the temperature falls to 0 ° C. On January 7 , 2011 temperatures dropped to 4 ° C in the city .

negative: 2011 North American heat wave The 2011 North American heat wave was a deadly summer 2011 heat wave that affected the Southern Plains , Midwestern United States , Eastern Canada , Northeastern United States , and much of the Eastern Seaboard , and had Heat index/Humidex readings reaching upwards of 131 ° F. On a national basis , the heat wave was the hottest in 75 years .

negative: 2013 heatwave in Ireland and the United Kingdom The 2013 heat wave in the United Kingdom and Ireland was a period of unusually hot weather primarily in July 2013 , with isolated warm days in June and August . A prolonged high pressure system over Britain and Ireland caused higher than average temperatures for 19 consecutive days in July , reaching 33.5 ° C at Heathrow and Northolt . Following a brief period of cooler weather at the end of July , temperatures temporarily rose again , peaking at 34.1 ° C on 1 August in the United Kingdom , the warmest the country had seen since July 2006 , and 31.0 ° C in Ireland . At 19 days , the July heatwave was the longest continuous period of hot weather in the UK since August 1997 .   However , in the general sense , Britain did not have an overall exceptional summer ; the country experienced cool low pressure systems brought by an unseasonably low latitude by the jet stream for the 6 summers previous , which made the summer of 2013 more `` welcome '' and feel warmer than other summers . The historical records suggests `` Using the CET record ( for June , July & August ) , the average temperature by that measure was 16.3 degC ( Provisional ) : neither June nor August was exceptionally warm , so this value does not ` rate ' too highly when set against other very warm summer seasons . '' With June being a cool month and August being an Average month , in terms of temperatures the English Central summer temperature ended up being on the average side set up against previous summers since the CET series began in 1659 .

negative: Celsius Celsius , also known as centigrade , is a metric scale and unit of measurement for temperature . As an SI derived unit , it is used by most countries in the world . It is named after the Swedish astronomer Anders Celsius ( 1701 -- 1744 ) , who developed a similar temperature scale . The degree Celsius ( ° C ) can refer to a specific temperature on the Celsius scale as well as a unit to indicate a temperature interval , a difference between two temperatures or an uncertainty . Before being renamed to honour Anders Celsius in 1948 , the unit was called centigrade , from the Latin centum , which means 100 , and gradus , which means steps .   The current scale is based on 0 ° for the freezing point of water and 100 ° for the boiling point of water at 1 atm pressure following a change introduced by Jean-Pierre Christin to reverse the Celsius thermometer scale ( from water boiling at 0 degrees and ice melting at 100 degrees ) . This scale is widely taught in schools today . By international agreement the unit `` degree Celsius '' and the Celsius scale are currently defined by two different temperatures : absolute zero , and the triple point of Vienna Standard Mean Ocean Water ( VSMOW ) , a specially purified water . This definition also precisely relates the Celsius scale to the Kelvin scale , which defines the SI base unit of thermodynamic temperature with symbol K. Absolute zero , the lowest temperature possible , is defined as being precisely 0 K and − 273.15 ° C . The temperature of the triple point of water is defined as exactly 273.16 K at 611.657 Pa pressure .   Thus , the magnitude of one degree Celsius and that of one kelvin are exactly the same and the difference between the two scales ' null points is precisely 273.15 degrees ( and ) .

negative: Kelvin The kelvin is a unit of measure for temperature based upon an absolute scale . It is one of the seven base units in the International System of Units ( SI ) and is assigned the unit symbol K . The Kelvin scale is an absolute , thermodynamic temperature scale using as its null point absolute zero , the temperature at which all thermal motion ceases in the classical description of thermodynamics . The kelvin is defined as the fraction of the thermodynamic temperature of the triple point of water ( exactly 0.01 ° C or 32.018 ° F ) . In other words , it is defined such that the triple point of water is exactly 273.16 K.   The Kelvin scale is named after the Belfast-born , Glasgow University engineer and physicist William Lord Kelvin ( 1824 -- 1907 ) , who wrote of the need for an `` absolute thermometric scale '' . Unlike the degree Fahrenheit and degree Celsius , the kelvin is not referred to or typeset as a degree . The kelvin is the primary unit of temperature measurement in the physical sciences , but is often used in conjunction with the Celsius degree , which has the same magnitude . The definition implies that absolute zero ( 0 K ) is equivalent to -273.15 C.

