(Paris) A significant part of the Amazon rainforest, a crucial climate regulator and valuable reserve of biodiversity, could reach “a breaking point” by 2050 due to drought, fires and deforestation, warns a published study Wednesday.
“Between 10 and 47%” of the Amazon’s surface “will be exposed to cumulative disturbances likely to trigger unexpected ecosystem transitions and exacerbate regional climate change,” estimates the study published in the journal Nature by an international group of around twenty researchers.
Under the pressure of “hotter temperatures”, “extreme droughts”, “deforestation”, and “erosion”, up to half of the Amazon would thus reach a “breaking point” or “tipping point”, leading the forest into a vicious circle synonymous with the potential collapse of ecosystems.
To arrive at this observation, Bernardo Flores and his colleagues analyzed five critical factors: global warming, annual precipitation, the intensity of the seasonality of precipitation, the length of the dry season and deforestation.
However, the Amazon is home to “10% of the planet’s biodiversity”, stores a “quantity of carbon equivalent to 15 to 20 years of emissions” from humanity and produces a “net cooling effect which contributes to stabilizing the climate of the planet,” recalls the study.
The study identifies three trajectories of permanent evolution of the forest: it could become in places degraded forests, with fewer species, more lianas and bamboo, or open forests, with smaller trees interspersed with grasses. invasive, or even a form of savannah.
From being a “carbon sink”, the Amazon risks becoming an “emitting source”, scientists fear.
“We may be closer to this breaking point than we previously thought,” said lead author Bernardo Flores of Santa Catarina University in Brazil.
The study highlights three avenues for remedy: the global reduction of greenhouse gas emissions, the end of deforestation and the restoration of degraded territories.
To arrive at this observation, scientists analyzed the effect of five critical factors: global warming, annual precipitation, the intensity of the rainy season, the duration of the dry season and deforestation.
The researchers relied on paleontological records (covering around 65 million years), climate models and observational data collected since the 1980s, such as satellite observations of the spread of forest fires, the coverage trees and deforestation.
Their findings complement those of the World Weather Attribution Network, which estimated in January that climate change has made the devastating drought that hits the Amazon in 2023 30 times more likely.