Health, housing and the path ahead: UC Berkeley researchers on the Los Angeles fires

What health effects do urban fires like these pose that wildland fires do not? With the destruction of so many structures in Los Angeles, particularly homes, what concerns you about the immediate and longer-term health risks?

Fine particulate matter (PM2.5) air pollution from wildfires has been shown to be more harmful to human health than PM2.5 from other sources. Emerging evidence is showing that smoke from burning structures — compared to biomass, such as trees and other vegetation — contains an even higher concentration of certain harmful metals, including known carcinogens.

In the short term, exposure to wildfire smoke increases the risk of emergency department visits and hospitalizations for various health issues, particularly for already vulnerable populations. Unhoused individuals and those lacking access to resources like central air conditioning or air filtration are particularly at risk. Public health departments must prioritize clear communication about these risks, ensuring that vulnerable populations receive accessible and understandable information and have access to a safe place to seek shelter and clean air.

Wildfires also have lasting health impacts. Smoke exposure contributes to long-term health effects, alongside the mental and physical toll of evacuations and the loss of homes. Moreover, wildfires can contaminate groundwater and leave smoke residue and soot, potentially affecting ecosystems and communities for years. Addressing these challenges requires both urgent short-term interventions to protect those affected and ongoing monitoring of water, soil and air quality to mitigate long-term harm.

— Lara Schwarz, postdoctoral scholar in the Environmental Quality and Underlying Inequities in Society Lab at the UC Berkeley School of Public Health

You study the intersection of housing and climate. How did housing policy exacerbate the climate crisis that led to this catastrophe, and how will this climate-change-linked disaster impact housing in Los Angeles?

Housing policies in L.A. — as in much of the U.S. — have both exacerbated climate change itself and increased human vulnerability to its impacts. Exclusionary and car-oriented housing policy has blocked the growth of compact, walkable neighborhoods while subsidizing housing in sprawling, car-dependent neighborhoods. These policies force people to drive long distances to accomplish daily activities, and to consume vast amounts of energy, materials and land for their housing. This has resulted in much higher per capita carbon pollution in the U.S. than in peer countries with similar standards of living.

By limiting the supply of housing in less vulnerable urban locations, these same policies disperse housing development out into the wildland-urban interface (WUI). The low housing densities characterizing WUI development mix flammable vegetation with ubiquitous ignition sources from human habitation. These developments often feature disconnected road networks that hamper firefighting and evacuation.

What’s more, these policies have resulted in a national housing shortage, one that’s especially acute in coastal California. Finding temporary housing for people forced from their homes will be challenging.

Fortunately, recent local and state housing reforms have begun to encourage new housing in existing communities that is less polluting and more climate-resilient.

— Zack Subin, associate research director at the UC Berkeley Terner Center for Housing Innovation

What aspects of the urban landscape made these areas of L.A. prone to severe fire? Is there evidence that ‘home hardening’ techniques may have helped reduce the danger?

The areas burning in L.A., such as the Santa Monica Mountains, have a long and extensive fire history. Malibu, for instance, has had over 30 wildfires in the last 100 years. Dense vegetation that regrows quickly fuels fires that can spread into neighboring population centers. When Santa Ana wind events occur, winds are channeled through some of these areas and can push fires rapidly into communities.

While we don’t have on-the-ground data from these fires yet, we do have growing evidence that creating defensible space, like limiting vegetation around homes, and home hardening, such as sealing vents and installing fire resistant roofs and siding, can have real impacts on reducing destruction. Some of this evidence comes from on-the-ground damage inspections from CAL FIRE and NIST, while other evidence is generated during large-scale testing of full structures burning in a wind tunnel at IBHS. The Berkeley Fire Lab has worked with both partners to learn from this data and incorporate it into new regulations and guidance.

— Michael Gollner, associate professor of mechanical engineering

What should policyholders and policymakers watch for and expect in the weeks and months ahead in California? Is our current approach to insurance sustainable?

In the short and medium term, giving insurers more rate and reducing their costs should get insurers in California to start writing and renewing insurance again, as they said they would. But in the longer run, insurers are not going to be able to rate increase their way out of the climate crisis.

Climate scientists tell us that the failure globally and in the United States to transition from fossil fuels and other greenhouse gas-emitting industries means that global temperatures will continue to climb. As a result, there will be more extreme and severe weather-related catastrophes, which will kill and injure more people and destroy more homes, businesses and whole communities in this country and globally. This also means that insurers’ losses will keep climbing. The growing risks and losses from climate change-driven events will outrun rate increases and other regulatory changes granted to insurers in the longer run.

The failure to transition from fossil fuels and other greenhouse gas-emitting industries in this country and globally means that we are marching toward an uninsurable future in this country and across the globe. Florida, Louisiana and California are not alone. The New York Times found at least 18 states where insurers are raising rates and reducing the writing or renewing of insurance due to climate-driven extreme weather-related events.

Insurance availability and pricing is the canary in the coal mine for the climate crisis, and the canary is about to expire.

