G L O B A L WA RMI N G                                                                                 AT C-IBA R R A     ...
G L O B A L WA RMI N G                                                                                     AT C-IBA R R At...
G L O B A L WA RMI N G                                                                                                 AT ...
G L O B A L WA RMI N G                                                                                 AT C-IBA R R AGloba...
G L O B A L WA RMI N G                                                                                                    ...
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G L O B A L WA RMI N G                                                                                  AT C-IBA R R A    ...
G L O B A L WA RMI N G                                                                                      AT C-IBA R R A...
G L O B A L WA RMI N G                                                                                                    ...
GLOBAL WARMING
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GLOBAL WARMING

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GLOBAL WARMING

  1. 1. G L O B A L WA RMI N G AT C-IBA R R A GLOBAL WARMINGEtymologyThe term global warming was probably first used in its modern sense on 8 August 1975 ina science paper by Wally Broecker in the journal Science called "Are we on the brink of apronounced global warming?". Broeckers choice of words was new and represented asignificant recognition that the climate was warming; previously the phrasing used byscientists was "inadvertent climate modification," because while it was recognized humanscould change the climate, no one was sure which direction it was going. The NationalAcademy of Sciences first used global warming in a 1979 paper called the CharneyReport, which said: "if carbon dioxide continues to increase, [we find] no reason to doubtthat climate changes will result and no reason to believe that these changes will benegligible." The report made a distinction between referring to surface temperaturechanges as global warming, while referring to other changes caused by increased CO2 asclimate change.Global warming became more widely popular after 1988 when NASA climate scientistJames Hansen used the term in a testimony to Congress. He said: "global warming hasreached a level such that we can ascribe with a high degree of confidence a cause andeffect relationship between the greenhouse effect and the observed warming." His1
  2. 2. G L O B A L WA RMI N G AT C-IBA R R Atestimony was widely reported and afterwardglobal warming was commonly used by thepress and in public discourse:  Effects of global warming on oceans  Environmental impact of the coal industry  Glossary of climate change  History of climate change science  Index of climate change articlesScienceGlobal warming refers to the rising average temperature of Earths atmosphere andoceans since the late 19th century, as well as its projected continuation. Since the early20th century, Earths mean surface temperature has increased by about 0.8 °C (1.4 °F),with about two-thirds of the increase occurring since 1980. Warming of the climate systemis unequivocal, and scientists are more than 90% certain that it is primarily caused byincreasing concentrations of greenhouse gases produced by human activities suchasdeforestation and the burning of fossil fuels. These findings are recognized by thenational science academies of all major industrialized nations.Climate model projections are summarized in the 2007 Fourth Assessment Report (AR4)by the Intergovernmental Panel on Climate Change (IPCC). They indicate that during the21st century the global surface temperature is likely to rise a further 1.1 to 2.9 °C (2 to 5.2°F) for their lowest emissions scenario and 2.4 to 6.4 °C (4.3 to 11.5 °F) for their highest.The ranges of these estimates arise from the use of models with differing sensitivity togreenhouse gas concentrations.An increase in global temperature will cause sea levels to rise and will change the amountand pattern of precipitation, as well as cause a probable expansion of subtropicaldeserts.Warming is expected to be strongest in the Arctic and would be associated with thecontinuing retreat of glaciers, permafrost and sea ice. Other likely effects of the warming2
