humble3d Posted March 22, 2012 Share Posted March 22, 2012 The evidence for rapid climate change is compelling:The Earth's climate has changed throughout history. Just in the last 650,000 years there have been sevencycles of glacial advance and retreat, with the abrupt end of the last ice age about 7,000 years ago markingthe beginning of the modern climate era — and of human civilization. Most of these climate changes areattributed to very small variations in Earth’s orbit that change the amount of solar energy our planetreceives. "Scientific evidence for warming of the climate system is unequivocal." - Intergovernmental Panel on Climate Change The current warming trend is of particular significance because most of it is very likely human-induced andproceeding at a rate that is unprecedented in the past 1,300 years.1Earth-orbiting satellites and other technological advances have enabled scientists to see the big picture,collecting many different types of information about our planet and its climate on a global scale. Studyingthese climate data collected over many years reveal the signals of a changing climate.Certain facts about Earth's climate are not in dispute:The heat-trapping nature of carbon dioxide and other gases was demonstrated in the mid-19th century.2Their ability to affect the transfer of infrared energy through the atmosphere is the scientific basis of manyJPL-designed instruments, such as AIRS. Increased levels of greenhouse gases must cause the Earth towarm in response.Ice cores drawn from Greenland, Antarctica, and tropical mountain glaciers show that the Earth’s climateresponds to changes in solar output, in the Earth’s orbit, and in greenhouse gas levels. They also show thatin the past, large changes in climate have happened very quickly, geologically-speaking: in tens of years,not in millions or even thousands.3The evidence for rapid climate change is compelling:Republic of Maldives: Vulnerable to sea level rise Sea level riseGlobal sea level rose about 17 centimeters (6.7 inches) in the last century. The rate in the last decade,however, is nearly double that of the last century.4Global temperature riseAll three major global surface temperature reconstructions show that Earth has warmed since 1880. 5 Mostof this warming has occurred since the 1970s, with the 20 warmest years having occurred since 1981 andwith all 10 of the warmest years occurring in the past 12 years. 6 Even though the 2000s witnessed a solaroutput decline resulting in an unusually deep solar minimum in 2007-2009, surface temperatures continue toincrease. 7Warming oceansThe oceans have absorbed much of this increased heat, with the top 700 meters (about 2,300 feet) of oceanshowing warming of 0.302 degrees Fahrenheit since 1969.8Flowing meltwater from the Greenland ice sheetShrinking ice sheetsThe Greenland and Antarctic ice sheets have decreased in mass. Data from NASA's Gravity Recovery andClimate Experiment show Greenland lost 150 to 250 cubic kilometers (36 to 60 cubic miles) of ice per yearbetween 2002 and 2006, while Antarctica lost about 152 cubic kilometers (36 cubic miles) of ice between2002 and 2005.Visualization of the 2007 Arctic sea ice minimum Declining Arctic sea iceBoth the extent and thickness of Arctic sea ice has declined rapidly over the last several decades. 9The disappearing snowcap of Mount Kilimanjaro, from space. Glacial retreatGlaciers are retreating almost everywhere around the world — including in the Alps, Himalayas, Andes,Rockies, Alaska and Africa.10Extreme eventsThe number of record high temperature events in the United States has been increasing, while the numberof record low temperature events has been decreasing, since 1950. The U.S. has also witnessed increasingnumbers of intense rainfall events.11Ocean acidificationSince the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about30 percent.12,13 This increase is the result of humans emitting more carbon dioxide into the atmosphereand hence more being absorbed into the oceans. The amount of carbon dioxide absorbed by the upperlayer of the oceans is increasing by about 2 billion tons per year.14,15References1 IPCC Fourth Assessment Report, Summary for Policymakers, p. 5B.D. Santer et.al., “A search for human influences on the thermal structure of the atmosphere,” Nature vol382, 4 July 1996, 39-46Gabriele C. Hegerl, “Detecting Greenhouse-Gas-Induced Climate Change with an Optimal FingerprintMethod,” Journal of Climate, v. 9, October 1996, 2281-2306V. Ramaswamy et.al., “Anthropogenic and Natural Influences in the Evolution of Lower StratosphericCooling,” Science 311 (24 February 2006), 1138-1141B.D. Santer et.al., “Contributions of Anthropogenic and Natural Forcing to Recent Tropopause HeightChanges,” Science vol. 301 (25 July 2003), 479-483.2 In the 1860s, physicist John Tyndall recognized the Earth's natural greenhouse effect and suggested thatslight changes in the atmospheric composition could bring about climatic variations. In 1896, a seminalpaper by Swedish scientist Svante Arrhenius first speculated that changes in the levels of carbon dioxide inthe atmosphere could substantially alter the surface temperature through the greenhouse effect.3 National Research Council (NRC), 2006. Surface Temperature Reconstructions For the Last 2,000 Years.National Academy Press, Washington, DC.4 Church, J. A. and N.J. White (2006), A 20th century acceleration in global sea level rise, GeophysicalResearch Letters, 33, L01602, doi:10.1029/2005GL024826.The global sea level estimate described in this work can be downloadedfrom the CSIRO website.5http://www.ncdc.noaa.gov/oa/climate/research/ anomalies/index.htmlhttp://www.cru.uea.ac.uk/cru/data/temperaturehttp://data.giss.nasa.gov/gistemp6 T.C. Peterson et.al., "State of the Climate in 2008," Special Supplement to the Bulletin of the AmericanMeteorological Society, v. 90, no. 8, August 2009, pp. S17-S18.7 I. Allison et.al., The Copenhagen Diagnosis: Updating the World on the Latest Climate Science, UNSWClimate Change Research Center, Sydney, Australia, 2009, p. 11http://www.giss.nasa.gov/research/news/20100121/http://science.nasa.gov/headlines/y2009/ 01apr_deepsolarminimum.htm8 Levitus, et al, "Global ocean heat content 1955–2008 in light of recently revealed instrumentationproblems," Geophys. Res. Lett. 36, L07608 (2009).9 L. Polyak, et.al., “History of Sea Ice in the Arctic,” in Past Climate Variability and Change in the Arctic andat High Latitudes, U.S. Geological Survey, Climate Change Science Program Synthesis and AssessmentProduct 1.2, January 2009, chapter 7R. Kwok and D. A. Rothrock, “Decline in Arctic sea ice thickness from submarine and ICESAT records:1958-2008,” Geophysical Research Letters, v. 36, paper no. L15501, 2009http://nsidc.org/sotc/sea_ice.html10 National Snow and Ice Data CenterWorld Glacier Monitoring Service11 http://lwf.ncdc.noaa.gov/extremes/cei.html12 http://www.pmel.noaa.gov/co2/story/What+is+Ocean+Acidification%3F (Note: The pH of surface oceanwaters has fallen by 0.1 pH units. Since the pH scale is logarithmic, this change represents approximately a30 percent increase in acidity.)13 http://www.pmel.noaa.gov/co2/story/Ocean+Acidification14 C. L. Sabine et.al., “The Oceanic Sink for Anthropogenic CO2,” Science vol. 305 (16 July 2004), 367-37115 Copenhagen Diagnosis, p. 36.http://climate.nasa.gov/evidence/SIDE NOTE:There is one forgotten item,The year 1966-70 where children were taught the earth has a 22.5 degree lean on its axis.The year 1988- 92 where children were taught the earth has a 23 degree lean on its axis.What's the bet its now heading towards or is now 23.5 degrees?The more it leans the more hotter summers and colder winters for the northern hemisphere...And, it begs the question:"Is it better to live on Earth's equator ? Link to comment Share on other sites More sharing options...
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