Latest news with #GuillermoRein
Yahoo
a day ago
- Climate
- Yahoo
What is a 'firewave'? Experts issue weather warning for UK cities this weekend
Experts have warned people in densely populated areas to be alert this weekend People in major UK cities including London have been urged to "stay alert" this weekend amid the threat of so-called "firewaves", as the fourth heatwave of the summer creates the perfect conditions for blazes to get out of control. Firewaves is a term used by researchers at Imperial College London (ICL) to describe a period of time when many wildfires break out in a city at the same time. Professor Guillermo Rein, lead researcher at ICL, said prolonged dry spells can lead to grass, plants and vegetation losing a lot of moisture, making even small sparks able to cause huge fires that spread quickly. Asked about the threat facing London this weekend amid the ongoing heatwave, Prof Rein told Yahoo News: "Stay alert, but keep calm and carry on. Be careful with anything that could start a fire in vegetation. Awareness and prevention are key." He warned that multiple, urban wildfires igniting at the same time could "overwhelm the fire services and force evacuations in just a few hours". The team at ICL pointed to 19 July 2022, which saw a series of unprecedented wildfires in London, which overwhelmed the London Fire Brigade (LFB) as it experienced its busiest day since the Second World War. The warning comes amid forecasts of extreme heat this weekend, with London especially at risk due to its vast green spaces next to residential areas. The LFB has dealt with three separate heath fires in the capital recently, while a wildfire warning was issued for most of Scotland for the 10th time this year following a large blaze on Arthur's Seat on Sunday. It told Yahoo News it considered the risk of wildfires in London at the moment as "severe". What is a 'firewave'? Firewaves refer to clusters of multiple wildfires erupting at once in urban environments, triggered by extended periods of hot, dry weather. They can start after several days without rain, when dry vegetation essentially becomes a highly flammable fuel. Human activities, such as accidental sparks or arson, often ignite them, but the underlying driver is atmospheric conditions that suck moisture from the land, known as vapour pressure deficit (VPD). When VPD is high, plants begin to struggle to get moisture to their leaves and begin to wilt, rapidly increasing how flammable they are. In ICL's research, they looked at how much water the LFB pumped during wildfire events in London and classed the most severe outliers as firewaves. They found that between 2009 and 2022, four firewaves occurred in London, one in 2018 and four in 2022. Over the summer of 2022, 40 hectares of grassland were destroyed, 37 buildings were damaged, five cars were destroyed and 88 homes were evacuated. Dr Douglas Kelley, land surface modeller at the UK Centre for Ecology & Hydrology, told Yahoo News: "Research by Imperial College London shows that just 10 days without rain can leave grass and plants, especially dead or brown vegetation left over from this year's droughts, ready to burn." What cities are at risk? Any big city with parks, green spaces and abundant vegetation could be hit, according to Prof Rein. Dr Kelley said that such places - people and nature meet - are known as the "urban–wildland interface". "We've seen these fires across England in recent years, and the blaze on Arthur's Seat in Edinburgh this week shows the risk is UK-wide," he said. "Cities around the world face similar dangers: this year's fires near Los Angeles and in Chile show how serious it can be." In the UK, London is particularly vulnerable to firewaves, given the large number of parks and green belts bordering densely populated areas, creating ideal pathways for fire to spread. Dr Kelley explained: 'When it's hot and dry, everyone needs to be extra careful outdoors. Most wildfires in the UK are started by people, often accidentally. 'Disposable barbecues in parks can ignite grass. Litter – especially glass bottles – can focus sunlight and spark fires. Cigarettes are a common cause. Staying alert and avoiding risky activities can make a big difference to you and other people nearby Other major cities like Manchester, Birmingham, and Edinburgh face similar threats, especially where urban expansion meets flammable vegetation. Health risks aside from the dangers of fire itself include smoke inhalation, while ecological damage can harm local plant and animal life. Prof Rein added: 'The potential for fires to spread into homes is very real.' Will firewaves and wildfires become more likely? Firewaves will become more likely in the UK as climate change intensifies heatwaves and dry spells, Dr Kelley warned. He said that UK Centre for Ecology and Hydrology research, alongside the Met Office, shows fires in 2022 'were made at least six times more likely by human-caused climate change'. He added: 'As temperatures rise, wildfires will pose a growing risk to people, property and nature, even in the UK. Scientists predict a surge in such events, with risks 'much greater now than a decade ago,' according to Professor Rein. Kelley said that countries like Australia, which have a long experience with wildfires, can help authorities in the UK prepare for similar outbreaks here. He said public campaigns can make people know when fire bans are in place, while the UK could learn more from other countries. "In Europe, the US, Canada and Australia, fire services also share resources across regions during major outbreaks," he said. "Similar planning and cooperation here, alongside preparation, prevention, public awareness and land management, will help reduce the risks."
