An Imperial wildfires expert is also warning that following the fires, toxic fumes are now a concern in Los Angeles.
The fires broke out around LA on 7 January and wreaked havoc for nearly three weeks. But rainfall over the weekend has helped firefighters contain the flames.
A study from World Weather Attribution showed that human-caused climate change made the ferocious wildfires in Los Angeles more likely.
Now, Imperial's leading fire science expert, Professor Guillermo Rein from the Department of Mechanical Engineering, says concerns are turning to the hidden danger created by smouldering synthetic materials, batteries, chemicals and other household items that can produce as many fumes as raging flames.
Once the flames of the wildfires have been put out, smouldering fires continue to burn, releasing airborne chemicals that pollute the air being breathed by emergency workers and people returning to their homes, and spreading across a wide area.
Professor Rein says: "Smouldering is the hidden danger of urban fires – producing as many fumes as raging flames.
"And because what's burning in the LA fires isn't organic material like trees and vegetation, but synthetic materials like cleaning products, acrylics in carpets, batteries and plastics - the plumes of smoke produced from smouldering are going to be highly toxic."
Research studies are starting to show the long-term health impacts from smouldering fumes.
Professor Rein continues: "Smouldering in LA has been continuing for weeks - it's important to do everything we can to protect emergency services, people returning to their homes, and people in surrounding neighbourhoods from these hazardous fumes – by using masks, putting on air conditioning, and avoiding the outdoors."
A chance to build back better
The times following destructive fires are the best opportunity to improve building regulations and safety practices, Professor Rein explained, such as the period after the Great Fire of London in 1666 which resulted in incentives to rebuild the city from brick rather than wooden structures.
"This is the chance for LA to build back better – our studies of Californian urban fires have shown that with fire-resistant materials in the decks and walls, mesh in attic vents to stop fire spreading, and double-glazed windows we can greatly reduce the probability of damage to a house during a wildfire."
Fossil fuel burning contributed
The World Weather Attribution study also warns that Los Angeles will face even greater fire risk if humans continue to rely on fossil fuels, rather than transitioning to renewable energy, which is the most effective way to cut planet-heating emissions.
Dr Friederike Otto, co-lead of World Weather Attribution and Senior Lecturer in Climate Science at Imperial College London, said:
"Climate change is continuing to destroy lives and livelihoods in the US.
"From violent hurricanes in the east, to nightmarish wildfires in the west, Americans are experiencing the devastating consequences of fossil fuel warming.
"In 2025, the choices facing world leaders remain the same – to drill and continue to burn oil, gas and coal and experience ever more dangerous weather, or transition to renewable energy for a safer and fairer world."
[Top image credit: California National Guard under Creative Commons]
