A third of the Amazon rainforest has been “degraded” by humans and drought.

A scientific study published Thursday in the journal Science found that a third of the Amazon rainforest may be degraded by human activity and drought, prompting legislation to protect this vital ecosystem at risk.

The damage to these forests, which spans nine countries, is significantly greater than previously observed, noted researchers, notably from the Brazilian university Universitat Estadual de Campinas.

In their study, they analyzed the effects of fire, logging, drought, and changes in forest edge habitats—what they call edge effects.

Excluding drought, these events have degraded at least 5.5%, or 364,748 square kilometers, of the other forests that make up the Amazon ecosystem between 2001 and 2018, the study says.

When the effects of drought are included, the degraded area is 2.5 million square kilometers or 38% of the other forests that make up the Amazon ecosystem.

“Land-use practices and human-induced climate change in the Amazon are affecting the number of tree deaths, fires, and atmospheric carbon emissions, as severe droughts have become increasingly common in the Amazon,” the scientists said.

“Forest fires have intensified during periods of drought,” they warned of the dangers of “larger fires” in the future.

Scientists from Lafayette University in the US state of Louisiana and other institutions have called for action in a separate study on the impact of human activities on the Amazon ecosystem, also published in the journal Science.

“Changes are happening too fast to alter Amazon species, populations and ecosystems,” they argued.

“Laws are known to avoid dire consequences, and they should be enacted immediately. »

“Losing the Amazon means losing the biosphere, and failure to act is at our peril,” the scientists concluded.