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Scientists comment on the wildfire situation in the UK.
Dr Becky Wagner, Atmospheric Chemist and Climate Scientist at the University of Sheffield, said:
“The recent heat waves and prolonged periods of hot and dry weather with little rainfall have resulted in vegetation becoming extremely dry, creating a fuel source for fires. In addition, recent windy conditions mean that once a fire starts, it can spread much more rapidly and become increasingly difficult to contain. Wildfires have become more frequent in the UK in recent years and this trend is expected to continue as climate change increases the likelihood of prolonged periods of hot and dry weather conditions.
“An important aspect to consider is the impact of wildfires on air quality. Wildfires produce large amounts of air pollutants, including fine particulate matter (PM2.5), which can be transported long distances from the fire itself. This means that areas far away from the fire can experience poor air quality, with potential health implications particularly for people with respiratory and cardiovascular conditions.
“This is something that we are seeing with the recent wildfires in Tintwistle/Dovestones area, where smoke has been transported into areas of Greater Manchester, leading to elevated PM2.5 concentrations, with areas exceeding air quality guideline values designed to protect public health.”
Dr Zak Campbell-Lochrie, Lecturer in Fire Science, Institute for Infrastructure and Environment, School of Engineering, University of Edinburgh, said:
“Sustained periods of hot and dry weather across the UK have provided the background conditions to enable the widespread wildfires reported over recent days. These hot and dry conditions lead to drier vegetation which is more susceptible to ignition and which can subsequently spread more rapidly, particularly when coupled with windier conditions.
“Stronger wind conditions promote faster wildfire spread by promoting the drying of vegetation, and, when aligned with the direction of fire spread, can also increase the rate of energy transferred by wildfire flame fronts to the unburnt fuel ahead of the fire front.
“As heatwave conditions continue in many parts of the UK, it is important to remember that wildfires in the UK are typically human-caused. Therefore, we all have a role to play in reducing the risk, by following warnings from fire and rescue services about the use of barbeques and open fires, and accessing natural areas responsibly.”
Dr Joe McNorton, Fire Scientist at the European Centre for Medium-Range Weather Forecasts (ECMWF), said:
“How long these current fires last depends on a combination of weather conditions, the available fuel, and suppression efforts. The most visible flames may be brought under control, but fires in areas such as Tintwistle Moor can continue smouldering underground for days or even weeks. These underground hotspots can then re-emerge when conditions become favourable for renewed spread.
“In a global wildfire context these fires are relatively small, but that does not mean they are without impact. In the UK, these fires are on the order of hundreds of hectares. To put this into context, the largest recorded wildfire in the UK was the Dava and Carrbridge fire in 2025, which burned over 11,000 hectares. At the European scale, wildfire events can be almost an order of magnitude larger again; for example, the Alexandroupolis wildfires in 2023 burned almost 100,000 hectares.
“The amount of smoke produced depends not only on the amount of vegetation burned, but also on the type of fuel and how completely it burns. More visible smoke is often associated with incomplete combustion, where more particles and gases are released. Smoke can remain over large areas because of atmospheric conditions. During stable conditions, with light winds and temperature inversions, smoke is not efficiently mixed upwards and can remain concentrated close to the surface.
“The particles contained within wildfire smoke scatter and absorb light, reducing visibility.
“Peat is different because it is not simply vegetation at the surface; it is a deep layer of partially decomposed organic material that can store large amounts of carbon. When peat dries out, it can burn slowly underground. These fires can appear extinguished at the surface but continue smouldering below, allowing them to re-emerge when conditions become favourable for spread. This appears to be what has happened with the Tintwistle Moor fire.
“There are several similarities with 2018, particularly the prolonged dry weather that created very dry fuels and allowed fires to persist, including fires that penetrated into deeper organic soils.
“This depends strongly on the ecosystem and the severity of the fire. Some grasslands can recover relatively quickly, over months to years, whereas peatlands and moorlands can take much longer because the carbon-rich soils and habitats develop over decades to thousands of years.
“The ecological impact depends not only on the area burned but also on the intensity of burning and how frequently fires occur. There is growing evidence that extreme wildfire events are occurring in regions where such fire behaviour has historically been uncommon. These ecosystems may not have the resilience or recovery mechanisms needed to cope with fires of this frequency and intensity, so the long-term impacts remain an active area of research.
