How and Why the LA Wildfires Grew So Fast—and Lessons for the Future
CAS Earth and environment professor explains how high winds and drought, combined with climate change, created a perfect storm
A search and rescue crew member sifts through the rubble of a recent fire. Photo by Richard Vogel/AP Photo
How and Why the LA Wildfires Grew So Fast—and Lessons for the Future
CAS Earth and environment professor explains how high winds and drought, combined with climate change, created a perfect storm
As Los Angeles starts to recover from the catastrophic losses from their deadly wildfires—which so far have killed 25 people, displaced 100,000, and caused tens of billions of dollars in damages—many wonder what first sparked the fires.
While officials investigate possible causes, including arson, sparking power lines, and errant fireworks, an expert told NBC News that natural causes are more plausible than arson, due to heavy wind conditions. No matter the cause, scientists say that the weather and climate conditions when the fires started January 7 created a recipe for disaster for the swift spread of the flames. Continued strong winds have kept the country’s second-largest city by population at risk for further calamity.
BU Today spoke with David Demeritt, a College of Arts & Sciences professor of Earth and environment. Demeritt is a geographer whose research focuses on environmental policy, especially the management of flooding, wildfire, and other environmental risks. Before joining BU in 2023, he taught at King’s College London for over 20 years and is a member of the Peer Review Colleges for both the Natural Environment Research Council and the Economic and Social Research Council. Demeritt is also an elected fellow of the Academy of Social Sciences.
Q&A
with David Demeritt
BU Today: Why have these Los Angeles fires spread so fast and ferociously?
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BU Today: How do the dry conditions make the problem worse?
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BU Today: How are these fires different from previous fires?
It’s important to recognize several things about the current fires in LA that make them different from past fire disasters in California. First, this is happening in the winter (because of Santa Ana winds), rather than in the more typical fire season in the West, which is during the late summer, when high temperatures and dry conditions raise the risk of ignition from dry lightning and increase the probability that any ignition will catch hold and be difficult to put out.
Second, while some of the fires in Los Angeles County, like the Kenneth fire in the wildland, have their primary fuel source coming from the vegetation that sends out embers affecting isolated homes—something on which my BU colleague Ian Sue Wing [a CAS professor of Earth and environment] has done some cool econometric modeling—the Palisades fire, in particular, has become an urban conflagration in which much of the fuel is provided by buildings. So it is not clear that trimming the vegetation to manage fuel loads on the landscape is going to mitigate the risk all that much.
BU Today: To what degree is climate change responsible for these fires?
It doesn’t help, but attribution is tricky. All of the [preceding] climate events—heavy rainfall stimulating vegetation growth, drought, Santa Ana winds—occur “naturally.” And, as I said before, a history of fire suppression and the ignition risk posed by aboveground electrical wires also play an important role both in triggering this event and magnifying its severity.
Focusing on climate change leads to a certain kind of paralysis insofar as it suggests that unless we get the entire planet on board to reduce emissions to minimize climate change, there is nothing we can do. There are lots of things that we can do to make disasters like this less likely and less severe, like managing fuel loads to lower the risk, preventing housing development in places that are prone to wildfire, improving building standards and materials to reduce structural ignitability, and getting homeowners and communities to do more to create defensible space around homes and housing developments. Also, addressing evacuation routes and improving preparedness, so that when fires do occur, people can get out safely and in a way that doesn’t impede fire suppression efforts by clogging the roads and putting people at risk of burning in their gridlocked cars.
BU Today: What lessons are we likely to take away from these fires?
It’s early days yet, and I’m not optimistic about the prospects for much rational deliberation in a society so badly polarised and in awe of social media algorithms that promote bat-[expletive] crazy conspiracy theories and outrage—particularly, but not exclusively, on the right.
The financial hit for the insurance industry is going to be huge. Nationwide the insurance industry has been struggling with losses from climate-related extreme events. Many were withdrawing from California. This will only accelerate that trend. The state runs an insurance scheme of last resort, but it’s expensive and will likely become even more so. That will have implications for housing markets both regionally and nationally.
By contrast, I expect the policy response will be slower and much less effective. I’d imagine that some of the emergency evacuation planning for Los Angeles will get updated, after a good bit of blame-gaming. Some of the evacuations were handled badly. There may also be some renewed emphasis on fuel load management. But California is already relatively proactive in that area (at least compared to other parts of the country), and the circumstances in Los Angeles and Ventura Counties—with lots of shrubland and mountains surrounding the second-biggest [network of urban communities] in the US—are relatively distinctive. It’s not clear that what you’d need to do in LA is all that transferable to other parts of the West.
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