Amazon nears 'tipping point' where rainforest could transform into savanna

If deforestation continues, the Amazon rainforest could reach a critical tipping point where most of it transforms into a dry savanna, a new study warns. 

The study, published Monday (March 7) in the journal Nature Climate Change, suggests that more than 75% of the rainforest has steadily lost "resilience" since the 2000s, meaning those portions of the rainforest now can't recover as easily from disturbances, such as droughts and wildfires. Regions of the rainforest that show the most profound losses in resilience are located near farms, urban areas and areas used for logging, Inside Climate News reported.  

Climate change, rampant deforestation and burnings conducted for agriculture and ranching have left the Amazon far warmer and drier than in decades past, and since 2000, the region has endured three major droughts, The New York Times reported. 

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By examining satellite images taken between 1991 and 2016, the researchers determined how long the rainforest took to bounce back after such events, The Guardian reported. The researchers determined that, since the turn of the 21st century, the rainforest has been taking longer and longer to recover biomass, meaning the mass of living trees and other vegetation, after droughts and fires.  

"That lack of resilience shows that, indeed, there is only so much of a beating that this forest can take," Paulo Brando, a tropical ecologist at the University of California, Irvine who was not involved in the study, told The New York Times. 

The new study adds to existing evidence that the world's largest rainforest is hurtling toward a tipping point, beyond which large swaths of the forest could suddenly die off. The study cannot pinpoint when this tipping point might be reached, but the forest could hit it within decades, the study authors told Inside Climate News. 

If the rainforests surpasses this tipping point, the ecosystem could swiftly change into a vast savanna, unleashing tens of billions of tons of carbon dioxide during the transformation, The Guardian reported.

That said, some scientists don't agree with the use of the term "tipping point" in this context, according to Inside Climate News. 

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"It's sort of a mischaracterization that the scientists are certain that the Amazon is going to die" and that, in a snap, the whole forest could suddenly be lost, Scott Denning, a climate scientist at Colorado State University, told Inside Climate News. While Denning doesn't agree with this description of the situation, he said there's ample evidence that large portions of the forest are in rapid decline, particularly along the southern and eastern margins that have been ravaged by deforestation.

"It's not bouncing back. It's letting carbon out. It's drying out. It's dying," he said.

At this point, can anything be done to prevent the Amazon rainforest from turning into the Amazon savanna? Experts say there is.

"These systems are highly resilient, and the fact that we have reduced resilience doesn't mean that it has lost all its resilience," Brando told the Times. "If you leave them alone for a little bit, they come back super strongly."

But it requires key steps to be taken, experts said.

"We have to get to zero deforestation, zero forest degradation," Carlos Nobre, a senior scientist at the National Institute of Amazonian Research in Brazil, who was not involved in the study, told the Times. "We still have a chance to save the forest."

Originally published on Live Science.