Potential high-latitude vegetation feedbacks on CO2-induced climate change

We use a fully coupled climate-vegetation model to examine the potential ef fects of changes in vegetation cover on simulations of CO2-induced climate change. We find that vegetation feedbacks, acting mainly through changes in surface albedo, enhance greenhouse warming in the northern high latitudes during spring and summer months. In spring and summer, land surfaces north of 45 degrees N are warmed by 3.3 and 1.7 degrees C by a doubling of CO2 al one; vegetation feedbacks produce an additional warming of between 1.1-1.6 and 0.4-0.5 degrees C, respectively. In winter, however, vegetation feedbac ks appear to oppose the 5.6 degrees C radiative warming, particularly over Eurasia. These results demonstrate that vegetation feedbacks are potentiall y significant and must be included in assessments of anthropogenic climate change.