—Dave Jones, director of the Climate Risk Initiative at the Center for Law Energy & the Environment; former California Insurance Commissioner

What does climate fiction, and the humanities in general, offer to help us understand disasters like these fires that more science-based disciplines do not? How can climate fiction novels help us imagine different futures?

I first taught a seminar on climate fiction in 2019. I had taught science fiction and post-apocalyptic fiction before, but it was the first time I’d created a class about the human experience in relation to environmental change. I stopped teaching it in 2021, in part because climate change has become so pervasive, so insistent, so “realistic,” that it shadows contemporary fiction more broadly. Climate fiction is no longer predictive — it is descriptive, a distinction famously made by speculative fiction icon Ursula K. Le Guin.

Though I could be wrong, it seems to me that there are relatively few examples of science fiction and post-apocalyptic fiction that feature wildfire as a primary thematic effect of climate change. More often, heat and drought (as well as sea-level rise) are central plot drivers in climate fiction, perhaps because these are more systemic eco-disasters (what critic Rob Nixon calls “slow violence”) as compared to the seemingly abrupt cataclysms of wildfire (or flood). Of course, what is happening now with wildfire in the U.S., especially California, as well as in places like Canada and Australia, is hardly sudden — the conditions that have created this intensifying scourge have a clear political and environmental history.

There is a remarkably robust subgenre of apocalyptic movies that portray the spectacular destruction of Los Angeles, by earthquake, pandemic, meteor strike, alien or monster attack, among other cataclysmic misfortunes. We love to see L.A. destroyed in fiction, which explains why the current wildfire disaster may seem “like a movie.” But it is devastatingly real, no longer a speculative fantasy.

I expect that it will soon inspire a new wave of climate fiction. Hopefully some of these future imaginative writings will not only reflect the blindness and failure of political will that have gone into the making of this eco-crisis, and the suffering it is leaving in its wake, but they will also give us a way forward toward imagining a less destructive future.

— Katherine Snyder, associate professor of English

A great deal of news coverage of the fires has focused on devastation seen in wealthy areas, like the Malibu coastline and among celebrity homes. Why might the perception that these fires are primarily affecting the wealthy be a misconception or oversimplification?

Generally, natural disasters are more multifaceted than the dominant narratives that often develop around them can convey. For instance, following Hurricane Helene, conceptions of rural Appalachia as a white community made invisible the experiences of Black households. This has the effect, post-disaster, of not bringing full attention to the diversity of needs present in all communities.

In Los Angeles, major media focus on the Pacific Palisades fire has created a narrative that only wealthy households have been impacted. However, this is inaccurate. There have been six fires throughout the region that have affected various neighborhoods and households. In the Eaton Fire, a historically Black, middle-income community in Altadena has burned. As Andrew Rumbach of the Urban Institute has noted, even within Pacific Palisades, mobile home parks were impacted.

In any disaster, the dominant narrative influences who is seen and assisted in post-disaster response and recovery. These stories also frame discourse surrounding the disaster’s cause or causes, which then impacts our ability to address the real underlying causes in the future.

— Danielle Zoe Rivera, assistant professor of landscape architecture and environmental planning in the College of Environmental Design and director of the Just Environments Lab. Rivera is teaching a course on disaster studies this spring.

You study how environments are managed or mismanaged. What are the mismanaged issues that led to the catastrophe in Los Angeles?

Fire is a normal, recurring event in these ecosystems, and the north-south trending canyons around Malibu have experienced large fires many times in the past century. So these are not novel or unforeseeable events. However, climate change amplifies several of the conditions for fire: low fuel moisture content, high temperatures, extremes of both precipitation (which drives vegetation growth, producing fuels for fires) and longer/hotter dry seasons. With winds upwards of 60–70 mph, there’s basically no way to stop a fire under these conditions.

So the core issue is the presence of so many houses in these areas. Building them has been abetted for decades by zoning, market forces, misleading assurances of and misplaced confidence in fire protection, and the political clout of developers and homeowners. The continued willingness of insurers to write policies has been both a cause and an effect of these drivers, though this may be changing now. Stricter building codes could help reduce risks and impacts, but short of requiring completely fire-proof materials, no code could protect houses from the intensity of fire seen in the past week.

There’s nothing surprising about wealthier neighborhoods being highly exposed to climate change impacts in this case: As Mike Davis pointed out in his 1998 essay, “The Case for Letting Malibu Burn,” past fires have often worked like socio-economic ratchets, pushing out middle-class residents and replacing them with wealthier newcomers who can afford to (re)build.

As far as politics and science, the science around fire in landscapes such as these has been clear for half a century: It is a question of when and how, not if they will burn. A vigorous and proactive program of fuels management (prescribed burning, mechanical thinning, and managed livestock grazing) would be the most scientifically robust management strategy, but existing homes and public sentiments are major obstacles to any such program. These are especially acute in the LA region, with its politically empowered property owners, chaparral vegetation, air quality rules, and Santa Ana winds.

One can be quite confident that the fire conditions of the past week will recur, and very likely get worse. It will be interesting to see if not rebuilding, at least in some of the burned areas, receives any serious public consideration and debate in the months ahead.

—Nathan Sayre, professor of geography

Responses have been condensed and edited for clarity.