The devastation from the Palisades Fire is shown in an aerial view in the Pacific Palisades neighborhood of Los Angeles, Monday, Jan. 27, 2025. (AP Photo/Jae C. Hong)
YSE experts discuss the environmental and public health impacts of the fires as well as how fire-prone regions can prevent and manage the spread of wildfires in the future.
The Palisades, Eaton and Hughes fires that broke out in Los Angeles County in January consumed more than 45,000 acres and destroyed more than 15,000 structures — many of them businesses and homes. The fires, fueled by a hotter, drier climate and Santa Ana winds reaching 100 mph, killed 28 people. Additional fires have broken out in recent days prompting more red flag warnings and evacuations in Southern California. YSE News spoke with faculty experts Jennifer Marlon, senior research scientist; Shimon Anisfeld, senior lecturer and research scientist in water resources and environmental chemistry; and Paul Anastas, the Teresa and H. John Heinz III Professor in the Practice of Chemistry for the Environment, about what can be done to decrease the risks and prepare for future wildfires in the face of climate change.
Q. What are the primary factors driving the fires, and what conditions are making them so difficult to fight?
Marlon: The Santa Ana winds peak in December and January. So, in a world where we didn't typically get big wildfires in the winter, normally they wouldn't necessarily coincide, but climate change shifts our seasons. It's making wildfire season longer and heat wave season longer. When the temperatures are higher and the drought is more extreme, and there’s less humidity in the air and moisture in the soils, suddenly we are seeing unusual fire behavior, unusual winds. The whole nature of how fire operates on landscapes is now different. When a fire is moving at five football fields per minute, there's no way of getting out of harm's way.
One of the interesting things about wildfire is that what your neighbor does has a really big effect on your risk. Fire connects us and ties us together.”
Jennifer Marlon Senior Research Scientist
Anisfeld: Climate change is increasing the variability in the hydrologic cycle, so driving both more floods and more droughts. In the case of southern California, we had a couple of very wet winters that led to lots of vegetation growth — and then we had a very dry start to this winter — so all that dried-out vegetation became fuel for these intense fires. This is all happening at the wildland-urban interface where we are developing out into chaparral ecosystems, which are naturally fire prone. Once you have these massive fires that are burning both ecosystems and structures, you are not going to have enough water flow from hydrants to put the fire out effectively, especially in hilly areas like Pacific Palisades where you need to pump the water up to higher-elevation tanks to create the necessary water pressure.
Q. What are some of the immediate and longer-term impacts of the fires on the environment and public health?
Anastas: One piece of the tragedy of the wildfires is that seemingly harmless everyday materials can be transformed by the fire into extremely toxic chemicals. It is known that under the right conditions, fire can incinerate PVC pipes and siding into toxic dioxin and other chlorinated organics. This is true of a myriad of products that we use every day, including electronics and cleaners. During and after fires, the debris should be assumed to be hazardous. It’s not just harmless ash.
Anisfeld: When a house burns, toxic chemicals are released and generated and some of them can end up in drinking water by infiltrating groundwater or running off to surface water sources. Also, once parts of the water system lose pressure because of broken pipes, contaminants can be directly drawn into the pipes. Another concern is the firefighting foam that often contains heavy metals and other toxics and can end up contaminating water supplies. Lastly, when it rains on fire-scarred hillslopes, you can get a lot of sediment/ash running into reservoirs, which can create long-term problems.
Q. How can fire-prone regions prevent and manage the spread of wildfires?
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Marlon: We know that human-caused climate change is making these events more likely, more severe, and more costly. This is not the end, and in many cases, we're going to see more of this to come. We could certainly develop our cities and towns in different ways. There are many things that communities can do to enforce stricter building codes on what building materials are being used, and building density, such as closeness of homes. Oftentimes, when the decision is on the table, people don't want to pay a little bit more to build a house with more fire-resistant materials or assemble the roofs in ways that don't allow embers to get inside. That's going to add thousands of dollars to a home or a building, and that seems like a lot of money in the moment, and it is. However, we're paying a lot more down the road. It's a challenging trade-off. Even if your house didn't burn down, your rates are being affected. Insurance companies are always looking to hedge and pool the risk, but at some point, there isn't going to be any place left where it's a good investment for them.
Q. What can individuals do to lessen the impact of fires on their homes and property?
Anastas: Plastics, materials with halogens — chlorine, bromine, fluorine — are often the worst actors during and after fires. They can be found in household products and materials such as pipes, textiles, and electronics. One useful step would be to eliminate these types of products to detoxify your home in case of fire.
Marlon: One of the interesting things about wildfire is that what your neighbor does has a really big effect on your risk. Fire connects us and ties us together. You can clear the vegetation around your house that acts as fuel for fires, but there also may be lots of vegetation around your neighbors’ homes. Residents also can be mindful of tolerating prescribed burns, which is much better for fighting fires in the long run. We have lots of tools in our toolbox. It’s about coordinating efforts more closely to make better decisions and helping people understand the tradeoffs and the nature of their risks.