Amazon drought 'severe' in 2010, raising warming fears
3 February 2011 Last updated at 23:12 GMT
Last year's drought in the Amazon raises concerns about the region's capacity to continue absorbing carbon dioxide, scientists say.
Researchers report in the journal Science that the 2010 drought was more wide-spread than in 2005 - the last big one - with more trees probably lost.
The BBC's David Shukman reports.