Changes in desert area due to humans have important implications from a local, regional
to global level. Here we focus on the latter in order to better understand estimated
changes in desert dust aerosols and the associated iron deposition into oceans. Using 17
model simulations from the World Climate Research Programme’s Coupled Model
Intercomparison Project phase 3 multi-model dataset and the BIOME4 equilibrium
vegetation model we estimate changes in desert dust source areas due to climate change
and carbon dioxide fertilization. If we assume no carbon dioxide fertilization, the mean
of the model predictions is that desert areas expand from the 1880s to the 2080s, due to
increased aridity. If we allow for carbon dioxide fertilization, the desert areas become
smaller. Thus better understanding carbon dioxide fertilization is important for
predicting desert response to climate. There is substantial spread in the model simulation
predictions for regional and global averages.

Last Updated: 2007-09-06