Climate change made devastating LA fires more likely, scientists say
Analysis found the hot, dry and windy conditions that drove the fires were 35% more likely due to 1.3C of warming.
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Your support makes all the difference.Human-driven climate change made the devastating Los Angeles wildfires more likely, an international team of scientists has found.
Wildfires in the Californian city started on January 7 and spread quickly, killing at least 28 people and destroying more than 10,000 homes, racking up billions in costs and leaving thousands of people homeless.
The World Weather Attribution network of researchers from the US, UK and a number of other European countries warned the hot, dry and windy conditions that drove the fires were about 35% more likely due to global warming – driven primarily by burning fossil fuels.
It added that the fire-risk conditions could become another 35% more likely if global temperatures rise 2.6C above pre-industrial levels, for which the world is currently on track by 2100.
The LA fires were fanned by strong “Santa Ana” winds and fed by drought conditions since May 2024 which left grasses and brush dry and highly flammable, while wet winters in the previous two years had created more vegetation growth that added more fuel to the fire.
The researchers examined the “fire weather index” which uses the temperature, humidity, rainfall and wind speed in the preceding weeks and days to characterise the conditions that make fires more likely.
They said while coastal southern California is an environment “highly prone to catastrophic wildfires”, the extreme fire weather index condition that drove the LA fires is getting more likely due to climate change.
The hot dry conditions behind the wildfires are expected to occur every 17 years in today’s climate, which has warmed 1.3C since pre-industrial times, making them 35% more likely to occur than in a world without global warming, and they are about 6% more intense, the researchers said.
The low rainfall between October and December, a period when rain usually brings an end to the region’s wildfire season, is now about 2.4 times more likely than in pre-industrial times, an analysis of historical weather data found.
Hot, dry conditions are being seen for an extra 23 days each year on average, increasingly overlapping with the Santa Ana winds that spread the wildfires, they said.
The researchers combined weather data with climate models for their analysis, but while the models indicated a climate change influence on hot, dry, windy conditions, they did not show a significant impact on rainfall or the ending of the fire season.
But the scientists said they were confident climate was driving the changes, based on existing studies and real-world weather data analysis, which show an increased likelihood of LA fires.
Dr Clair Barnes, World Weather Attribution researcher at the Centre for Environmental Policy, Imperial College London, said: “Climate change increased the risk of the devastating LA wildfires.
“Drought conditions are more frequently pushing into winter, increasing the chance a fire will break out during strong Santa Ana winds that can turn small ignitions into deadly infernos.
“Without a faster transition away from planet-heating fossil fuels, California will continue to get hotter, drier, and more flammable.”
The analysis also warned the elderly, people with disabilities, those on lower incomes without their own cars, and people who received late warnings were disproportionately affected by the wildfires.
It said the fires exposed critical weaknesses in the city’s water infrastructure, and highlighted the need for investment in better water systems and stronger measures to adapt to climate change and prepare for more frequent fires in the future.
Roop Singh, head of urban and attribution at the Red Cross Red Crescent Climate Centre, said: “Climate change set the stage, helping turn the hills around LA tinder-dry.
“However, hurricane-force Santa Ana winds, the rapid spread of fires into urban zones, and a strained water system all made the blazes extremely difficult to contain.
“These fires have highlighted just how vulnerable California is to winter wildfires, underscoring the need for better preparation for a more dangerous future.”
Dr Friederike Otto, co-lead of World Weather Attribution and senior lecturer in climate science at Imperial College London, warned America is experiencing the “devastating consequences of fossil fuel warming”, from wildfires in the west to violent hurricanes in the east.
“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,” she said.