The world's subtropical deserts could expand up to 34 per cent by the end of the century, according to a new study. More moderate estimates suggest at most a 10-per-cent increase in desert area by 2100.
Ning Zeng and Jinho Yoon of the University of Maryland used an advanced model of world vegetation to simulate the continued expansion of deserts. Unlike more traditional models, theirs was specifically tuned to capture changes in albedo — the reflectivity of the land surface — triggered by desertification. Factoring albedo into their simulations increased desert expansion by three-fold, Zeng and Yoon found. They suggest that a decline in moisture at the desert edge increases the reflection of light from the land surface, which reduces the amount of heat absorbed. This in turn leads to large-scale changes in air circulation that further reduce precipitation at the desert's margins. The Sahara, Gobi, Kalahari and Great Sandy deserts are at greatest risk of expansion, conclude the authors.
They urge the Intergovernmental Panel on Climate Change to include feedbacks, such as those from albedo, in future modelling efforts to provide a more robust estimate of future desertification.
Rights and permissions
About this article
Cite this article
Newton, A. Expanding sands. Nature Clim Change 1, 100 (2009). https://doi.org/10.1038/climate.2009.84
Published:
Issue Date:
DOI: https://doi.org/10.1038/climate.2009.84