Daily Mail
2 days ago
- Climate
- Daily Mail
Scientists warn a new weather phenomenon dubbed the 'FIREWAVE' will devastate UK cities as summers become hotter and drier
Scientists have warned that a new weather phenomenon dubbed the 'firewave' has the potential to devastate UK cities. As climate change makes summers hotter and drier, there is a growing risk that wildfires will spread within the heart of the UK's biggest cities. Coined by researchers at Imperial College London, the term firewave describes multiple wildfires simultaneously erupting in urban areas due to prolonged hot weather. This comes after firefighters in London rushed to battle three separate grass fires in 24 hours, as temperatures reached 33.3°C (91°F) in the capital. Using data from the London Fire Brigade, fire researcher Professor Guillermo Rein has identified the key factors which drive wildfire outbreaks in the city. Professor Rein found that just 10 days of extremely dry conditions are enough to significantly increase the chances of multiple fires igniting at once. Professor Rein told the BBC: 'Once the moisture content of the vegetation drops below a certain threshold, even a small spark can lead to a fast-spreading fire.' Now, as the UK swelters in the fourth heatwave this summer, Professor Rein warns that London could face another firewave this weekend. During prolonged periods of hot, dry weather, the vegetation in cities becomes desiccated enough to catch fire. However, Professor Rein's research found that it isn't heat or relative humidity which is the best predictor of firewaves. Instead, the key factor determining whether fires break out is a measure of how much water the atmosphere can extract from the land called the 'vapour pressure deficit'. The higher the vapour pressure deficit, the faster that vegetation dries out and the greater the risk of wildfires. Professor Rein says: 'Vegetation doesn't just become a bit more flammable, it becomes much more flammable.' The conditions which make firewaves possible are now becoming more likely, as human action continues to make the world a warmer place. 'Climate change is bringing more heatwaves and longer dry spells,' says Professor Rein. 'These conditions dry out fuels and increase the risk of wildfires. That risk is much greater now than it was even a decade ago.' Researchers found that the most important factor for predicting urban wildfires is a measure of how much water the atmosphere can absorb from the land called the vapour pressure deficit. These graphs show vapour pressure deficit against the number of wildfires (left) and the hours the London Fire Brigade spent pumping water for hoses (right) Professor Rein's research, published in the journal Fire Technology, found that there were four separate firewaves in 2022. That is compared to just one in 2018, and none in any other year from 2009 onwards. In 2022, that led to the L ondon Fire Brigade's busiest day since World War II as multiple fires erupted across the city on July 19. That included a blaze in Wennington, East London, which destroyed 37 buildings, five cars, and forced people to evacuate 88 homes. This year, an exceptionally warm, dry spring, followed by multiple heat waves, has greatly increased the risk of fires. The amount of UK land burnt by wildfires had already smashed the all-time record just four months into the year, with 113 square miles having been burned. This week, fire crews have been battling a large gorse fire raging across Arthur's Seat, Edinburgh, and the risk of further fires remains 'very high'. Professor Rein says he is concerned that wildfires, once largely limited to rural regions, could now pose a serious risk to urban populations. Scientists now warn that wildfires in urban areas across Europe are likely to become more frequent as climate change makes the conditions for fires to start more common. Pictured: A house burns in the Viseu district, Portugal, yesterday The researchers argue that the Met Office's definition of heatwaves doesn't reflect the extreme wildfire risk in some cases, and are calling for the Met Office to start using the term firewave He says: 'I worry about all other UK cities and other northern European cities in particular because climate change seems to be making green vegetation that was not flammable very flammable indeed. 'And these places don't have a history of dealing with wildfires, so don't have as much institutional experience as cities in the south of the continent.' London Fire Brigade Assistant Commissioner Tom Goodall told Daily Mail: 'The risk of wildfires in London is currently considered as severe. 'Below-average rainfall this year, coupled with high temperatures, also means the chance of fires spreading rapidly when they do occur.' However, Mr Goodall also stressed that 'the majority' of fires can be avoided if the public behaves 'responsibly'. The researchers are now calling for the Met Office to adopt the term 'firewave' to reflect the risk of wildfires in the urban environment. They argue that the current definition of a heatwave does not properly capture the extreme fire risk that occurs in certain weather conditions. A Met Office spokesperson told Daily Mail: The Met Office provides weather advice to emergency responders during wildfire incidents and advice on potential wildfire conditions to the UK's resilience community through the Natural Hazards Partnership Daily Hazards Assessment (DHA). But the Met Office has no mandate to provide a public wildfire warning service for the UK, and no such service exists in the UK.' HOW DO WILDFIRES