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The Current Interglacial (Holocene)

The Current Interglacial (Holocene). AOS 528, 11/29/07. The Holocene. Approximately 11,600 years ago to the present Increasingly modified by human activities Land use causes local climate effects Altered atmospheric composition causes global climate effects

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The Current Interglacial (Holocene)

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  1. The Current Interglacial (Holocene) AOS 528, 11/29/07

  2. The Holocene • Approximately 11,600 years ago to the present • Increasingly modified by human activities • Land use causes local climate effects • Altered atmospheric composition causes global climate effects • Records of long and short-term climate change: • Alpine glaciers • Monsoons • El Niño-Southern Oscillation

  3. Holocene Climate Forcings • Orbital Variations • Volcanic eruptions • Changes in amplitude and occurrence • Solar luminosity variations • Much study (Particularly at NASA. Why?), • Minimal effects • Greenhouse gas concentrations • Waning Ice Sheets • Effects on albedo and atmospheric circulation

  4. Holocene Climate Forcings • Orbital Variations • Volcanic eruptions • Changes in amplitude and occurrence • Solar luminosity variations • Much study (Particularly at NASA. Why?), • Minimal effects • Greenhouse gas concentrations • Waning Ice Sheets • Effects on albedo and atmospheric circulation

  5. The Holocene and Orbital Variations

  6. N. HEM. SUMMER INSOLATION Incident Shortwave Radiation over Land, Ocean and Globally Incident Shortwave Radiation at 10Kyr, 6Kyr, and 0Kyr BP Predicted SST Specified SST

  7. INSOLATION and PRECIP EFFECTS Summer Radiation (W/m2) NW African Climate Simulated Precipitation Change in centimeters www.cgd.ucar.edu/asr/asr03/ccr/index.html deMenocal et al., Science, 2000

  8. INSOLATION and PRECIP EFFECTS Effect of Insolation on the African Monsoon Source: PMIP (Paleoclimate Model Intercomparison Project) and the Global Lake Status Database, (GLSDB: Kohfeld and Harrison, 2000, Harrison et al., 2003)

  9. Holocene Greenhouse Gases • Known from ice cores • Carbon Dioxide (CO2) • 10-8kyr: decreases 7ppm • 8kyr-preindustrial: increases 20ppm • Methane (CH4) • 10-6kyr: decreases 150ppb • 6-preindustrial: increases 150ppb • Nitrous Oxide (N2O) • 10-8kyr: decreases 10ppb • 8-2kyr: increases 10ppb

  10. CO2 CH4 N2O Holocene Greenhouse Gas Forcing T Total combined Holocene greenhouse gas forcing was about 0.5 W/m2 • CO2 = 0.4 W/m2 • N2O+CH4 = 0.1 W/m2 Flueckiger et al., 2002

  11. The Anthropocene? Why were GHG concentrations varying before the industrial age? http://www.realclimate.org/index.php/archives/2005/12/early-anthropocene-hyppothesis/ Ruddiman, 2005

  12. Term Paper Instructions 3. Required sections: • Introduction • Model Description • Experiment Description • Results • Discussion (interpret and contextualize results) • Conclusions (and Future Work)

  13. Term Paper Instructions • Due dates: December 8th and 13th (midnight) • Term Paper Instructions • 10-15 pages, single-spaced including: • Title page • Figures • References (at least 5) • 1 inch margins, 12pt font • All figures must have captions • Each person must contribute some material

  14. Term Papers Due Dec. 13th Presentations: Thursday, December 6th (during class) Group 2: Phillips, Schiferl The Effectiveness of the Kyoto Protocol Group 7: Schmidt, Bruskewitz, Serwe: Title? Group 8: Schuh, Moore, Olson Effects of Global Warming on Agriculture Production in the Midwest Group 9: Kirchner, Shewczyk, Welhouse Global Climate Change's Effects On Agriculture Group 10: Franklin, Obbink, Orland The Effects of Orbital Forcings During Mid-Pliocene Global Warming

  15. Term Papers Due Dec. 8th Presentations: Thursday, December 20th (10:05am) Group 1: Lubcaynka, Moua, Propheter US and China's Affect on Global Warming Group 3: Caruso, Maloney, Schmelzer Title? Group 4: Schreiber, Brown "Peak Oil" Predictions and Their Effect on Future Warming Group 5: Asuma, Caves, Koch A Comparison of Global Climate Effects Due to Varying Rates of Methane Introduction Group 6: Marsicek, Ronnei, McCarville Using Drought Index to Analyze Potential Impacts on the Tropical Rainforest By Increasing CO2 and Solar Luminosity Group 11: Hladish, Kampa A Potential Glacial Maximum in the Future?

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