Question

What triggers droplet formation in clouds?

Answer 1

nucleation around suspended particulates (ie. dust)

Explanation:

for example, forest fires in the amazon give rise to increased suspended particulate matter in the atmosphere, which creates additional nucleation sites and premature rainfall - the rain doesn't get as far into the interior which results in "drought" (absence of sufficient rain) with the amazonian interior.

Slash and burn agriculture has broad implications to the region.