LA wildfires - links with climate change

Combined with rising temperatures, this is drying out vegetation, making the area more vulnerable to burning. Strong winds that have driven the fires are normal for this time of year, but recently are making fires more dangerous because conditions are often drier as a result of climate change.

• Human-caused climate change has made California hotter and drier, making it easier for fires to start and spread. This is causing a larger area to be burned every year. The area burned by wildfires in California annually is now five times bigger than in the 1970s - nearly all of this increase is due to climate change.
• Climate change is causing more intense fires in California. The number of days where large fires are possible has increased due to the burning of fossil fuels. Climate change is also making it easier for fires in California to spread quickly; about 25% more fires now spread extremely fast. 
• Climate change is making the fire season longer. There are twice as many days of fire weather today compared to the early 1970s and the number of autumn days with extreme fire weather has more than doubled in California since the early 1980s. Megafire “critical danger days” have tripled in southern California over the last 40 years. Climate-change induced heating and drying has caused 66-90% of the increase in California’s fire weather over the last few decades. 

The January 2025 fires are being driven by strong winds. While the winds are not unusual at this time of year, the delayed onset of the rains means that it is unusually dry. Climate change is thus increasing the probability of the strong winds and dry conditions overlapping, which together can intensify fires. 

• Climate change is making it less likely to rain in late fall and early winter when the hot, dry, Santa Ana winds peak. Much of Southern California had almost no rainfall since July 2024, despite being halfway into the normal rainy season - the second-driest period in 150 years.
• California had its hottest June and July and the second hottest October, with many of the hot days scientifically linked to climate change. 2024 was the hottest year on record globally, due to climate change. This heat and lack of rainfall left the vegetation tinder dry when the Santa Ana winds started.
• Climate change is making it harder to preventatively manage fires, because it creates more hot and dry periods, with up to 30 fewer days per year when it is safe to set pre-emptive controlled burns in parts of southern California. 

This science has been clear for many years. Oil, gas and coal companies knew the consequences of using their products since at least the 1970s. Rather than accept a switch to safer sources of energy, they funded public and lobbying campaigns to create unjustified doubt about climate science so they could keep making record profits.

Scientific studies have found that climate change worsened previous fires in California and the Western US:

• Western North America wildfire risk, 2015-16 - "Extreme vapor pressure deficits (VPD) have been associated with enhanced wildfire risk. Using one model, we found for 2015/16 that human influences quintupled the risk of extreme VPD for western North America."
• Western US fire weather risk, 1979-2020 - “We estimate that human-caused climate change contributed to an additional 4.2 million ha of forest fire area during 1984–2015, nearly doubling the forest fire area expected in its absence."
• Northern California wildfires, 2014 - "The fire season in northern California during 2014 was the second largest in terms of burned areas since 1996. An increase in fire risk in California is attributable to human-induced climate change."
• California wildfires, 1972-2018 - “During 1972–2018, California experienced a fivefold increase in annual burned area, mainly due to more than an eightfold increase in summer forest‐fire extent. Increased summer forest‐fire area very likely occurred due to increased atmospheric aridity caused by warming."