AFFECT LOCAL TEMPERATURES? Wildfire smoke lingering in the air can block out the sun enough to cause measurable temperature differences at the surface, even after the flames have died down. Scientists say the interactions between smoke and the sun's rays can either cool the air or warm it; when the rays are scattered, the air becomes cooler, while temperatures rise when the rays are absorbed. A study published earlier this year found that the cooling effect can even extend to river and stream temperatures. Brown carbon, in particular, has been found to have a significant effect, as it is more likely than black carbon to reach higher levels of the atmosphere, according to NASA. But, the space agency explains, 'as particulate matter in the atmosphere, both can interfere with solar radiation by absorbing and scattering the sun's rays.' Brown carbon is a major product of wildfires, as it's created when grasses, wood, and other biological material burns. 'Most of the brown carbon released into the air stays in the lower atmosphere, but we found that a fraction of it does get up into the upper atmosphere, where it has a disproportionately large effect on the planetary radiation balance – much stronger than if it was at the surface,' Rodney Weber, a professor in Georgia Tech's School of Earth & Atmospheric Sciences, said last year in a study on the phenomenon. Fires can also cause temperatures to drop by transforming the landscape, and increasing a property known as albedo – or the measure of light reflected by a surface. As vegetation is destroyed in the fires, there is less foliage to absorb the sunlight and its warmth. Studies in recent years have found that the resulting cooling effect can linger for years, particularly during the winter months.
Daily Mirror
2 days ago
- Climate
- Daily Mirror
UK cities face devastating 'firewave' as scientists name areas most at risk
A rise in temperatures due to climate change has led to experts warning of a 'firewave' un urban areas. Hotter temperatures increase the likelihood of mulitple fires Brits in cities are facing a threat from a phenomenon known as ' firewaves ' as early as this weekend as climate change sends temperatures rising. Experts at Imperial College London, have been working with the London Fire Brigade to help predict when conditions are most likely to cause a so-called 'firewave', when long periods of hot weather trigger multiple urban wildfires that overwhelm emergency services. It comes following a large blaze on Arthur's Seat in Edinburgh and three separate heath fires in London amid a UK heatwave. Guillermo Rein, professor of fire science at Imperial College London, has said current forecasts could make London a fire risk by this weekend. His team's research says that dry weather 10 days in a row dramatically increases the likelihood of a number of fires igniting at the same time because of moisture being removed from vegetation. The Imperial College London team suggests the Met Office should adopt the term to reflect the risk of wildfires in urban areas during a heatwave. Rein has been working with the London Fire Brigade (LFB) to help predict firewave conditions. LFB Assistant Commissioner Tom Goodall added that he welcomed research that may help the prevention of fires. The LFB is "ready to tackle the threat of wildfires head-on to help protect London's communities and green spaces", Mr Goodall told the BBC. Professor Rein's research with the LFB looked at data going back to 2009. This helped identify what they think are the important factors that lead to wildfires in London. The factors include how much moisture can be extracted from the land, which is known as the "vapour pressure deficit". The more moisture extracted, the higher the deficit and an increased likelihood of fires starting. "Vegetation doesn't just become a bit more flammable," Professor Rein said. 'It becomes much more flammable." He continued: "Once the moisture content of the vegetation drops below a certain threshold, even a small spark can lead to a fast-spreading fire.' While most fires are started accidentally or deliberately by humans, a rise in temperatures is making the situation worse. "Climate change is bringing more heatwaves and longer dry spells," Professor Rein said. "These conditions dry out fuels and increase the risk of wildfires. That risk is much greater now than it was even a decade ago." He added: "I worry about all other UK cities and other northern European cities in particular because climate change seems to be making green vegetation that was not flammable very flammable indeed… And these places don't have a history of dealing with wildfires so don't have as much institutional experience as cities in the south of the continent." It is believed that urban environments like London could be the most at risk due to green spaces next to residential areas. In 2022, a summer in which London experienced temperatures of over 40C for the first time on record, the LFB experienced its busiest day since World War Two. Simultaneous fires broke out on July 19 that year. A fire in Wennington, East London, destroyed 37 buildings and five cars. A total of 88 homes had to be evacuated. "The potential for fires to spread into homes is very real," said Barking and Dagenham Borough Commander Blake Betts. "We're seeing more extreme weather events, and that's why the London Fire Brigade has adopted a much more proactive approach." The LFB has said it has invested in technologies such as drones to help with wildfire response, along with off-road vehicles to create firebreaks.
