[gleglegle]

His explanation is misleading. These are man-made fires caused by massive deforestation. Sources:

https://www.bloomberg.com/graphics/2019-why-amazon-rainfores...

https://science.sciencemag.org/content/sci/361/6407/1108.ful...

https://www.washingtonpost.com/weather/2019/08/22/photos-her...