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Greenhouse Gases and climate change

Greenhouse Gases and climate change. Equilibrium: Energy/time in = Energy/time out Earth gains energy from the sun, by radiation Earth loses energy to outer space, by radiation Radiated power proportional to T 4 (T in Kelvins) With no atmosphere, Earth’s average temp would be -18 C.

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Greenhouse Gases and climate change

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  1. Greenhouse Gases and climate change

  2. Equilibrium: Energy/time in = Energy/time out • Earth gains energy from the sun, by radiation • Earth loses energy to outer space, by radiation • Radiated power proportional to T4 (T in Kelvins) • With no atmosphere, Earth’s average temp would be -18 C

  3. The greenhouse effect: absorption and re-radiation of em waves Light radiated outward from the earth’s surface is absorbed by molecules in the atmosphere Molecules re-radiate that energy in a random direction– some continues outward; some is redirected back towards the earth’s surface

  4. http://en.wikipedia.org/wiki/Image:Atmospheric_Transmission.pnghttp://en.wikipedia.org/wiki/Image:Atmospheric_Transmission.png

  5. Greenhouse effect: some of the energy radiated outward by the earth is absorbed by greenhouse gases, and reradiated • Thus the earth’s surface is +14 C on average, much warmer than the -18 C we would be have the atmosphere. • In equilibrium (power in = power out), the temperature remains very stable (averaged over the globe).

  6. Greenhouse Gases and Global Warming http://yosemite.epa.gov/oar/globalwarming.nsf/content/climate.html

  7. Deforestation by logging is not a “feedback” mechanism

  8. http://www.youtube.com/watch?v=YegdEOSQotE&feature=related

  9. Current Climate Forcings http://www.ipcc.ch/present/graphics.htm

  10. http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-spm.pdf, p 10

  11. Temperature Changes in the Last Millennium http://yosemite.epa.gov/oar/globalwarming.nsf/content/climate.html

  12. http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-spm.pdf, p. 2

  13. CO2 Increase Observed at Mauna Loa Since 1974 Average slope =1.54 ppm CO2/year http://gaw.kishou.go.jp/wdcgg/PlotData.php?file=co2/monthly/mlo519n0.dat

  14. CO2 Increase Observed at South Pole Since 1974 This increase is observed everywhere, even at the South Pole. Increase is occurring over the entire earth http://gaw.kishou.go.jp/wdcgg/PlotData.php?file=co2/monthly/spo789s0.dat

  15. CO2 Increase Observed At Siple in Recent Past Siple Station, Antarctica75°55' S, 83°55' W The increase in CO2 is accelerating. http://cdiac.esd.ornl.gov/trends/co2/siple.htm

  16. CO2 Fluctuations Obtained from Vostok Ice Core Samples over the Last 400,000 yrs Vostok, Antarctica 78°28' S, 106°48'E3488 m above MSL 1 kyr = 1 kilo year = 1000 years http://cdiac.esd.ornl.gov/trends/co2/graphics/vostok.co2.gif

  17. Temperature Fluctuations Obtained from Vostok Ice Core Samples over the Last 400,000 yrs “Because isotopic fractions of the heavier 18-O and D in snowfall are temperature-dependent and a strong spatial correlation exists between the annual mean temperature and the mean isotopic ratio (18O or D) of precipitation, it is possible to derive ice-core climate records… [This was] completed in January 1998, reaching a depth of 3623 m, the deepest ice core ever recovered (Petit et al. 1997, 1999). The resulting core allows the ice core record of climate properties at Vostok to be extended to ~420 kyr BP.” Source: http://cdiac.esd.ornl.gov/trends/temp/vostok/graphics/tempplot5.gif

  18. Correlation Between CO2 and ΔT† Slope = 0.883±0.063˚C / 10 ppm CO2 Current CO2 Regression extrapolated to current CO2 level of 380 ppm. The red bar indicates 95% confidence limits on predicted temperature change. Regression line shown with 95 % confidence intervals Data analysis by JD http://cdiac.ornl.gov/trends/trends.htm †J.-M. Barnola, D. Raynaud, C. Lorius Laboratoire de Glaciologie et de Géophysique de l'Environnement, CNRS, BP96, 38402 Saint Martin d'Heres Cedex, France N.I. Barkov Arctic and Antarctic Research Institute, Beringa Street 38, 199397, St. Petersburg, Russia, and J.R. Petit, D. Raynaud, and C. Lorius, Laboratoire de Glaciogie et Géophysique de l'Environnement, CNRS, Saint Martin d'Hères Cedex, France, J. Jouzel and G. Delaygue, Laboratoire des Sciences du Climat et de l'Environnement (LSCE), CEA/CNRS, L'Orme des Merisiers, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France

  19. Temperature Increases Are Observed In Northern and Southern Hemispheres Carbon Dioxide Information Analysis Center http://cdiac.esd.ornl.gov/trends/temp/lugina/graphics/allann.jpg

  20. Temperature Increases Are Observed On Both Land And Ocean Surfaces http://www.ncdc.noaa.gov/img/climate/research/anomalies/triad_pg.gif

  21. Temperature Increases Are Greater in the Polar Regions http://cdiac.esd.ornl.gov/trends/temp/lugina/annual.html

  22. http://www.ipcc.ch/pdf/assessment-report/ar4/wg2/ar4-wg2-spm.pdf, p. 8

  23. http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-spm.pdf, p 11

  24. http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-spm.pdf, p. 6

  25. Global per capita CO2 Emission Estimates Have Remained Constant http://cdiac.esd.ornl.gov/trends/emis/glo.htm

  26. Two CO2 Scenarios About 50% of a CO2 increase will be removed from the atmosphere within 30 years, and a further 30% will be removed within a few centuries. The remaining 20% may stay in the atmosphere for many thousands of years. http://www.ipcc.ch/present/graphics.htm http://www.ipcc.ch/present/graphics.htm

  27. http://www.ipcc.ch/pdf/assessment-report/ar4/wg2/ar4-wg2-spm.pdf, p. 8

  28. http://www.ipcc.ch/pdf/assessment-report/ar4/wg2/ar4-wg2-spm.pdf, p. 8

  29. http://www.youtube.com/watch?v=w9SGw75pVas&feature=player_embeddedhttp://www.youtube.com/watch?v=w9SGw75pVas&feature=player_embedded • http://www.ipcc.ch/ • http://www.epa.gov/climatechange/

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