Published
27 Apr 2026

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What Antonio and his fellow firefighters are witnessing on the ground has been backed up by a new study. An international team of researchers, led by the University of Cambridge, have found that the policies that helped reduce deforestation in the Brazilian Amazon over the past two decades have mostly failed to stop forest degradation: a slower and potentially more dangerous form of destruction. Their results are published in the Proceedings of the National Academy of Sciences.

Unlike deforestation, where whole areas of forests are cleared for farming, industry or infrastructure, a degraded forest still has trees standing. However, it has been so damaged by fire, illegal logging, fragmentation, droughts and over-hunting that it has lost much of its ecological value. The forest floor, stripped of shade and moisture, becomes a tinderbox.

“There’s still a forest there, but it’s so damaged that the carbon it once stored starts leaking, the animals have disappeared, and new grass species colonise the forest edges,” said lead author Federico Cammelli from Cambridge’s Department of Geography and the Conservation Research Institute. “Tropical forest fires are low intensity, flames often go undetected under the canopy, but after one or two years, trees die while standing, and the forest transforms into a cemetery of dead standing trees.”

Earlier research found that between 2001 and 2018, net carbon emissions from forest degradation in the Brazilian Amazon were comparable or even higher than those from deforestation itself. By 2050, degradation could affect the entire Brazilian Amazon, but it has barely featured in the policies meant to protect it.

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