Transcript for Fires in Brazil, Bolivia consuming US-sized swaths of forest
Now, to alarming images coming in from the Amazon. Our team on the front lines of those devastating fires in the rain forest. The rain forest called the lungs of the planet, providing 20% of the world's oxygen. And tonight, these are the new images coming in, those catastrophic fires racing through the rain forest at record speed. Firefighters overwhelmed and so are the farmers, the workers, the people who live at the edge of the forest. And our Matt Gutman and our team right there with them. Reporter: Those fires roaring across Brazil and Bolivia tonight. Thousands of separate fires consuming swaths of forest the size of American states. That line of fire, as you see, stretching for dozens of miles, and it is so big that it's hard to tell if it's a single fire or hundreds of them. This afternoon, driving along the low live yan/brazilian border, we saw it up-close. Dozens of miles of incinerated palm forests. This rancher said his name is geronimo. He said an airplane did come through here and made a drop, but it didn't do anything. We offered him a ride out, but he wanted to stay, insisting his cattle would come back. This is what the firefighters have been dealing with for weeks now, and you can see how it's torching those palm trees like matchsticks. But that fire charging. Those palm trees exploding. We quickly moved out. Going to try to move a little bit faster to get out of its way. Keep going! Keep going. Geronimo's farm disappearing. They have deployed 44,000 troops and C-130s loaded with thousands of gallons of water. And Bolivia has contracted this 747 super tanker. President trump has offered help and the G 7 today pledging $20 million to try to save the Amazon, which produces 20% of the Earth's oxygen. In the meantime, those fires continue their destruction. Not more than five minutes ago, we were right through here and this was lush jungle. Driving back to geronimo's farm, that landscape transformed. Fires still burning on the side of the road. Geronimo? Senor? But emerging through the smoke, there he was. As he surveyed his smoldering ranch, his face was etched with and then, just like he'd promised, his cows came trotting home. And David, we're told that no matter how much international assistance pours in here, it's not going to do much to stop these fires. The only thing that can put them down, we are told, is mother nature. David? All right, Matt Gutman reporting in tonight from Brazil. Thank you.
This transcript has been automatically generated and may not be 100% accurate.