A study carried out over the last thirty years in the Amazon , published today in the journal Science , reveals that the world's largest tropical forest is extremely sensitive to drought.
In normal years, the Amazon absorbs around 2 trillion tons of carbon dioxide . Research by 68 scientists from 13 countries shows that for at least 25 years this tropical forest acted as a major carbon sink , absorbing a fifth of global fossil fuel emissions. But in 2005 an intense and unusual drought reversed the process, causing a loss of more than 3 trillion tons. The total impact of the drought, an extra 5 trillion tons of carbon dioxide in the atmosphere, exceeds the annual emissions of Europe and Japan combined.
"For years, the Amazon has been helping to slow down climate change. But relying on this subsidy from nature is extremely dangerous," warns Oliver Phillips, a professor at the University of Leeds and lead author of the research. If the droughts in the Amazon are repeated, they would accelerate global warming. "To really stabilize our climate, deeper cuts in emissions will be needed," concludes Philips.
