The influence on climate forcing of mineral aerosols from disturbed soils

AEROSOLS influence the global radiation budget(1), and so changes in the atmospheric aerosol load due to either natural causes or human activity will contribute to climate change(2). A large fraction of the mass of tropospheric aerosol is wind-blown mineral dust, and its contribution to radiative forcing can be locally significant(3,22). Model calculations indicate that 50 +/- 20% of the total atmospheric dust mass originates from disturbed soils(4) (those affected by cultivation, deforestation, erosion, and frequent shifts in vegetation due to droughts and rains),Here, using a radiative transfer model embedded in a general circulation model, we find that dust from disturbed soils causes a decrease of the net surface radiation forcing of about 1 W m(-2), accompanied by increased atmospheric heating that may be a significant forcing of atmospheric dynamics. These findings suggest that mineral dust from disturbed soils needs to be included among the climate forcing factors that are influenced by human activities.