“The conditions that allow wildfires to become severe develop over different timescales. A wet winter and spring can promote vegetation growth and delay the drying of existing vegetation. Normally, the dry dead fuels that accumulate over winter can drive many early-season fires, but prolonged wet conditions can delay this process. If this is then followed by a rapid transition to hot, dry weather, both abundant cured dead fuels and increasingly stressed live vegetation can contribute to elevated fire danger later in the season, a process sometimes described as a hydroclimatic rebound.
“Over shorter timescales, dry atmospheric conditions can rapidly remove moisture from vegetation and increase fire danger. Once a fire starts, wind speed and gusts become critical factors in controlling how quickly it spreads.”
Dr Thomas Smith, Associate Professor in Environmental Geography, London School of Economics and Political Science (LSE), said:
“It is difficult to predict exactly how long individual fires will continue, but current fire weather conditions suggest that wildfire risk will remain very high across parts of northern England for several more days. Increasing relative humidity later in the week may help reduce some of the extreme fire behaviour seen earlier, but if fires have become established in peat soils they can continue to smoulder for days or even weeks after the visible flames have disappeared.
“If peat is involved, it can explain the extraordinary amount of smoke being produced. Unlike grasses or shrubs, peat burns through a slow smouldering process rather than with large flames. Smouldering is an inefficient form of combustion that produces large amounts of smoke, fine particulate matter and other pollutants.
“The current weather pattern is also likely contributing. High pressure systems, like those driving the current heatwave conditions, often create stable atmospheric conditions with little vertical mixing of the air. In some situations, a temperature inversion develops, trapping smoke close to the ground rather than allowing it to disperse. This can lead to persistent smoke over large areas, reducing visibility and affecting air quality many kilometres away from the fire itself.
“Peat fires are particularly challenging because they can continue burning beneath the surface long after flames have been extinguished. Heat can remain trapped underground for days or even weeks before re-emerging when conditions become favourable. This is why peat fires can appear to have been extinguished before reigniting.
“Unlike grass fires, which usually burn quickly across the surface, peat acts more like a slowly smouldering fuel. It burns progressively through the organic material beneath the ground, making it much harder to detect, suppress and extinguish completely.
“The UK has experienced significant wildfire seasons before, including the major moorland fires of 2018 and the unprecedented ‘firewave’ during the July 2022 heatwave. Recent events suggest that the weather conditions capable of producing these large wildfire episodes are becoming more frequent.
“One of the defining characteristics of a firewave is not simply the size of an individual fire, but the number of significant fires occurring simultaneously across the country. That places considerable pressure on firefighting resources because multiple incidents require attention at the same time.
“There is really no part of the UK that is immune to wildfire. Wherever there is vegetation that can burn, this could be grassland, heathland, woodland, moorland or vegetation alongside roads and railway lines, there is the potential for wildfire under the right conditions. It doesn’t require months of drought. Just a few weeks of hot, dry weather can dry grasses, leaf litter and other fine vegetation sufficiently for them to sustain a fire if an ignition occurs.
“Yes. Climate change is increasing wildfire risk by making periods of extreme heat and low humidity more frequent and more intense. This extends the amount of time each year when vegetation is dry enough to burn and increases the likelihood of extreme fire weather.
“Importantly, fire behaviour responds disproportionately to weather extremes. Once vegetation becomes critically dry, relatively small increases in temperature or reductions in humidity can produce much faster fire spread, taller flames and much more intense fire behaviour. A heatwave that is just one degree hotter, or a few percentage points drier, can therefore produce substantially more dangerous wildfires.
“The UK has made significant progress in preparing for wildfire. Many Fire and Rescue Services now have specialist wildfire capabilities, with personnel training in countries such as Spain, South Africa and the United States. National Parks and land managers have also developed wildfire management plans informed by experience from Mediterranean countries and other fire-prone regions.
“However, climate change is increasing wildfire risk faster than preparedness can fully keep pace. During extreme fire weather, the challenge is no longer simply how to extinguish one wildfire, but how to respond when many significant fires are burning simultaneously across the country.
“Looking ahead, improving resilience will require more than investment in firefighting. It will also require proactive landscape management to reduce fuel loads where appropriate, strengthen community preparedness and adapt to a future in which extreme wildfire conditions are likely to become more common.”
Our previous output on this subject can be seen here:https://www.sciencemediacentre.org/expert-reaction-to-uk-wildfires-2/
Declared interests
Joe McNorton: “No conflicting interests”
Thomas Smith: “No conflicts of interest to declare”
No others received.