The Guardian reports: The world’s tropical forests are so degraded they have become a source rather than a sink of carbon emissions, according to a new study that highlights the urgent need to protect and restore the Amazon and similar regions.

Researchers found that forest areas in South America, Africa and Asia – which have until recently played a key role in absorbing greenhouse gases – are now releasing 425 teragrams of carbon annually, which is more than all the traffic in the United States.

This is a far greater loss than previously thought and carries extra force because the data emerges from the most detailed examination of the topic ever undertaken. The authors say their findings – published in the journal Science on Thursday – should galvanise policymakers to take remedial action.

“This shows that we can’t just sit back. The forest is not doing what we thought it was doing,” said Alessandro Baccini, who is one of the leader authors of the research team from Woods Hole Research Center and Boston University. “As always, trees are removing carbon from the atmosphere, but the volume of the forest is no longer enough to compensate for the losses. The region is not a sink any more.” [Continue reading…]