View article

The possible responses of ecosystem processes to rising atmospheric CO₂ concentration and climate change are illustrated using six dynamic global vegetation models that explicitly represent the interactions of ecosystem carbon and water exchanges with vegetation dynamics. The models are driven by the IPCC IS92a scenario of rising CO₂ (Wigley et al. 1991), and by climate changes resulting from effective CO₂ concentrations corresponding to IS92a, simulated by the coupled ocean atmosphere model HadCM2‐SUL. Simulations with changing CO₂ alone show a widely distributed terrestrial carbon sink of 1.4–3.8 Pg C y⁻¹ during the 1990s, rising to 3.7–8.6 Pg C y⁻¹ a century later. Simulations including climate change show a reduced sink both today (0.6–3.0 Pg C y⁻¹) and a century later (0.3–6.6 Pg C y⁻¹) as a result of the impacts of climate change on NEP of tropical and southern hemisphere …