Transcript for Amazon rainforest on fire: ‘Lungs of the world’ in flames
Reporter: Firefighters no match for flames this ferocious and this intense. Igniting palm trees on the bolivian-brazilian border fueled by wind, flames leaping across the dry brush. It's shocking how far we've seen the fire move. 200 yards in the last five minutes alone. Fueled by this wind. We're going to try to move a little faster to get out of its way. Keep going. Geronimo, a rancher here, tells me a tanker dropped water on the fire nearby. It's no use. He says it's all going to be gone. There's nothing else to do. He's just going to wait for the fire to pass. As a cloud of smoke rears up behind his farm, we offer him a ride out. But he insists on staying, certain his cattle will come back. We escape just as geronimo's farm and the road are enveloped in impenetrable fire and smoke. Wow, that entire place where we were just minutes ago seems to be gone. Reporter: It's just one apocalyptic scene amidst a swarm of fires ravaging Brazil and its Amazon rainforest spilling out into Bolivia, Paraguay, and Peru. It's the scale of these fires that's absolutely huge. An unprecedented burn of a massive magnitude. We could be losing in certain areas as much as three soccer fields of jungle every single minute. Reporter: The collection of tens of thousands of blazes engulfing an area 2/3 the size of the continental united States. Fires burning from the equivalent of Detroit to los Angeles. The rainforests' verdant trees, lush landscapes, a biosphere teeming with life. The so-called lungs of the Earth. Much of it now choked in flames. We are talking about an estimated 10% of the world's global biodiversity. Well over 40,000 species. New ones being discovered every single day. That is all at risk. Reporter: Most of the fires are so remote it requires hacking through the nearly impenetrable terrain just to reach them. Going through this underbrush gives you a sense of why these fires are so hard to stop, because they're so very hard to get to. Reporter: Containing fires is a herculean effort, even for the best equipped countries. On the ground we see how ill prepared Brazil is for the task. A squad of just 30 firefighters are tasked with covering an area twice the size of New Jersey. The tools they have are pretty rudimentary, you can see. They have these -- they look like floor mats in cars. And they're using sticks to slap down the fire. Sometimes the men just kicking at the fire. There are no fire trucks, no hoses, no radios. They're actually calling out to each other. That's how they're communicating in the bush. Because there is no cell phone reception right here. And through that veil of flames this villager appears. He says his name is Jefferson. He tells us he was the one who first reported the fire, even started fighting the fires himself. He's showing us how he was putting out fires. Reporter: He said the fire burned the shirt right off his back, the ground scorching his feet. You've got to feel this stick. It is burning hot right now. That he was holding. Also he's got no shoes. He's burned off his -- his flip-flops are completely melted. But he stayed, as did those weary firefighters. The U.S. Government and other countries pledging assistance. An American supertanker, the world's largest firefighting airplane, flew from Colorado Springs to Bolivia to help contain the fires there. At first Brazilian president Jair bolsonaro accused without evidence Brazilian ngos of starting the fires. Bolsonaro's seeming lack of urgency around the fires igniting protests in Rio de Janeiro. But bolsonaro reversed course over the weekend, authorizing the deployment of 44,000 troops. Brazil's air force deploying c-130 tankers streaming over 3,000 gallons of water per drop. The ultimate question is whether or not Brazilian internal politics will win out over the well-being of the Amazon, an area that cleans our air, purifies our water, gives us water in many instances, and on top of that holds many of the key and important solutions to tomorrow's problems. Reporter: It is believed that many of the fires were started by farmers trying to clear land. Environmentalists say bolsonaro's seeming support for the development of the Amazon over environmental practices may have emboldened farmers to burn land. We've seen a dramatic increase in deforestation in the Amazon recently, and it is driven by humans and this is happening in part due to demand for food and other resources from the forest and exacerbated by the decline in the enforcement of laws. Reporter: The area of smoke from these fires is so large it is visible from space. Nasa releasing these images. A carbon monoxide plume hovering over the Amazon. It's a double whammy from a climate perspective. We're losing forests which are some of the best technology we have right now to slow climate trees suck carbon out of the atmosphere. At the same time as the forests burn we're releasing huge stores of carbon into the atmosphere. So it's definitely exacerbating the problem and making it that much harder to mitigate climate change. Reporter: The Amazon produces 20% of the Earth's oxygen and helps regulate the Earth's temperature. And Brazil is only at start of its dry season, which typically lasts until November. We need to remember that most of the Amazon is still intact. There's still a lot left worth fighting for. If your house is on fire and let's say your kitchen catches on fire, you're not going to say, oh, well, I lost the entire house because my kitchen's on fire. You're going to fight for every last bit of it. And that's exactly what we need to do. Reporter: We wait agonizing minutes for flames and smoke to subside. Then head back in to check on geronimo. This was lush jungle. It is now completely charred. And we're going back here to see if that farmer named geronimo is okay. Geronimo. Senor! He's right over there. He says this part of the land was spared. Largely because he cleared that brush. And then incredibly geronimo's cows came home. Just as he said they would. For "Nightline" I'm Matt Gutman along the brazilian-bolivian border.
This transcript has been automatically generated and may not be 100% accurate.