Amazon fires are rising threat to Brazil’s great rainforest

Smoke rises through the understory of an Amazon forest. Plants and animals in the rainforest evolved largely without fire, and so cannot easily adapt to cope with it. Image: By Paulo Brando

Brazil’s great rainforest is a reservoir of global richness. Its government has reduced that wealth and burned a resource.

LONDON, 9 September, 2021 − For at least 12,000 Amazon species, extinction has just got a little closer. In this century alone, more than 100,000 vital square kilometres of Brazil’s great rainforest have been damaged by fire.

In the course of that burning and degradation, up to 85% of all those Amazon plants and vertebrates already listed as threatened have lost precious habitat.

The Amazon basin is home to at least 40% of the planet’s remaining rainforest. It is a vital functioning part of the planetary climate machine. It is one of the world’s richest ecosystems: a tenth of all known species on the planet live under its canopy. In just one square kilometre of forest, there could be 1,000 species of tree.

And although Brazilian government policies since 2001 have slowed the rate at which forest habitat has been destroyed, since 2019 and a change of government this trend has been reversed, say 23 scientists in a new study for the journal Nature.

They generated maps of the region’s astonishing biodiversity and catalogued the ranges of 11,514 plant and 3,079 animal species. They then imposed on this map their satellite-based observations of fire and damage since 2001.

“Since the majority of fires in the Amazon are intentionally set by people, preventing them is largely within our control”

They calculated that in the last two decades, somewhere between 103,079 and 189,755 sq kms of rainforest have caught fire or been harmed by it. This adds up to somewhere between 2.2% and 4.1% of the total. They calculated that for every 10,000 sq kms of forest torched, somewhere between 27 and 37 different plants and two or three vertebrates must have been affected.

That adds up to an estimated total of between 12,064 and 12,801 plants and animals that have lost range and become increasingly threatened.

Since 1960, around 20% of the Amazon forest has been scorched and cleared. By 2050, Brazil’s great rainforest could have lost 40%. And the point the researchers make is that what happens to the forest is a matter for the people, and for the government of Brazil which notoriously in 2019 started to dismantle some of the region’s protection.

“We show how policy has had a direct and enormous influence on the pace at which biodiversity across the entire Amazon has been affected. Even with policies in place, which you can think of as a brake slowing the rate of deforestation, it’s like a car that keeps moving forward, just at a slower speed. But in 2019 it’s like the foot was let off the brake, causing it to accelerate again,” said Brian Enquist of the University of Arizona in the US, one of the authors.

Spiral of decline

“This is important in light of the fact that biodiversity goes hand in hand with ecosystem functioning. Species can become virtually extinct even before they lose their entire range of habitat.”

Researchers have addressed these themes before and warned repeatedly of the potential calamity already facing one of the planet’s most important ecosystems, as forest destruction drives climate change and climate change in turn begins to dry up what was once rainforest, to make it even more vulnerable and intensify climate change even further.

“Since the majority of fires in the Amazon are intentionally set by people, preventing them is largely within our control,” said Patrick Roehrdanz of Conservation International, another of the authors.

“One way is to recommit to strong anti-deforestation policies in Brazil, combined with incentives for a forest economy, and replicate them in other Amazonian countries.” − Climate News Network