We really don't know dust, at all

African dust keeps Amazon blooming : Nature News

But what about changes in precipitation, which could have an effect on the amount of dust produced?

Unfortunately, even the latest climate models can't agree on whether that part of Africa will get wetter or drier, says Prospero. "If it becomes drier, we can expect more dust."
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Dust in the atmosphere, or the lack of it, may have even wider implications. It increases the amount of sunlight reflecting off Earth into space, potentially offsetting global warming. It could also affect cloud formation, and even tropical storms. "It gets pretty complicated," says Prospero. "One of the primary areas of [global climate] research today is understanding the global cycle of dust."