Expansion of the world’s deserts due to vegetation-albedo feedback under global warming

[1] Many subtropical regions are expected to become drier due to climate change. This will lead to reduced vegetation which may in turn amplify the initial drying. Using a coupled atmosphere-ocean-land model with a dynamic vegetation component that predicts surface albedo change, here we simulate the climate change from 1901 to 2099 with CO2 and other forcings. In a standard IPCC-style simulation, the model simulated an increase in the world’s ‘warm desert’ area of 2.5 million km or 10% at the end of the 21st century. In a more realistic simulation where the vegetation-albedo feedback was allowed to interact, the ‘warm desert’ area expands by 8.5 million km or 34%. This occurs mostly as an expansion of the world’s major subtropical deserts such as the Sahara, the Kalahari, the Gobi, and the Great Sandy Desert. It is suggested that vegetation-albedo feedback should be fully included in IPCC future climate projections. Citation: Zeng, N., and J. Yoon (2009), Expansion of the world’s deserts due to vegetationalbedo feedback under global warming, Geophys. Res. Lett., 36, L17401, doi:10.1029/2009GL039699.