1. Pre-anthropogenic C cycle and recent perturbations

2. Control of atmospheric pCO2 on different time scales
Time scale Components Processes
yrs lithosphere volcanism, burial, biosphere weathering
yrs hydrosphere ocean circulation and biosphere biogeochemical cycling, carbonate dissolution
10 – 102 yrs biosphere fossil fuel burning,
land ecosystem shifts, land use changes

3. CO2 and temperature records
2009
(386 ppm)

5. Human perturbation of the global carbon budget
GtC
fossil fuel emissions
7.5 83%
Source
deforestation
1.5 17%
CO2 flux (Pg C y-1)
atmospheric CO2
4.2 45%
Sink
land
2.6 29%
Atmospheric CO2 accumulation is meaured/
The source terms are estimated from energy consumption and deforestation.
The ocean sink is modelled
The land sink is the residual from closing the balance (it is not directly measured).
More details are:
ocean
2.3 26%
Time (y)
Global Carbon Project (2008) 5

6. Land carbon cycling

7. Modelled land carbon storages as functions of pCO2 and T
Gerber et al
(2004), GCB

8. Climate-carbon model sensitivities to CO2 and T
Friedensten et al
(2006), JC

9. Ocean chlorophyll distribution

10. Air-sea exchange of CO2 from observations

11. “Observed” ocean uptake of anthropogenic CO2

12. DCESS Earth System Model
Sun
Atmosphere
Ocean
Land Biosphere
Lithosphere
Ocean Sediment
(Shaffer et al (2008) in Geoscientific Model Development)

13. Model geometry and some components
Atmosphere
transport
Land
biomass
Volcanic input
Weathering
River inflow

14. Ocean and ocean sediment submodels

15. Model fit to ocean data for standard parameter values

16. DCESS model simulation from 1765 to 2000 (1)

17. DCESS model simulation from 1765 to 2000 (2)

18. Standard vs no ocean heat uptake

19. Standard vs no ocean CO2 uptake

20. Standard vs no ocean heat nor CO2 uptake

21. Some positive climate feedbacks via oceanic CO2
*T   CO2 solubility   pCO2   T 
*T  CP   pCO2   T 
T   precip , winds   dust   NP   pCO2   T 
T  MH   DIC   pCO2   T 
(* included in the DCESS Earth System model)

22. Some negative climate feedbacks via oceanic CO2
* T   sea ice   NP   pCO2   T 
*T   weathering   runoff   NP   pCO2   T 
* pCO2  CO3   Alk   pCO2   T 
pCO2  CO3   CP   pCO2   T 
(* included in the DCESS Earth System model)

23. Scenario greenhouse gas and aerosol forcings
Total anthropogenic
carbon emissions (GtC) A
A1B B AG
Total emissions by 2007
were 522 GtC.

24. Future Earth System projections for SRES B1 and A2 forcing
(Shaffer et al. (2009)
In Nature Geoscience)

25. 1.5 million year run for doubling lithosphere CO2 outgassing

26. Methane Hydrate
Present estimates of MH in the ocean sediment center around GtC
For comparison, available fossil fuel resources are about
5000 GtC

27. MH release and ocean warming
MH release leads to increased GHG forcing (CH4 and its oxidation product CO2) and warmer climate
Warmer climate promotes the release of more MH as the ocean is warmed further
Warming in the ocean leads to release of MH in ocean sediment
Dickens 2003, Earth and Planetary Science Letters

28. DCESS Earth System Model
Sun
Atmosphere
Ocean
Land Biosphere
Lithosphere
Ocean Sediment
CH4 Hydrate