The Amazon rainforest is reaching a point of no return due to climate change and could become an arid savannah within half a century, researchers warn Wednesday in a study published in the journal Nature Communications.
According to the same study, the coral reef in the Caribbean, another large ecosystem, could disappear in 15 years if it also passes through a point of no return.
Experts warn that these changes would have dramatic consequences for humans and other species that depend on these habitats.
In both cases, the causes of these changes are climatic changes caused by humanity due to environmental damage: deforestation in the case of the Amazon and ocean pollution and acidification in the coral barrier.
According to the work of UN climate experts (IPCC), 90% of corals in shallow waters will be condemned if global warming reached a temperature rise of 1.5 ° C compared to the pre-industrial period.
Experts warn that an increase of 2 ° C will mean the almost complete disappearance of the coral barrier and remember that the warming has already reached 1 ° C.
In relation to the Amazon, the tipping point is less clear, but scientists believe that the loss of 35% of the surface would cause it to disappear.
About 20% of the Amazon rainforest, which covers more than five million square kilometers spread across seven countries, has been cleared since 1970, mainly to cultivate soy, wood, palm oil, biofuels or livestock.
"Humanity must prepare for change much more quickly than expected," warned the study's lead author, Simon Willcock of the University of Bangor in Wales.
The arguments presented in the study by the scientists reflect that the Amazon ecosystem could collapse next year.
The forest fires that recently went out of control in the Amazon and Australia suggest that many ecosystems are "on the verge" of rupture, they say.
"If we don't act quickly, we may be about to lose one of the largest and most diverse tropical forests, which has evolved over 58 million years and on which tens of millions of people depend," he told the magazine Alexandre Antonelli, of the Royal Botanic Gardens , who did not participate in the study.
The researchers, who studied climate change in 40 natural regions of different sizes, stress that ecosystems can change quickly when subjected to stress.
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