The new year started with one of the most horrific wildfires in history: a blaze in the Los Angeles metropolitan area that killed at least five people and reduced thousands of homes to ashes. Two fires exceeding 10,000 acres – the Palisades Fire to the west and the Eaton Fire to the north – were intensified by extreme drought and Santa Ana winds reaching 100 mph.
Climatologist Daniel Swain told CNN that the Pacific Palisades Fire could become the costliest wildfire in history, saying he expects it to ravage the entire region. would exceed the economic losses caused by any other fire. According to NOAA, the costliest wildfire season to date (in 2024 dollars, accounting for inflation) was 2018, with $30 billion in losses, largely due to devastating fires in California. Among them, the Camp Fire in November was the most prominent, which devastated the city of Paradise, California, killing 85 people and destroying more than 18,800 buildings. That fire caused an estimated $12.5 billion in damage, making it the costliest fire in history.
Climate change's role in fires
The main way climate change worsens wildfires is through drying of vegetation. Prolonged high temperatures turn forests and grasslands into flammable materials, leading to faster, more intense fires. As with this week's fires, Southern California's early 2024 winter has been wetter than normal, boosting vegetation growth. However, the summer of 2024 was the hottest on record in California. The combination of record high temperatures and severe drought has led to the depletion of rich winter-growing vegetation. In addition, the rainy season in Southern California, which begins in October or November, has been delayed, and by January 2025, conditions are in place for a severe drought (Figure 1).
In an email, climate scientist Daniel Swain offered the following thoughts on the connection between climate change and California wildfires:
California’s fire season has been significantly lengthened due to climate warming. In addition, the overlap between the “extremely dry vegetation season” and the “offshore wind season” (October to January) increases. There is little evidence that climate change is affecting the Santa Ana winds themselves, but there is strong evidence that climate change is significantly increasing fire-prone weather conditions in Southern California in the fall and early winter (Goss et al. 2020, Climate change is increasing extreme weather conditions in California Potential for autumn 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 wet-to-dry “hydroclimate whiplash” shift (and thus vegetation growth). Abundant). ; See my new article Hydroclimate Fluctuations on a Warming Earth Additionally, California’s “shoulder season” (fall and spring) precipitation is expected to decrease with warming, exacerbating rising temperatures. The impact of interannual whipping has increased by 31-66% and 8-31%, respectively, since the mid-20th century.
There are two other important ways in which extended dry seasons due to climate change are worsening wildfires:
- More severe droughts lead to water shortages, making eradication and recovery efforts difficult.
- There are fewer safe days to conduct prescribed burning, making it difficult to reduce fuel loads in vulnerable areas before fire season begins.
According to a 2023 study, human-caused climate change increased the area burned in California by 172% between 1971 and 2021 and by 320% between 1996 and 2021. .
Comparison of Santa Ana strong winds in 2025 and 2011
This week's fires were sparked by strong Santa Ana winds, with gusts of at least 70 mph recorded at at least 32 sites in the Los Angeles area on Wednesday, January 8, with gusts reaching 100 mph at Mt. Lukens Truck Trail. hour, approximately 20 mph. The last time similar Santa Ana winds occurred was 13 years ago, from November 30 to December 1, 2011. Households were largely without power. Whitaker Peak (elevation 4,120 feet), about 50 miles northwest of Los Angeles, recorded wind gusts of 97 mph.
Fortunately, the Santa Ana winds of 2011 did not spark major wildfires. This was largely because Los Angeles was not suffering from a drought at the time. But for the 2025 event, the drought is very severe (Figure 1).
Dangerous fires to continue next week
There's no immediate end in sight for the extreme drought and strong Santa Ana winds that have battered the Southern California coast. Wednesday's strongest winds have subsided, but the overall pattern, of rising air pressure over the eastern Pacific and a flow of energy south across California pushing winds up slopes and out to sea, will continue into next week. Not only would this close the door to any significant precipitation, but it would also make it difficult to extinguish ongoing fires and tackle new ones.
Severe fire weather conditions are expected to continue along the Southern California coast through Friday, according to the National Weather Service Storm Prediction Center. Wind gusts could reach 20 to 30 mph in the valleys and 40 to 60 mph in higher elevations. After a brief lull, strong north-northeast winds are expected to pick up again this weekend, with the potential for more severe Santa Ana winds to develop on Monday and Tuesday. Meteorologists at the National Weather Service's Los Angeles field office already noted what's in store for next week during Thursday's forecast conversation:
“This will be concerning as no rain is expected and the period from Tuesday night into Wednesday will be the fourth event in this period. Given the above, the low rainfall in the area since spring 2024 and the With another offshore wind event on top of what we have seen so far, there are serious concerns that fire-sparking weather conditions may intensify. “Residents are urged to continue to monitor the latest information and take precautions to protect their lives and property. Be vigilant about measures. “
Intense fires are worsening air quality
According to the latest map from airnow.gov, large amounts of smoke from wildfires have covered much of the Los Angeles metropolitan area, putting air pollution conditions in the red “unhealthy” zone. 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 winds from the Northeast will push smoke from the Eaton Fire toward downtown Los Angeles on Monday and Tuesday, potentially interfering with the NFL playoff game scheduled for Monday night against the Los Angeles Rams. If you go out in smoke, be sure to wear a properly fitting N95 mask.
Spanish Translation: Carlos Roa, Senior Director of Press and Communications, VoLo Foundation
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