Yale Environment 360 discusses why ‘Carbon-Cycle Feedbacks’ could drive temperatures even higher. New research indicates that parts of the Amazon and other tropical forests are now emitting more CO2 than they absorb. Some scientists are concerned this development, which is not yet incorporated into climate models, could put the temperature goals set by the Paris Agreement out of reach.
It is not often you meet a scientist breathless with excitement about their new findings. But it happened to me last September at the National Institute for Space Research in the Brazilian research city of Sao Jose dos Campos. Atmospheric chemist Luciana Gatti was rushing to tell her colleagues the result of her latest analysis of carbon dioxide emissions from the Amazon rainforest, which she had completed that morning.
For a decade, her team had been sampling the air from sensors on aircraft flying over the world’s largest rainforest. Their collating of recent results showed that, perhaps for the first time in thousands of years, a large part of the Amazon had switched from absorbing CO2 from the air, damping down global warming, to being a “source” of the greenhouse gas and thus speeding up warming.
“We have hit a tipping point,” Gatti almost shouted, caught between elation at her discovery and anguish at the consequences.
One recent study in northern Canada found thawing had reached depths “already exceeding those projected to occur by 2090.”