negative: Cold inflation pressure Cold inflation pressure is the inflation pressure of tires before the car is driven and the tires warmed up . Recommended cold inflation pressure is displayed on the owner 's manual and on the placard ( or sticker ) attached to the vehicle door edge , pillar , glovebox door or fuel filler flap . Drivers are encouraged to make sure their tires are adequately inflated , as suboptimal tire pressure can greatly reduce fuel economy , increase emissions , increased wear on the edges of the tire surface , and can lead to premature failure of the tire . Excessive pressure , on the other hand , may lead to impact-breaks , decrease braking performance , and cause uneven wear ( i.e. greater wear on the center part of the tire surface ) .   Tire pressure is commonly measured in psi in the imperial and US customary systems , bar , which is deprecated but accepted for use with SI or the kilopascal ( kPa ) , which is an SI unit .   Ambient temperature affects the cold tire pressure . Absolute cold tire pressure ( gauge pressure plus atmospheric pressure ) varies directly with the absolute temperature , measured in kelvins .   From physics , the ideal gas law states that PV = nRT where P is absolute pressure , T is absolute temperature ( Kelvin ) , V is the volume ( assumed to be relatively constant in the case of a tire ) , and nR is constant for a given number of molecules of gas . To understand this , assume the tire was filled when it was 300 kelvin ( 80 degrees Fahrenheit ) . If the temperature varies 10 % , i.e. by 30 kelvin ( also 30 Celsius degrees or 54 Fahrenheit degrees ) , the pressure varies 10 % . So if the tire was filled at 80F to 32 psi ( or 47 psi absolute when we add atmospheric pressure ) , the change would be 4.7 psi for this 30 Celsius degree change , or .16 psi per Celsius degree or .1 psi per Fahrenheit degree or 1 psi for every 10 Fahrenheit degrees . Using SI units , that would be 1.1 kPa per kelvin .   Hence , for a tire filled to 32 psi , the approximation usually made is that within the range of normal atmospheric temperatures and pressures :  Tire pressure increases 1 psi for each 10 Fahrenheit degree increase in temperature , or conversely decreases 1 psi for each 10 Fahrenheit degree decrease in temperature and  in SI units , tire pressure increases 1.1 kPa for each 1 Celsius degree increase in temperature , or conversely decreases 1.1 kPa for each 1 Celsius degree decrease in temperature . For tires that need inflation greater than 32psi it might be easier to use a Rule of Thumb of 2 % pressure change for a change of 10 degrees Fahrenheit .  From the table below , one can see that these are only approximations .

negative: Heat wave A heat wave is a prolonged period of excessively hot weather , which may be accompanied by high humidity , especially in oceanic climate countries . While definitions vary , a heat wave is measured relative to the usual weather in the area and relative to normal temperatures for the season . Temperatures that people from a hotter climate consider normal can be termed a heat wave in a cooler area if they are outside the normal climate pattern for that area .   The term is applied both to hot weather variations and to extraordinary spells of hot which may occur only once a century . Severe heat waves have caused catastrophic crop failures , thousands of deaths from hyperthermia , and widespread power outages due to increased use of air conditioning . A heat wave is considered extreme weather , and a danger because heat and sunlight may overheat the human body .

negative: Steam room A steam room is an enclosed space with large amounts of high-temperature steam , creating a high-humidity environment . People sit in this room in a similar way to a sauna ( conversely a hot , but dry atmosphere ) , for relaxation and purported benefits to health and well-being . They can be commonly found in gyms , sanitariums and health resorts . Smaller , standalone steamroom enclosures can also be found in residential buildings .   Steam rooms are commonly maintained at a temperature of 41 degrees Celsius ( 105 Fahrenheit ) or above , with a high humidity of around 100 % adding to the sensation . In comparison , saunas are maintained at a much higher temperature due to the lack of humidity in the air ( often 70-90 degrees Celsius , 158-194 Fahrenheit ) .   The amount of power required for steam generation varies depending on construction style .

negative: Dry-bulb temperature The dry-bulb temperature ( DBT ) is the temperature of air measured by a thermometer freely exposed to the air but shielded from radiation and moisture . DBT is the temperature that is usually thought of as air temperature , and it is the true thermodynamic temperature . It indicates the amount of heat in the air and is directly proportional to the mean kinetic energy of the air molecules . Temperature is usually measured in degrees Celsius ( ° C ) , Kelvin ( K ) , or Fahrenheit ( ° F ) .   Unlike wet bulb temperature , dry bulb temperature does not indicate the amount of moisture in the air . In construction , it is an important consideration when designing a building for a certain climate . Nall called it one of `` the most important climate variables for human comfort and building energy efficiency . ''   DBT is an important variable in Psychrometrics , being the horizontal axis of a Psychrometric chart .

negative: Extreme weather events of 535–536 The extreme weather events of 535 -- 536 were the most severe and protracted short-term episodes of cooling in the Northern Hemisphere in the last 2000 years . The event is thought to have been caused by an extensive atmospheric dust veil , possibly resulting from a large volcanic eruption in the tropics , or debris from space impacting the Earth . Its effects were widespread , causing unseasonal weather , crop failures and famines worldwide .