The current consensus is that up to half of the modern atmospheric dust load originates from anthropogenically‐disturbed soils. Here, we estimate the contribution to the atmospheric dust load from agricultural areas by calibrating a dust‐source model with emission indices derived from dust‐storm observations. Our results indicate that dust from agricultural areas contributes <10% to the global dust load. Analyses of future changes in dust emissions under several climate and land‐use scenarios suggest dust emissions may increase or decrease, but either way the effects of climate change will dominate dust emissions.

[1] The degree to which dust emissions are controlled by vegetation cover and geomorphic setting (specifically closed topographic depressions) was investigated using dust storm frequency (DSF) data based on visibility measurements from >2400 meteorological stations worldwide. Comparisons with distributions of vegetation types suggest that DSF is highest in desert/bare ground (median: 60-80 d/yr) and shrubland (median: 20-30 d/yr) regions, and comparatively low in grassland regions (median: 2 -4 d/yr). Average DSF is inversely correlated with leaf area index (an index of vegetation density) and net primary productivity. In nonforested regions, DSF increases as the fraction of closed topographic depressions increases, likely due to the accumulation of fine sediments in these areas. These findings support the importance of incorporating vegetation and geomorphic setting as explicit controls on emissions in global dust cycle models.

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