As the world’s largest rainforest, the Amazon plays a crucial role in keeping our planet’s carbon-dioxide levels in check. Plants and trees take in carbon dioxide and release oxygen back into the air in their process of photosynthesis.
This is why the Amazon, which covers 2.1 million square miles, is often referred to as the “lungs of the planet”: The forest produces 20 percent of the oxygen in our planet’s atmosphere.
Typically, the Amazonian dry season runs from July to October, peaking in late September. Wetter weather during the rest of the year minimizes the risk of fires at other times But during the dry season, blazes can spark from natural sources, like lightning strikes. Farmers and loggers also purposefully set fire to the rainforest to clear swaths of the Amazon for industrial or agricultural use.
The fires raging in the Amazon now have widespread effects on the rest of Brazil. The smoke plumes from the blazes spread from the state of Amazonas to the nearby states of Pará and Mato Grosso, and even blotted out the sun in São Paulo – a city more than 2,000 miles (3,200 kilometers) away.