The Amazon rainforest may be approaching a pivotal moment that could see the biologically rich and diverse ecosystem transformed into a grassy savannah.
The fate of the rainforest is crucial to the health of the planet because it is home to a unique array of plant and animal species, stores huge amounts of carbon, and strongly influences weather patterns. global weather.
Scientists say that about three-quarters of tropical forests are showing signs of “loss of resilience” – reduced resilience to disturbances such as drought, logging and fires. Their study, based on monthly observations of satellite data from the past 20 years, has mapped the biomass (organic material of the area) and the greenness of the forest to show how it has changed. in the face of fluctuating weather conditions.
The declining resilience since the early 2000s is a warning sign of an irreversible decline, the authors say. While it’s impossible to say exactly when the transition from rainforest to savannah might occur, once that becomes clear, it will be too late to stop.
Timothy M. Lenton, one of the authors of a new study and director: “It’s worth reminding ourselves that if it comes to a tipping point and we commit to losing the Amazon rainforest, then we will. receive critical feedback on global climate change. of the Global Systems Institute at the University of Exeter in the United Kingdom, spoke at a press conference.
We lose about 90 billion tons of carbon dioxide mainly in trees but also in soil (of the Amazon).
If the Amazon were no longer a rainforest, it wouldn’t store as much carbon.
Previous studies based on computer simulations have reached similar conclusions about the ecological point of no return of the Amazon rainforest – but the authors say their study, published in the journal Nature Nature Climate Change on Monday, using real-world observations.
Once we reach the cut-off point, the rainforest can disappear pretty quickly, the authors say. “My hunch, for what it’s worth, (that’s) that could happen in space decades,” Lenton said.
The study found that the loss of resilience was most severe in areas close to human activity as well as areas that received less rainfall. The study also notes that loss of resilience is not equivalent to loss of forest cover – meaning that tropical forests can be so close that they cannot return without obvious identifiable changes. .
Chantelle Burton, a senior climate scientist at the Met Office Hadley Center in the UK. says there is already a question mark about how the Amazon rainforest can cope with the challenges of climate change, changing land use and fires. She says the new study is “really important.”
Burton, who was not involved in the study, told the Center for Science Communication in London.
“Passing a tipping point like this will make it even harder to achieve our goal of Net Zero emissions globally because of the loss of the ‘free service’ provided by the Amazon carbon sink, which is now eliminating some of our emissions.”
Richard Allan, professor of climate science at the University of Reading, said the study was a “comprehensive and rigorous review of the durability of the Amazon forest.”
“It makes for an interesting conclusion that much of Amazon is showing signs that it may be approaching a point of irreversible decline; but because many satellite sensors are used to infer ‘lustfulness’ ‘ of vegetation, we need to be sure those data records are showing correct trends,” Allan was quoted as saying by the SMC statement.
“In any case, it is undeniable that human activities are waging a multi-pronged war of attrition against the natural world, although thankfully in this case the solutions are known. to: ending deforestation while rapidly and massively cutting greenhouse gas emissions.”