The Amazon rainforest is losing its ability to recover from disturbances like droughts, climate change, and destructive land use, with three-quarters of the forest showing signs of “resilience loss,” according to researchers.
To put the seriousness of the problem in perspective, young people today may see the Amazon rainforest shift into the Amazon savannah in their lifetimes. That’s the takeaway of an alarming new study in the peer-reviewed journal Nature Climate Change.
In the study, satellite imagery covering several decades was used. The information included remote sensing data that measures the amount of biomass in specific areas, as well as other parameters which correspond to their health.
Looking at what were once pristine areas of the forest, the researchers found that overall since 2000 these areas lost resilience. For example, it took increasingly longer for forested areas to regain their health after suffering in a drought,
The rainforest, one of the wettest on Earth, has experienced three droughts since 2000. Adding climate change, together with widespread deforestation and burning for agriculture and ranching,, and we now have a region that is dryer and warmer.
And at the rate the changes are going, the towering trees will soon be replaced by grassland, with vast consequences for biodiversity and climate change. Scientists can’t pinpoint the date this changeover – which they call a “tipping point” will happen.
Lead author Chris Boulton of the UK’s University of Exeter says it’s impossible to predict with certainty when the tipping point might happen, given the size and complexity of the Amazon. But once it does arrive, the rainforest as we know it is expected to disappear relatively quickly and morph into a grassy savannah.
“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.
“My hunch, for what it’s worth, (is that) it could happen in the space of decades,” Lenton.
Chantelle Burton, a senior climate scientist at the Met Office Hadley Centre in the UK, said that there had been a question mark over how the Amazon rainforest would stand up to the challenges of climate change, land-use change, and fires. She said this new study was “really important.”
“What this study does is offer some observational-based evidence for what is already happening to this significant carbon sink, and shows that human land-use and changes to weather and climate patterns are already driving an important change in the system,” Burton said.