BBC News
3 days ago
- Climate
- BBC News
Hot, dry summers bring new 'firewave' risk to UK cities
Cities across the UK are facing a growing threat from an emerging phenomenon called "firewaves" as temperatures rise due to climate change, scientists have term, coined by researchers at Imperial College London, describes multiple urban wildfires triggered by extended periods of hot, dry warning comes as firefighters battled three separate heath fires in London and a dramatic gorse blaze on Arthur's Seat in Edinburgh in recent days, as this summer's latest heatwave left vegetation across both capitals dangerously fires, though now contained, highlight the increasing vulnerability of urban areas to wildfires - a risk that was once considered largely rural. Guillermo Rein, professor of fire science at Imperial College London, has been working alongside the London Fire Brigade to help predict when conditions are ripe for a "firewave".Based on current forecasts, he believes London could be at risk again by this Fire Brigade Assistant Commissioner Tom Goodall said he welcomes any research that helps predict the likelihood of wildfires service is "ready to tackle the threat of wildfires head-on to help protect London's communities and green spaces", he added. Prof Rein's research finds that, after ten consecutive days of very dry weather, vegetation becomes so desiccated across wide areas that the likelihood of multiple fires igniting simultaneously rises detailed incident data from the London Fire Brigade dating back to 2009, combined with weather records, the team identified key factors that drive wildfire outbreaks in of the most important is a measure of how much moisture the atmosphere can extract from the land, known as the "vapour pressure deficit".The higher the deficit, the drier the vegetation becomes, and the more easily it ignites."Vegetation doesn't just become a bit more flammable," explained Professor Rein, "it becomes much more flammable.""Once the moisture content of the vegetation drops below a certain threshold, even a small spark can lead to a fast-spreading fire," he added. Most fires are started by humans, whether accidentally or deliberately. But a warming world is creating conditions more conducive to these blazes."Climate change is bringing more heatwaves and longer dry spells," Prof Rein said."These conditions dry out fuels and increase the risk of wildfires. That risk is much greater now than it was even a decade ago."While the researchers focused on London, concerns are widespread."I worry about all other UK cities and other northern European cities in particular because climate change seems to be making green vegetation that was not flammable very flammable indeed," said Prof Rein."And these places don't have a history of dealing with wildfires so don't have as much institutional experience as cities in the south of the continent." Managing fire risk Urban environments like London, with their abundance of parks and green spaces bordering residential zones, are particularly concept of a "firewave" is meant to capture the unique danger posed when several fires erupt at once in densely populated areas, which has the potential to overwhelm emergency services and threaten homes and happened in the summer of 2022 when UK temperatures exceeded 40C for the first time on 19 July 2022, London Fire Brigade (LFB) experienced its busiest day since World War broke out simultaneously across the city, including a devastating blaze in Wennington, East London, which destroyed 37 buildings, five cars, and forced the evacuation of 88 Betts, a borough commander with the LFB, has extensive experience dealing with wildfires in urban emphasises the serious threat they pose, especially when open spaces are adjacent to residential properties."The potential for fires to spread into homes is very real," said Cdr Betts."We're seeing more extreme weather events, and that's why the London Fire Brigade has adopted a much more proactive approach." To meet this growing challenge, the LFB says it has invested in new technologies and now play a critical role in wildfire response, providing real-time aerial views that help commanders map fire spread and direct resources where they are needed most."The bird's-eye view from drones gives us a huge boost in situational awareness," explained a spokesperson from the LFB."It allows us to target our efforts where the risk to life and property is greatest."In addition to drones, the brigade has introduced off-road vehicles capable of reaching fires in difficult terrain, such as heathland and vehicles can be used to create firebreaks – using water to soak the ground to help stop fires from spreading Imperial College London researchers argue that the Met Office's current definition of a heatwave does not adequately reflect the wildfire risk in urban propose it adopts the term "firewave" to signal periods of extreme fire danger in cities - a concept they hope will inform future public safety strategies and climate resilience Met Office has been asked for comment. Sign up for our Future Earth newsletter to keep up with the latest climate and environment stories with the BBC's Justin Rowlatt. Outside the UK? Sign up to our international newsletter here.
