- More than four million hectares of protected tropical forest - an area twice the size of Wales - has been destroyed by wildfires since 2001, according to the most detailed global assessment of its kind
- The rate of destruction inside protected areas is around nine times higher since 2016
- Protected status does reduce the chances of wildfires in most of the regions studied, but does not shield forests from the worldwide trend of worsening wildfire activity
- Researchers from the University of Sheffield say protected area planning must now factor in future wildfire risk if these measures are to remain effective as the impact of climate change intensifies
Over four million hectares of protected tropical forest - an area double the size of Wales - have been lost to wildfires since 2001.
Accelerating at an alarming rate, this destruction threatens sanctuaries once thought safe, according to a new University of Sheffield study.
, published in the journal Global Change Biology, is the first to assess in detail how much protected tropical forest has been lost to wildfires worldwide, and whether protected status actually reduces the risk of forests burning.
Researchers combined satellite wildfire data with maps of more than 9,700 protected areas across the tropics, tracking forest losses between 2001 and 2024.
They found that wildfire-driven destruction of protected tropical forests is not only substantial, but accelerating. The annual area burned inside protected areas has been roughly nine times higher since 2016 compared to previous years, with nearly a third of all 24-year losses occurring in 2024 alone.
The vast majority of the destruction - around 89 per cent - occurred in the tropical Americas, particularly in Brazil, which alone accounted for almost two-thirds of global losses. Bolivia and Indonesia also recorded substantial losses.
To test whether protection actually makes a difference, the researchers compared protected forest plots with very similar unprotected plots nearby, matched for factors known to influence wildfire risk, such as temperature, rainfall, how many people live in the area, and how much forest surrounds it. This allowed them to isolate the effect of protection itself, rather than other factors that might explain why some forests burn and others don’t.
The results were mixed but broadly encouraging: protected areas were less likely to burn than comparable unprotected forest in around half of all plots studied in the Americas, rising to around seven in ten plots in Africa. However, when the researchers looked at how wildfire activity has changed over time, they found protected and unprotected forests were following almost identical trends, meaning that as wildfire activity worsens across a region, protected areas are being swept up in that increase just as much as unprotected land.
Christopher Bousfield, Research Fellow at the University of Sheffield, said: “Protected areas help reduce wildfire risk, but they offer no guarantee of safety as climate change intensifies. Because most tropical fires are human-caused, safeguarding these forests requires active collaboration with local communities and landowners to prevent both deliberate land-clearing fires and accidental escapes into protected regions.â€
The researchers emphasise that protected areas are still one of our best tools for saving tropical forests, wildlife, and stored carbon. However, rather than treating wildfires as a separate issue, park planners must now build fire prevention directly into their conservation plans - especially as climate change and extreme weather events like El Niño make fires more frequent and intense.
Oscar Morton, Research Fellow at the University of Sheffield, said: “Protected areas have undoubtedly shielded tropical forests from fire over the past two decades. But they aren't immune to the broader climate crisis. To keep saving these ecosystems, we must tackle the root causes of increasing forest flammability - starting with climate change - and ensure fire risk is a core part of how we plan future reserves.â€
The study draws on high-resolution satellite data capable of detecting forest loss at a 30-metre resolution, allowing researchers to distinguish stand destroying from smaller, lower-intensity fires that can damage and degrade but do not necessarily destroy forest. Because of this, the researchers say their figures are likely to be a conservative estimate of the true scale of fire damage in protected tropical forest.