The new year begins with one of the most horrific wildfire events in world history: an urban blaze in the Los Angeles metropolitan area that has killed at least five people and reduced thousands of homes to smoldering rubble. Two major fires exceeding 10,000 acres – the Palisades Fire in Los Angeles' western suburbs and the Eaton Fire in the northern suburbs – were fueled by severe drought and wind gusts of 100 mph (161 kph). event.
Climate scientist Daniel Swain said on CNN that the Pacific Palisades fire alone could become the costliest wildfire in history, and he predicted that, overall, the fire Fires will ravage the area will It became the costliest wildfire incident in history. According to NOAA, the most expensive wildfire season on record (in 2024 dollars, accounting for inflation) was the 2018 forest fire season, with $30 billion in losses, largely due to severe fires in California. These include the most destructive wildfire on record, the Camp Fire in November, which devastated the city of Paradise, California, killing 85 people and destroying more than 18,800 structures. That fire cost approximately $12.5 billion, making it the most expensive single fire in world history.
Climate change's role in fires
The main way climate change is exacerbating wildfires is through drying of vegetation. Prolonged heat turns forests and grasslands into tinder, fueling faster, more intense burns. As with this week's fires, a wetter-than-usual Southern California winter in early 2024 has enhanced vegetation growth. But in the summer of 2024, California experienced its hottest summer on record. Record high temperatures combined with a near-record drought have dried out much of the vegetation that grew during the wet winter. In addition, Southern California's rainy season, which usually begins in October or November, was delayed, and by January 2025, a severe drought occurred (Figure 1).
In an email, climate scientist Daniel Swain provided the following insight into the climate change/wildfire connection in California:
As the climate warms, California's fire season has lengthened significantly. Crucially, this increases the overlap between the extreme dry vegetation season and the offshore wind season (October to January). There is little evidence that climate change is affecting the Santa Ana winds themselves, but there is strong evidence that climate change is greatly increasing the incidence of extreme fire weather conditions in Southern California in the fall and early winter (Goss et al. 2020, Climate change is increasing) California Potential for extreme fall wildfires). Climate change is also increasing the seasonal overlap of dry/windy conditions (Swain 2019), and there is evidence that further warming will increase the “hydroclimate whiplash” transition from wet to dry (which results in abundant vegetation growth followed by subsequent drying ; see my new paper, Hydroclimate Fluctuations on a Warming Earth). Additionally, California's “shoulder season” precipitation (fall and spring) may decrease with warming, increasing the effects of warmer temperatures and increased evaporative demand (drying vegetation) throughout the year.
There are two other important ways that extended dry seasons due to climate change are worsening wildfires:
- A more severe drought has left water supplies scarce, hampering firefighting efforts and recovery.
- There are fewer safe days for prescribed burning, making it more difficult to reduce fuel loads in vulnerable areas before fire season begins.
A 2023 study found that human-caused climate change increased the area burned in California by 172% from 1971 to 2021 and by 320% from 1996 to 2021. Further increases in forests are expected to range between 3% and 52%.
Comparing 2025 and 2011 Santa Ana High Wind Events
This week's fires were sparked by strong winds from a Santa Ana wind event. On Wednesday, January 8, at least 32 weather stations in the Los Angeles area recorded wind gusts of at least 70 mph, with the highest gust reaching 100 mph on the Mt. Lukens Truck Trail. (161 km/h). The last Santa Ana wind event of similar intensity occurred 13 years ago, from Nov. 30-Dec. January 1, 2011. of Altadena and Pasadena. Whitaker Peak (elevation 4,120 feet), about 50 miles (80 kilometers) northwest of Los Angeles, recorded wind gusts of 97 mph (156 km/h).
Fortunately, the 2011 Santa Ana storm did not cause major wildfires. This was largely because Los Angeles was not experiencing a drought at the time. But in the 2025 event, a severe drought occurred (Figure 1).
CALIFORNIA: Here's a great look at the wind conditions pilots and firefighters face while responding to California fires. #cafire #palisadesfire #eatonfire
It's difficult to get the flame retardant to where you want it because of the wind on top of the ridge blowing the product and… pic.twitter.com/ijzJvPZp9W
— Hotshot Wake (@HotshotWake) January 9, 2025
Dangerous fire weather to continue into next week
There's no immediate end in sight for the bone-dry conditions and strong Santa Ana winds plaguing the Southern California coast. The strongest winds since Wednesday have weakened, but the overall pattern — strong upper-level high pressure over the eastern Pacific, with energy moving south through California and pushing winds downslope and offshore — will continue into next week. Not only will this close the door to any significant precipitation, but it will make it more difficult to extinguish existing fires and address any new fires.
Severe fire weather conditions are expected to continue along the Southern California coast through early Friday, according to the National Weather Service Storm Prediction Center. Winds could reach 20-30 mph in the valleys and 40-60 mph in higher elevations, especially Thursday night. After a brief break, another strong north to northeasterly wind is expected this weekend, with the potential for more severe Santa Ana winds Monday and Tuesday. Forecasters at the National Weather Service's Los Angeles field office already noted what's in store for next week during Thursday's forecast discussion:
“This may result in no rain being forecast and the period between Tuesday night and Wednesday will be the fourth maritime event in this period. Given previous conditions, there are serious concerns that fire weather conditions may intensify, with the region having been affected since spring 2024.” There has been little rainfall and on top of all we have seen so far, there is another offshore wind event. Residents are asked to pay close attention to the latest information and remain vigilant to protect their lives and property.
Severe fires are worsening air quality
According to the latest map from airnow.gov, large amounts of smoke from wildfires have covered much of Los Angeles, and air pollution conditions are in the red “unhealthy” range. Air quality should improve over the weekend as winds ease and firefighters make progress in containing the fire. However, a new wave of Santa Ana nor'easters on Monday and Tuesday will push smoke from the Eaton Fire over downtown Los Angeles, potentially interfering with the Los Angeles Rams' NFL playoff game scheduled for Monday night. If you go out into a smoky environment, be sure to wear a suitable N95 mask.
Read more: How to protect yourself from wildfire smoke
Only 28% of U.S. residents regularly hear about climate change in the media, but 77% want to know more. By 2025, you can show Americans more climate news.
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