  3. 3. G L O B A L WA RMI N G AT C-IBA R R Ainclude a more frequent occurrence of extreme-weather events including heat waves,droughts and heavy rainfall, species extinctions due to shifting temperature regimes, andchanges in crop yields. Warming and related changes will vary from region to regionaround the globe, with projections being more robust in some areas than others. If globalmean temperature increases to 4 °C (7.2 °F) above preindustrial levels, the limits forhuman adaptation are likely to be exceeded in many parts of the world, while the limits ofadaptation for natural systems would largely be exceeded throughout the world. Hence,the ecosystem services upon which human livelihoods depend would not be preserved.Policy responses to global warming include mitigation by emissions reduction, adaptationto its effects, and possible future geoengineering. Most countries are parties to the UnitedNations Framework Convention on Climate Change (UNFCCC), whose ultimate objectiveis to prevent dangerous anthropogenic (i.e., human-induced) climate change. Parties tothe UNFCCC have adopted a range of policies designed to reduce greenhouse gasemissions :9 and to assist in adaptation to global warming. Parties to the UNFCCC haveagreed that deep cuts in emissions are required, and that future global warming should belimited to below 2.0 °C (3.6 °F) relative to the pre-industrial level. A 2011 report ofanalyses by the United Nations Environment Programme[23] andInternational EnergyAgency suggest that efforts as of the early 21st century to reduce emissions may beinadequately stringent to meet the UNFCCCs 2 °C target.Main article:T hi s arti cl e i s a b o ut th e c ur r e nt c h a n g e in E a rth s cli m at e .3
  4. 4. G L O B A L WA RMI N G AT C-IBA R R AGlobal mean land-ocean temperature change from 1880–2011, relative to the 1951–1980mean. The black line is the annual mean and the red line is the 5-year running mean. Thegreen bars show uncertainty estimates. Source: NASA GISSThe map shows the 10-year average (2000–2009) global mean temperature anomalyrelative to the 1951–1980 mean. The largest temperature increases are in the Arctic andthe Antarctic Peninsula. Source:NASA Earth Observatory4
  5. 5. G L O B A L WA RMI N G AT C-IBA R R AFossil fuel related CO2 emissions compared to five of IPCCs emissions scenarios. Thedips are related to global recessions. Data from IPCC SRES scenarios; Data spreadsheetincluded with International Energy Agencys "CO2 Emissions from Fuel Combustion 2010 1– Highlights"; andSupplemental IEA data. Image source:Skeptical.Reconstructed temperatureTwo millennia of mean surface temperatures according to different reconstructions fromclimate proxies, each smoothed on a decadal scale, with theinstrumental temperaturerecord overlaid in black.Evidence for warming of the climate system includes observed increases in global averageair and ocean temperatures, widespread melting of snow and ice, and rising globalaverage sea level. The Earths average surface temperature, expressed as a linear trend,rose by0.74±0.18 °C over the period 1906–2005. The rate of warming over the last half ofthat period was almost double that for the period as a whole (0.13±0.03 °C per decade,versus0.07±0.02 °C per decade). The urban heat island effect is very small, estimated toaccount for less than 0.002 °C of warming per decade since 1900.[28] Temperatures in the1 http://www.aida-americas.org/en/pubs/human-rights-impacts-climate-change-latin-america? gclid=CIHxot_V9LACFQS0nQodiXtm6A5
  6. 6. G L O B A L WA RMI N G AT C-IBA R R Alowertroposphere have increased between 0.13 and 0.22 °C (0.22 and 0.4 °F) per decadesince 1979, according to satellite temperature measurements. Climate proxies show thetemperature to have been relatively stable over the one or two thousand years before1850, with regionally varying fluctuations such as the Medieval Warm Period and the LittleIce Age.“Recent estimates by NASAs Goddard Institute for Space Studies (GISS) and the NationalClimatic Data Center show that 2005 and 2010 tied for the planets warmest year sincereliable, widespread instrumental measurements became available in the late 19thcentury, exceeding 1998 by a few hundredths of a degree. Estimates by the ClimaticResearch Unit (CRU) show 2005 as the second warmest year, behind 1998 with 2003 and2010 tied for third warmest year, however, "the error estimate for individual years ... is atleast ten times larger than the differences between these three years." The WorldMeteorological Organization (WMO) statement on the status of the global climate in 2010explains that, "The 2010 nominal value of +0.53 °C ranks just ahead of those of 2005(+0.52 °C) and 1998 (+0.51 °C), although the differences between the three years are not 2statistically significant..."NOAA graph of Global Annual Temperature Anomalies 1950–2011, showing the El Niño-Southern OscillationTemperatures in 1998 were unusually warm because global temperatures are affected bythe El Niño-Southern Oscillation (ENSO), and the strongest El Niño in the past centuryoccurred during that year. Global temperature is subject to short-term fluctuations thatoverlay long term trends and can temporarily mask them. The relative stability in2. https://www.wikipedia.com6
