A new study has revealed that fire-scorched Amazon forests in Brazil remain significantly warmer for decades, severely weakening thei Environmental Research Letters by researchers from Columbia University’s Climate School, the study shows that fire-affected tropical forests stay, on average, 2.6°C warmer than untouched forests, with this elevated heat persisting for up to 30 years.
The research focused on southern and eastern Amazon regions and found that even after three decades, these forests showed only a 1.2°C temperature drop. “Burned forests exhibited substantially altered thermal regimes even after 15 years of recovery,” said lead author Savannah Cooley, now a NASA scientist. “Regeneration is much more at risk it’s slower or not happening at all.”
The team noted that fire damage across the canopy allows more sunlight to penetrate, leading to excessive heat accumulation. On some of the hottest recorded summer days, nearly 87% of leaves in scorched patches crossed critical temperature thresholds, impairing photosynthesis. In comparison only 72–74% of leaves in intact or logged forests hit this level under similar conditions.
This shift in microclimate disrupts natural regeneration. High and fluctuating temperatures hinder seed germination and sapling growth, making recovery nearly impossible without active human intervention. “Unlike savannahs or pine forests, Amazon trees are not adapted to fire. These ecosystems evolved in moist conditions where fires were historically rare,” Cooley explained.
The study also highlights a key climate concern: reduced carbon sequestration. Burned forests not only capture less carbon due to damaged biomass but also risk becoming long-term carbon sources rather than sinks. This challenges the common assumption that forest regrowth naturally offsets emissions over time.
Researchers urge policymakers and climate strategists to revise forest carbon models, accounting for long-term thermal stress in degraded landscapes. They also call for targeted restoration in fire-affected zones, rather than relying solely on natural recovery.
As fire seasons intensify under a warming climate, this study underscores the need to treat tropical forest fires not as temporary disturbances, but as events with enduring ecological and atmospheric consequences.