HR: 14:15h
AN: B33A-02    [Abstracts]
TI: Combined effects of climate change and forest clearing on the Amazon vegetation: Projections for 2080-2100
AU: * Cook, K H
EM: khc6@cornell.edu
AF: Cornell University, Department of Earth and Atmospheric Sciences 3114 Snee Hall, Ithaca, NY 14853, United States
AU: Vizy, E K
EM: ekv3@cornell.edu
AF: Cornell University, Department of Earth and Atmospheric Sciences 3114 Snee Hall, Ithaca, NY 14853, United States
AB: A regional climate model with resolution of 60 km coupled with a potential vegetation model is used to simulate future vegetation distributions over South America. The coupled model, which produces an accurate representation of today's climate and vegetation, is forced with increasing atmospheric CO2 concentrations, sea surface temperature from a global model, and scenarios of future land use practices to predict climate and vegetation distributions for the last 2 decades of the 21st century. When only climate change is considered, under a business-as-usual scenario for global emissions, the extent of the Amazon rainforest is reduced by about 70 per cent by the end of this century, and the shrubland (caatinga) vegetation of Brazil's Nordeste region spreads westward and southward. Reductions in annual mean precipitation are widespread and rainfall becomes insufficient to support the rainforest in these regions, but some areas receive more precipitation. The length of the dry season increases in the central and southern Amazon in association with changes in the large-scale tropical circulation. Without this change in seasonality, local refugia of Amazon vegetation would be preserved and the retreat of the rainforest would be somewhat less extensive. Including various projections of future land use practices in addition to climate change may accelerate the unrecoverable demise of the rainforest and feedback to modify climate on regional space scales. The portions of the rainforest that are most vulnerable to climate change are the same as those that are under the most pressure from human activity, presenting a remarkable competition.
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3322 Land/atmosphere interactions (1218, 1631, 1843)
DE: 3355 Regional modeling
DE: 3374 Tropical meteorology
SC: Biogeosciences [B]
MN: 2007 Joint Assembly