More than one-third of the Amazon rainforest may have been degraded by human activity and drought, researchers say, as Brazilian President Lula da Silva urged his French counterpart to attend the upcoming summit of Amazon countries.
Most research into the Amazon's ecosystem has focused on the impact of deforestation. However, a process known as "degradation" is further contributing to the Amazon's demise.
A study published in the journal Science on Thursday found that 38 percent of what remains of the the world's largest rainforest has been degraded in some way by humans – much more than previously known.
Fire, timber extraction and edge effects degraded at least 5.5 percent (364,748 square kilometers) of the forest between 2001 and 2018.
Once the effects of drought are factored in, the degraded area increases to 2.5 million square kms, or 38 percent of the remaining forests.
"Extreme droughts have become increasingly frequent in the Amazon as land-use change and human-induced climate change progress, affecting tree mortality, fire incidence, and carbon emissions to the atmosphere," the researchers said.
Since forest fires intensify during drought years, they warned of "much larger megafires" in the future.
The researchers from Brazil's Universidade Estadual de Campinas and other institutions based their findings on satellite images and other data from 2001 to 2018.
'We fail to act at our peril'
In a separate study on the human impacts on the Amazon, researchers from the University of Louisiana Lafayette and elsewhere called for action.
"The Amazon is perched to transition rapidly from a largely natural to degraded and transformed landscape, under the combined pressures of regional deforestation and global climate change," they said.
"The changes are happening much too rapidly for Amazonian species, peoples, and ecosystems to respond adaptively."
They called for policies to prevent the worst outcomes to be enacted immediately.
"To fail the Amazon is to fail the biosphere, and we fail to act at our peril," they said.
Pledge to end deforestation
Brazil's new president, Luiz Inacio Lula da Silva, has pledged to end deforestation of the Amazon by 2030.
In a phone call to Emmanuel Macron on Thursday, he talked about the importance of France attending a summit of the eight countries of the Amazon forest that Brazil plans to host in the next few months
France is the only European country to share the biome, through its overseas territory of French Guiana.
Macron has meanwhile asked Brazil to attend its own "One Forest Summit" that France and Gabon will host in early March, according to the Brazilian statement.
Following their conversation, Macron said he had reaffirmed his determination to take action "for the climate, biodiversity, our forests and against hunger".