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Biogeochemistry & Climate. Primary Source: IPCC WG-I Chapter 7 - Couplings Between Changes in the Climate System and Biogeochemistry. Carbon Dioxide (CO 2 ). Pre-industrial: ~ 280 ppm. Sources: Fossil fuels Cement production Deforestation Biomass burning. 75%. Sinks:
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Biogeochemistry & Climate Primary Source: IPCC WG-I Chapter 7 - Couplings Between Changes in the Climate System and Biogeochemistry
Carbon Dioxide (CO2) Pre-industrial: ~ 280 ppm Sources: Fossil fuels Cement production Deforestation Biomass burning 75% Sinks: Rock weathering Plant sediments Ocean uptake Plant growth
Evidence for Anthropogenic? • Carbon Isotopes • O2 depletion • Gradient between NH & SH hemispheres
The Global Carbon Cycle (Black: pre-industrial “natural”Red: 1990s anthropogenic)
Removal Rates for Added CO2 Within 30 yr: ~ 50% Within few C: ~ 80%
CO2 Emissions vs. Removal Effect of Mt. Pinatubo? Cooler temps? More diffuse solar radiation? All into atmosphere Actual amount
Methane (CH4) • Sources: • Biogenic: • Wetlands • Rice • Biomass burning • Ruminants • Fossil fuel mining and distribution • Living vegetation? 70+% NOAA Global Monitoring Division (GMD) Advanced Global Atmospheric Gases Experiments (AGAGE) Mt. Pinatubo? Warm 1998? Economic Incentives? Average Lifetime: ~ 8 yr.
Aerosol Effects Scientific understanding is low (or less)
Remove Aerosols? Constant GHG Aerosol = 0 Constant GHG Constant Aerosol
END Biogeochemistry & Climate