  7. 7. G L O B A L WA RMI N G AT C-IBA R R Atemperature from 2002 to 2009 is consistent with such an episode. 2010 was also an ElNiño year. On the low swing of the oscillation, 2011 as an La Niña year was cooler but itwas still the 11th warmest year since records began in 1880. Of the 13 warmest yearssince 1880, 11 were the years from 2001 to 2011. Over the more recent record, 2011 wasthe warmest La Niña year in the period from 1950 to 2011, and was close to 1997 whichwas not at the lowest point of the cycle.Temperature changes vary over the globe. Since 1979, land temperatures have increasedabout twice as fast as ocean temperatures (0.25 °C per decade against 0.13 °C perdecade). Ocean temperatures increase more slowly than land temperatures because ofthe larger effective heat capacity of the oceans and because the ocean loses more heat byevaporation. The Northern Hemispherewarms faster than the Southern Hemispherebecause it has more land and because it has extensive areas of seasonal snow and sea-ice cover subject to ice-albedo feedback. Although more greenhouse gases are emitted inthe Northern than Southern Hemisphere this does not contribute to the difference inwarming because the major greenhouse gases persist long enough to mix betweenhemispheres.The thermal inertia of the oceans and slow responses of other indirect effects mean thatclimate can take centuries or longer to adjust to changes in forcing. Climate commitmentstudies indicate that even if greenhouse gases were stabilized at 2000 levels, a furtherwarming of about 0.5 °C (0.9 °F) would still occur.Initial causes of temperature changes (external forcings)7
  8. 8. G L O B A L WA RMI N G AT C-IBA R R AGreenhouse effect schematic showing energy flows between space, the atmosphere, andearths surface. Energy exchanges are expressed in watts per square meter (W/m2).This graph, known as the Keeling Curve, shows the increase of atmosphericcarbondioxide (CO2) concentrations from 1958–2008. Monthly CO2measurements displayseasonal oscillations in an upward trend; each years maximum occurs during theNorthernHemispheres late spring, and declines during its growing season as plants remove someatmospheric CO2.External forcing refers to processes external to the climate system (though not necessarilyexternal to Earth) that influence climate. Climate responds to several types of externalforcing, such as radiative forcing due to: changes in atmospheric composition8
  9. 9. G L O B A L WA RMI N G AT C-IBA R R A changes in solar luminosity volcanic eruptions variations in earth´sorbitaround the sun Climate modelsGlobal climate modelCalculations of global warming prepared in or before 2001 from a range of climate modelsunder the SRES A2 emissions scenario, which assumes no action is taken to reduceemissions and regionally divided economic development.The geographic distribution of surface warming during the 21st century calculated by theHadCM3 climate model if a business as usual scenario is assumed for economic growthand greenhouse gas emissions. In this figure, the globally averaged warming correspondsto 3.0 °C (5.4 °F).A climate model is a computerized representation of the five components of the climatesystem: Atmosphere, hydrosphere, cryosphere, land surface, and biosphere.[98] Suchmodels are based on physical principles including fluid dynamics, thermodynamics andradiative transfer. There can be components which represent air movement, temperature,clouds, and other atmospheric properties; ocean temperature, salt content, and circulation;ice cover on land and sea; the transfer of heat and moisture from soil and vegetation to theatmosphere; chemical and biological processes; and others.9
  10. 10. G L O B A L WA RMI N G AT C-IBA R R A Cli m a t e m o d el Co mpon ent s P rin cipl e s R e pr e s e n t Atmosphre Fluid dynamics Air movement Circulation Hydrosphere Thermo dynamics Temperature Criosphere Radistive transfer Salt content Climate change and agricultureMaize ProductionUnder present trends, by 2030, maize production in Southern Africa could decrease by upto 30% while rice, millet and maize in South Asia could decrease by up to 10%. By 2080,yields in developing countries could decrease by 10% to 25% on average while India couldsee a drop of 30% to 40%.[129] By 2100, while the population of three billion is expectedto double, rice and maize yields in thetropics are expected to decrease by 20–40%because of higher temperatures without accounting for the decrease in yields as a result ofsoil moisture and water supplies stressed by rising temperatures.Future warming of around 3 °C (by 2100, relative to 1990–2000) could result in increasedcrop yields in mid- and high-latitude areas, but in low-latitude areas, yields could decline,increasing the risk of malnutrition. A similar regional pattern of net benefits and costs couldoccur for economic (market-sector) effects. Warming above 3 °C could result in cropyields falling in temperate regions, leading to a reduction in global food production.10
