More than a third of the Amazon rainforest may have been degraded by human activity and drought, according to a scientific study unveiled Thursday in the journal Science, leading to calls for legislation to protect this vital ecosystem in danger.
The damage inflicted on this forest, which covers nine countries, is significantly greater than that which had been observed previously, indicated the researchers, notably from the Brazilian university Universidade Estadual de Campinas.
In their study, they analyzed the consequences of fires, logging, drought and changes to forest edge habitats — what they call edge effects.
Excluding drought, these phenomena have degraded at least 5.5% of the rest of the forests that make up the Amazon ecosystem, or 364,748 square kilometers, between 2001 and 2018, according to the study.
When the effects of drought are included, the deteriorated area then represents 2.5 million square kilometers, or 38% of the rest of the forests that make up the Amazon ecosystem.
“Extreme drought has become increasingly common in the Amazon due to changing land use practices and human-induced climate change affecting tree mortality, the number of fires and emissions. of carbon in the atmosphere,” the scientists said.
“Forest fires have intensified during the drought years,” they added, warning of the dangers of “large fires” in the future.
Scientists from Lafayette University in the US state of Louisiana and other institutions are calling for action, in a separate study of the impact of human activity on the Amazon ecosystem, also published in the journal Science.
“The changes are happening far too fast for Amazon species, populations and ecosystems to adapt,” they argued.
“The laws to avoid the worst consequences are known and must be enacted immediately. »
“To lose the Amazon is to lose the biosphere, and failure to act is at our peril,” the scientists concluded.