The African contribution to the global climate-carbon cycle feedback of the 21st century.

Future climate change will have impact on global and regional terrestrial carbon balances. The fate of African tropical forests over the 21st century has been investigated through global coupled climate carbon cycle model simulations. Under the SRES- A2 socio-economic CO₂ emission scenario of the IPCC, and using the Institut Pierre Simon Laplace coupled ocean-terrestrial carbon cycle and climate model, IPSL-CM4- LOOP, we found that the warming over African ecosystems induces a reduction of net ecosystem productivity, making a 20% contribution to the global climate-carbon cycle positive feedback. However, the African rainforest ecosystem alone makes only a negligible contribution to the overall feedback, much smaller than the one arising from the Amazon forest. This is first because of the two times smaller area of forest in Africa, but also because of the relatively lower local land carbon cycle sensitivity to climate change. This beneficial role of African forests in mitigating future climate change should be taken into account when designing forest conservation policy. [ABSTRACT FROM AUTHOR]