Latest news with #firewaves
Yahoo
2 days 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."
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. 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