Regional variability in the terrestrial carbon-cycle response to global warming in the 21st century: Simulation analysis with AOGCM-based climate projections

Abstract

Regional variability in the carbon-cycle response of terrestrial ecosystems to global warming was simulated with a spatially explicit, process-based model (Sim-CYCLE), and analyzed for 22 regions worldwide. The terrestrial net flux of carbon dioxide (CO2) during the period 2001-2099, was globally simulated on the basis of greenhouse gas emission scenarios (IPCC-SRES), and climate projections by coupled atmosphere-ocean general circulation models (AOGCMs). Most terrestrial ecosystems acted as net carbon sinks but with different magnitudes among the experiments (globally, 24 to 286 Pg C). Substantial inter-regional variability was found in terrestrial carbon-cycle response, because of differences in biome distributions and climate-change regimes. Moreover, among the experiments using the same CO2 scenario, but different AOGCM climate projections, inconsistent results were obtained in the Amazon basin, Africa, Australia, and northern Asia, indicating the need for further research.