Fighting a fire in the Brazilian Amazon near Rio Pardo in 2019.Credit...Victor Moriyama for The New York Times
The Amazon is losing its ability to recover from disturbances like droughts and land-use changes, scientists reported Monday, adding to concern that the rainforest is approaching a critical threshold beyond which much of it will be replaced by grassland, with vast consequences for biodiversity and climate change.
The scientists said their research did not pinpoint when this threshold, which they described as a tipping point, might be reached.
“But it’s worth reminding ourselves that if it gets to that tipping point, that we commit to losing the Amazon rainforest, then we get a significant feedback to global climate change,” said one of the scientists, Tim Lenton, director of the Global Systems Institute at the University of Exeter in England.
Losing the rainforest could result in up to 90 billion tons of heat-trapping carbon dioxide getting put back into the atmosphere, he said, equivalent to several years of global emissions. That would make limiting global warming more difficult.
The scientists said their research did not pinpoint when this threshold, which they described as a tipping point, might be reached.
“But it’s worth reminding ourselves that if it gets to that tipping point, that we commit to losing the Amazon rainforest, then we get a significant feedback to global climate change,” said one of the scientists, Tim Lenton, director of the Global Systems Institute at the University of Exeter in England.
Losing the rainforest could result in up to 90 billion tons of heat-trapping carbon dioxide getting put back into the atmosphere, he said, equivalent to several years of global emissions. That would make limiting global warming more difficult.
Carlos Nobre, a senior scientist at the National Institute of Amazonian Research in Brazil and one of the first to sound alarm over the potential loss of the Amazon more than three decades ago, described the new study as “very compelling.”
“It raised my level of anxiety,” said Dr. Nobre, who was not involved in the research.
Covering more than two million square miles in Brazil and neighboring countries, the Amazon is the world’s largest rainforest, and serves a crucial role in mitigating climate change in most years by taking in more carbon dioxide from the atmosphere than it releases. In its diversity of plant and animal species, it is as rich as or richer than anywhere else on the planet. And it pumps so much moisture into the atmosphere that it can affect weather beyond South America.
No comments:
Post a Comment