Climate and the Carbon Cycle

1. Climate and the Carbon Cycle Gretchen Keppel-Aleks California Institute of Technology 16 October 2010

2. The Global Carbon Cycle Fossil Fuel Source ~8 Atmosphere Ocean exchange ~70 Land exchange ~120 Ocean Uptake ~2 Land Uptake ~3 Ocean Biosphere (LeQuere 2009) fluxes [PgC yr-1] Carbon is transported through natural reservoirs: the atmosphere, the biosphere, and the ocean

3. Earth’s Carbon Cycle Respiration Photosynthesis Decomposition NOAA ESRL Fluxes between the biosphere and the atmosphere set the seasonal patterns in atmospheric CO2

4. Earth’s Carbon Cycle Atmospheric CO2 Respiration Photosynthesis

5. Earth’s Carbon Cycle Temperature ? Atmospheric CO2 Respiration Photosynthesis Feedbacks between climate and the carbon cycle affect natural fluxes of CO2

6. Terrestrial Carbon Cycle Humidity, Precipitation,Regional Climate ? Temperature ? ? Atmospheric CO2 Respiration Photosynthesis Feedbacks between climate and the carbon cycle affect natural fluxes of CO2

7. Ocean CO2 and Acidification (Hoegh-Guldberg et al., 2007 , Doney et al., 2009) Changes in the concentration of atmospheric CO2 impact the ocean

8. Ocean CO2 and Acidification (Hoegh-Guldberg et al., 2007 , Doney et al., 2009) Changes in the concentration of atmospheric CO2 impact the ocean

9. Climate - Carbon Cycle Links Carbon is present in natural reservoirs (atmosphere, ocean, biosphere) The growth of carbon in the atmospheric reservoir is the major contributor to climate change Climate change will affect the cycling of carbon through natural reservoirs Understanding carbon cycle feedbacks is crucial to predicting future climate