Why the Amazon rainforest is burning
30 December 2011 Last updated at 09:51 GMT
The Amazon is a wet jungle, and hence should not burn but over the last decade, vast areas of the rainforest have been lost to fire.
Fires, lit to clear neighbouring land for farming, have spread into the forest during the dry season. While in the past the jungle would keep wet even during these months, global climate change and deforestation has increased drought episodes in the Amazon forest, making it more vulnerable to fire.
Dan Nepstad is a world renowned ecologist and expert on the Amazon. He has set up controlled experiments to study how fire is affecting the Amazon, which he demonstrates here to Justin Rowlatt.