The Grand Challenge on Carbon Feedbacks in the Climate System will pursue the following objectives:

I. Process understanding on land:
  • quantification of the strength of the CO2 fertilization, photosynthesis and limitations from nitrogen cycle
  • quantification of gross carbon fluxes sensitivity to warming and variability (and changes in hydrology)
  • understanding of ecosystems vulnerability and risk of carbon loss
II. Process understanding in the ocean:
  • quantification of the strength of the Southern Ocean CO2 uptake 
  • the relative role of physical vs. biological processes in determining ocean carbon sink
  • understanding the origins of variability (from seasonal to decadal) of the ocean carbon sink 
  • relationship between anthropogenic carbon and heat uptake
III. Learning from the existing record:
  • observational frameworks 
  • model evaluation/benchmarking
  • developing new emerging constraints
  • from paleorecord to satellite data
IV. Towards improved projections:
  • improved feedback framework (water cycle, regional focus)
  • improved Earth System models 
  • ESM re-analysis (physics and biogeochemistry)