̽��ֱ�� of Cambridge - Met Office

UK peatland fires are supercharging carbon emissions as climate change causes hotter, drier summers

jg533 — Fri, 21 Feb 2025 07:00:52 +0000

More fires, taking hold over more months of the year, are causing more carbon to be released into the atmosphere as carbon dioxide.

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, wildfires that burn peat 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. ̽��ֱ��peatlands of Saddleworth Moor in the Peak District, and Flow Country in northern Scotland, have both been affected by huge wildfires in recent years.

Unlike heather moorland which takes up to twenty years to regrow after a fire, burnt peat can take centuries to reaccumulate. ̽��ֱ��loss of this valuable carbon store makes the increasing wildfire frequency on peatlands a real cause for concern.

̽��ֱ��researchers also calculated that carbon emissions from fires on UK peatland are likely to rise by at least 60% if the planet warms by 2^oC.

̽��ֱ��findings, which are broadly relevant to peatlands in temperate climates, are published today 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 ̽��ֱ�� 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.”

"We found that in dry years, peatland wildfires were able to burn into the peat and release significant quantities of carbon into the atmosphere. In particularly dry years this contributed up to 90% of the total wildfire-driven carbon emissions from the UK," said Dr Sarah Baker, lead author of the study which she conducted while at the ̽��ֱ�� of Cambridge. Baker is now based at the ̽��ֱ�� of Exeter.

̽��ֱ��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. ̽��ֱ��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.

̽��ֱ��researchers estimate 800,000 tonnes of carbon were emitted from fires on UK peatlands between 2001 and 2021. ̽��ֱ��2018 Saddleworth Moor fire emitted 24,000 tonnes of carbon, and the 2019 Flow Country fire emitted 96,000 tonnes of carbon from burning peat.

To get their results, the researchers mapped all UK wildfires over a period of 20 years – assessing where they burn, whether peat burned, 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 model outputs, the team also used simulated climate conditions to project how wildfires in the UK could change in the future.

̽��ֱ��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.

An average of 5,600 hectares of moor and heathland burns across the UK each year, compared to 2,500 hectares of peatland.

“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.

̽��ֱ��research was funded by Wellcome, the Isaac Newton Trust and UKRI.

Reference: Baker, S J et al: ‘Spikes in UK wildfire emissions driven by peatland fires in dry years.’ February 2025, Environmental Research Letters. DOI: 10.1088/1748-9326/adafc6.

A new study led by the ̽��ֱ�� of Cambridge has revealed that as our springs and summers get hotter and drier, the UK wildfire season is being stretched and intensified.

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

Adam Pellegrini

Sarah Baker

Fire on UK moorland

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Climate change will transform cooling effects of volcanic eruptions, study suggests

sc604 — Thu, 12 Aug 2021 08:50:37 +0000

Researchers have shown that human-caused climate change will have important consequences for how volcanic gases interact with the atmosphere.

Study identifies likely scenarios for global spread of devastating crop disease

fpjl2 — Mon, 25 Sep 2017 10:30:40 +0000

Stem rust, named for the blackening pustules that infect plant stems, caused devastating crop epidemics and famine for centuries before being tamed by fungicides and resistance genes.

Since the turn of the century, however, aggressive new strains have emerged – such as 'Ug99', first detected in Uganda in 1999 – that infect widely grown varieties of wheat. These diseases threaten to disperse trillions of pathogenic fungal spores on winds across countries and continents.

̽��ֱ��fear is that these airborne and highly virulent strains could spread from known sites to some of the world's most important 'breadbasket' regions, such as the Punjab in South Asia, where they have yet to be detected.

Now, a team of scientists of the ̽��ֱ�� of Cambridge, the UK Met Office and CIMMYT (International Maize and Wheat Improvement Centre) have adapted modelling systems previously used to forecast, ash dispersal from erupting volcanoes and radiation from nuclear accidents (NAME), to predict when and how Ug99 and other such strains are most likely to spread.

̽��ֱ��research, published today in the journal Nature Plants, quantifies for the first time the circumstances – routes, timings and outbreak sizes – under which dangerous strains of stem rust pose a threat from long-distance dispersal out of East Africa to the large wheat-producing areas in India and Pakistan.

̽��ֱ��results highlight the role of Yemen as a potential 'stepping stone' for the transmission of the disease between continents. ̽��ֱ��key scenario for disease spread is from Yemen directly to Pakistan or India. In case of a large outbreak in Eastern Yemen results indicate a 30% chance for transmission to occur.

Another important scenario for wheat rust spread is from Yemen through Middle Eastern countries, in particular Iran, to Central and South Asia. If Iran were to suffer a moderate outbreak of Ug99 – more than 1000 hectares – then spores would likely spread to Afghanistan, and from there potentially further to the northern plains of Pakistan and India. However, transmission along this route is restricted to a relatively short time-window in March and April, before wheat is typically harvested in South Asia.

"New races of wheat rust are threatening wheat worldwide, and we need to know which areas are at risk," said senior author Prof Chris Gilligan, from Cambridge's Department of Plant Sciences.

"From our work, we now believe that if we start to see Ug99 or other new wheat rust strains take hold in Yemen in early spring then action must be taken immediately to mitigate the risk of further spread."

However, the modelling work also offers some encouraging news: the airborne transmission of the disease from East African countries directly to South Asia is highly unlikely, with transmission events possible only on less than one day a year.

̽��ֱ��scientific team used field disease surveys from the International Maize and Wheat Improvement Centre and weather data from the UK Met Office as key input for the modelling framework.

"This research has allowed us to obtain the first quantitative estimates of long-term airborne spore transmission frequencies for different outbreak scenarios. We compiled risk assessments for pathogen dispersal from key disease locations to important wheat-producing countries. These assessments can effectively inform surveillance and control strategies," said Cambridge's Marcel Meyer, the study's first author.

̽��ֱ��team say their work, including 3-D spore dispersal animations and a catalogue of dispersal trends (indicating likely directions, frequencies, pathogen loads), provides new ways to raise awareness, communicate risks, and inform agricultural stakeholders.

Their modelling framework can be applied as a tool to analyse risks in case new disease strains should be uncovered in other geographic areas. This has already helped in estimating dispersal risks from sites of other diseases in Europe and Siberia. In ongoing work the team is developing an Early Warning System forecasting rust risk in Ethiopia, East Africa's largest wheat producing country.

" ̽��ֱ��combined expertise from plant sciences and atmospheric dispersion sciences has delivered ground breaking tools that highlight the risks, and support the management of the devastating potential of these diseases," said Dr Matthew Hort, co-author from the UK's Met Office.

New research reveals for the first time the most likely months and routes for the spread of new strains of airborne ‘wheat stem rust’ that may endanger global food security by ravaging wheat production across Africa, the Middle East, Asia and the wider world.

New races of wheat rust are threatening wheat worldwide, and we need to know which areas are at risk

Chris Gilligan

Left: CIMMYT. right: Matthew Hort.

Left: Wheat stem rust. Right: Network map of the atmospheric transmission of spores.

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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