  11. 11. G L O B A L WA RMI N G AT C-IBA R R A Habitat inundationClimate refugeeIn small islands and megadeltas, inundation as a result of sea level rise is expected tothreaten vital infrastructure and human settlements. This could lead to issues ofstatelessness for population from countries including the Maldives and Tuvaluandhomelessness in countries with low lying areas such as Bangladesh. Climate change mitigationFee and dividendReducing the amount of future climate change is called mitigation of climate change. TheIPCC defines mitigation as activities that reduce greenhouse gas (GHG) emissions, orenhance the capacity of carbon sinks to absorb GHGs from the atmosphere. Manycountries, both developing and developed, are aiming to use cleaner, less polluting,technologies.[59]:192 Use of these technologies aids mitigation and could result insubstantial reductions in CO2 emissions. Policies include targets for emissions reductions,increased use of renewable energy, and increased energy efficiency. Studies indicatesubstantial potential for future reductions in emissions.In order to limit warming to within the lower range described in the IPCCs "SummaryReport for Policymakers"[137] it will be necessary to adopt policies that will limitgreenhouse gas emissions to one of several significantly different scenarios described inthe full report. This will become more and more difficult with each year of increasingvolumes of emissions and even more drastic measures will be required in later years tostabilize a desired atmospheric concentration of greenhouse gases. Energy-relatedcarbon-dioxide (CO2) emissions in 2010 were the highest in history, breaking the priorrecord set in 2008.11
  12. 12. G L O B A L WA RMI N G AT C-IBA R R ASince even in the most optimistic scenario, fossil fuels are going to be used for years tocome, mitigation may also involve carbon capture and storage, a process that traps CO2produced by factories and gas or coal power stations and then stores it, usuallyunderground. AdaptationAdaptation to global warmingOther policy responses include adaptation to climate change. Adaptation to climatechange may be planned, either in reaction to or anticipation of climate change, orspontaneous, i.e., without government intervention. The ability to adapt is closely linked tosocialand economic development. Even societies with high capacities to adapt are stillvulnerable to climate change. Planned adaptation is already occurring on a limited basis.The barriers, limits, and costs of future adaptation are not fully understood. GeoengineeringGeoengineering, the deliberate modification of the climate, has been investigated as apossible response to global warming, e.g. ByNASA, and the Royal Society,. Techniquesunder research fall generally into the categories solar radiation management andcarbondioxide removal, although various other schemes have been suggested. Research is at a 3generally early stage, with no large-scale schemes currently deployed.3 Htttp://www.aida.com/globalwarming/d3514512
  13. 13. G L O B A L WA RMI N G AT C-IBA R R ATABLE OF CONTEXTGLOBAL WARMING..........................................................................................................................1Etymology............................................................................................................................................1Science..................................................................................................................................................2Main article: .........................................................................................................................................3Reconstructed temperature...................................................................................................................4Climate models ....................................................................................................................................8Global climate model ..........................................................................................................................8Climate change and agriculture...........................................................................................................9Maize Production..................................................................................................................................9Habitat inundation..............................................................................................................................10Climate refugee.................................................................................................................................10Climate change mitigation.................................................................................................................10Fee and dividend................................................................................................................................10Adaptation...........................................................................................................................................11Adaptation to global warming...........................................................................................................11Geoengineering...................................................................................................................................1113

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