The Amazon wildfires this past year generated a brief flurry in the news and social media cycles and also a lot of misinformation. A new NASA study may help to clear things up a bit.
Over the last 50 years, the Amazon rain forest has been reduced by about 20 percent and this has coincided with an increasing frequency of drought. During hot weather, plants and trees of the Amazon pull in water from the soil through their roots and release water vapor through pores on their leaves into the atmosphere, where it cools the air and eventually forms clouds, which produce rain.
In this way, the rain forest is able to generate as much as 80% of its own rain, even during the dry season, but the shrinking forest is less efficient at generating rain, leading to increased drought, which further reduces the rain forest. More soot from the increasing wildfires absorbs an increasing amount of sunlight, adding another feedback to the changing system.