How The Fires In The Amazon Rainforest Will Impact The Global Ecosystem

AUDIE CORNISH, HOST:

Ecologist Dan Nepstad has studied the Amazon for more than 30 years. He explained to me why it's hard to know the true extent of these fires.

DAN NEPSTAD: In an intact Amazon forest - a virgin forest - if it's a really dry year and the fire gets going, it's shin-high. You can step over it, and that means it doesn't register a lot of heat, and the satellites don't pick up that as an act of fire. The best way to know if a forest...