Fires on peatlands, which are carbon-rich, can almost double global fire-driven carbon emissions. Researchers found that despite accounting for only a quarter of the total UK land area that burns each year, dwarfed by moor and heathland, peatland fires have caused up to 90% of annual UK fire-driven carbon emissions since 2001 – with emissions spikes in particularly dry years.
Peat only burns when it’s hot and dry enough - conditions that are occurring more often with climate change. The peatlands of Saddleworth Moor in the Peak District, and Flow Country in northern Scotland, have both been affected by huge wildfires in recent years.
The researchers say land-managers can play an important role in helping to achieve Net Zero climate goals by keeping peatlands wet. This will reduce the likelihood of intense fires and their associated high carbon emissions.
Unlike heather moorland which takes up to twenty years to regrow after a fire, burnt peatland can take centuries to reaccumulate. The loss of this valuable carbon store makes the increasing wildfire frequency on peatlands a real cause for concern.
The findings, which are broadly relevant to peatlands in temperate climates, were published in the journal Environmental Research Letters.
“We found that peatland fires are responsible for a disproportionately large amount of the carbon emissions caused by UK wildfires, which we project will increase even more with climate change,” said Dr Adam Pellegrini in the University of Cambridge’s Department of Plant Sciences, senior author of the study.
He added: “Peatland reaccumulates lost carbon so slowly as it recovers after a wildfire that this process is limited for climate change mitigation. We need to focus on preventing that peat from burning in the first place, by re-wetting peatlands.”
The researchers found that the UK’s ‘fire season’ - when fires occur on natural land - has lengthened dramatically since 2011, from between one and four months in the years 2011-2016 to between six and nine months in the years 2017-2021. The change is particularly marked in Scotland, where almost half of all UK fires occur.
Nine percent of the UK is covered by peatland, which in a healthy condition removes over three million tonnes of carbon dioxide from the atmosphere per year.
Over 20 years #
To get their results, the researchers mapped all UK wildfires over a period of 20 years – assessing where they burn, how much carbon they emit, and how climate change is affecting fires. This involved combining data on fire locations, vegetation type and carbon content, soil moisture, and peat depth. Using UK Met Office data, the also team used simulated climate conditions to predict how wildfires in the UK will change in the future.
The study only considered land where wildfires have occurred in the past, and did not consider the future increases in burned area that are likely to occur with hotter, drier UK summers.
Rewetting peatlands to protecting the carbon they store will require land managers to be incentivised – the researchers say this won’t be easy, but the impact could be big.
“Buffering the UK’s peatlands against really hot, dry summers is a great way to reduce carbon emissions as part of our goal to reach net zero. Humans are capable of incredible things when we’re incentivised to do them,” said Pellegrini.
- The paper Spikes in UK wildfire emissions driven by peatland fires in dry years was published in Environmental Research Letters. Authors: Sarah J Baker, Matthew C Perry, Richard A Betts, Johanna Schoenecker & Adam F A Pellegrini.
Citation #
Spikes in UK wildfire emissions driven by peatland fires in dry years Sarah J Baker*, Matthew C Perry, Richard A Betts, Johanna Schoenecker and Adam F A Pellegrini*
Published 21 February 2025 • © 2025 The Author(s). Published by IOP Publishing Ltd Environmental Research Letters, Volume 20, Number 3 Citation Sarah J Baker et al 2025 Environ. Res. Lett. 20 034028 DOI 10.1088/1748-9326/adafc6
Funding #
Wellcome Trust, Isaac Newton Trust, UK Research and Innovation