Wind born sediment also transports billions of tons annually, most prominent in Saharan dust, but thought to be substantially less than rivers; again, variance of year to year and human impacts of land use remain unquantified on this data.
The passage discusses wind-borne sediment's contribution to annual transportation, highlighting Saharan dust as a major contributor. It acknowledges that this amount is less than rivers but emphasizes the uncertainty surrounding its exact magnitude due to factors like weather patterns and human land use changes.