Daily Mail
07-05-2025
- Science
- Daily Mail
Shocking report reveals the cities most vulnerable to climate disasters
A shocking report has revealed the 'sitting duck' cities which are most vulnerable to climate disasters. The report, produced by the Financial Times, warns that Amsterdam, Houston, and New York City are among those at risk of being flooded while Austin is at high risk of fires Meanwhile, several densely populated cities, including Lisbon, Naples, Athens, and Christchurch are at risk of both heat waves and flooding. Worryingly, experts say they don't know when these disasters could hit. Guillermo Rein, a fire sciences professor at Imperial College London, speaking to the Financial Times said: 'But at the global level, they are becoming more probable. 'In the next year there's going to be a big wildfire destroying a big community. 'But we have absolutely no idea where that is going to happen.' Described by climate scientists as 'sitting ducks', scientists say that some cities have been 'lucky' to not experience an extreme climate event so far. In these most at risk areas the natural geography, climate conditions, and city planning have combined to create an exceptional risk. Yet many of these cities have already come close to complete destruction. In August last year, Athens, which is home to 3.6 million people, narrowly escaped catastrophe as a wildfire reached the outskirts of the city. The fire scorched 40 square miles of land northeast of the city, killing one woman and forcing thousands to flee their homes. However, the flames stopped just short of entering the city centre where even more serious damage could have taken place. Dr Thomas Smith, an expert on environmental geography from the London School Of Economics And Political Science, told the Financial Times: 'What was missing was the wind element.' Had there been strong winds, like the Santa Ana winds which drove the Los Angeles wildfires, the situation might have been far more severe. For sitting duck cities like Athens, a major risk factor stemsfrom their proximity to the wilderness. As cities spread, they push further into the surrounding grasslands, forests, and fields where wildfires are more prone to start. Scientists call this area the wildland-urban interface and estimate that it makes up about 4.7 per cent of the planet's surface. In Europe, the wildland-urban interface covers 15 per cent of the continent and is home to more than 60 per cent of the population. While climate change does not directly cause wildfires, it makes the conditions for intense blazes significantly more likely. The risks of fire are increased by warming temperatures which create dry vegetation, and combined with strong winds the outcomes can be deadly. The World Weather Attribution - a network of researchers from the U.S., UK and a number of other European countries - warned that the hot, dry, and windy conditions that drove the Los Angeles wildfires are about 35 per cent more likely due to global warming. In the UK, unusually warm spring weather means the country has already passed the record for land destroyed by wildfires. Since the start of 2025, more than 113 square miles of land has been consumed by fires across the country. However, it is not only wildfires which pose a threat to sitting duck cities around the world. According to an analysis by Moody's, a financial research firm, roughly 2.4billion people now live in areas that are at risk of inland river or flash flooding. In the U.S., Dallas, Houston, Washington DC, New York, and Sacramento are all at extreme risk of flooding due to climate change. Dallas is especially threatened by flooding due to the city's rapid growth. As it has grown city planners have added concrete or asphalt areas which cannot absorb water meaning that when heavy rain comes, it runs off these impermeable surfaces and rapidly collects, triggering flash flooding. In 2022, a sudden deluge of 38cm of rain in 24 hours triggered a flood which submerged homes and swept away cars. Other cities considered sitting ducks for flooding include Amsterdam, Ahmedabad, and Buenos Aires. Just like the risk posed by wildfires, the changing climate has made flooding not only more frequent but also more severe. Following devastating flooding in Valencia, Spain last year scientists said that the catastrophic event was fuelled by climate change. Dr Friederike Otto, head of the World Weather Attribution at the Centre for Environmental Policy, Imperial College London, said: 'No doubt about it, these explosive downpours were intensified by climate change.' An increasingly warm climate has even made some cities vulnerable to wildfires and flooding. Wildfires destroy vegetation such as trees which makes the soil less able to absorb water. This means areas which have suffered wildfires are more likely to be affected by flash flooding if heavy rain follows. According to research, the elevated risk of flooding can persist for up to a decade after a fire. Cities considered sitting ducks for both fire and flooding are Lisbon, Athens, Naples, Cape Town, Sydney, and Christchurch. Recent studies have found that a number of major cities, including Dallas, are now undergoing a process which is being called 'climate whiplash'. This means they are facing both increasingly severe periods of dry weather and more extreme wet periods. These cycles of drought and flooding make cities more vulnerable to climate disasters and give authorities less time to prepare for extreme conditions.
