FIRE
KNOWS
NO
SEASON
Campus researchers study the science and impact of more intense blazes fueled by climate-driven events
By Jim Washburn
The deadly firestorms that hit Los Angeles County in January will likely scar the Southland’s landscape and psyche for years. The Eaton and Palisades fires and several smaller, concurrent, wind-whipped blazes were a horrific wake-up call that the gap between wilderness and city streets doesn’t mean much in a time of drought and hurricane-strength Santa Anas.
There is also this: For much of the last century, Southern California’s fire season predictably ran from late April into early October. As the 21st century progresses and the climate continues to shift, wildfires have been starting earlier and running later. It’s possible that wildfires are becoming a year-round threat. Before January’s conflagration, there was November’s 20,000-acre Mountain Fire and five lesser ones. Those were scarcely extinguished before December’s Franklin Fire erupted in Malibu. All were fueled by high winds and heavy brush dried by months of dry, hot weather. Acknowledging that combating fires in the state is closer to a 365-day job, Gov. Gavin Newsom announced a package of bills in February to help make 3,000 seasonal Cal Fire firefighters from the Department of Forestry and Fire Prevention full time. And California isn’t an outlier. Nations around the globe have reported record fires and elongated fire seasons. In the U.S. alone, 13 states suffered major fires in November, a time when people once merely worried about their Thanksgiving dinner burning, not their neighborhoods.
“It’s almost certain that we’re going to see lots of progressively big fire years,” says Michael Goulden, UC Irvine professor of Earth system science. He is one of several campus professors who have been studying the rising occurrence and danger of wildfires or their effects upon economies, real estate and other concerns. “Academics are always going to be attracted to important problems, to find ways that can help people,” Goulden says. “There are a lot of good, productive things that can be done regarding wildfires.”
Understanding Wildfires
Goulden, who calls himself an “ecosystem ecologist,” has conducted a significant amount of fieldwork trying to understand how a forest works. “And fire is a big part of that,” he says. “A question we’re still working on is ‘What are the effects the shifting climate has on how a forest functions?’”
Fires have been part of a forest’s life cycle for as long as there have been forests. While once they were caused chiefly by lightning, now human campfire mishaps, downed power lines, arson and other causes have compounded the frequency of fires. And the heat and long periods of drought brought on by a changing climate are turning forests and brushlands into tinderboxes.
The ability to detect fires before they spread is a major consideration. A global project calling for an “intense constellation” of fire-spotting satellites (conventional ones as well as hundreds of 4-cubic-inch “CubeSats,” or miniature satellites, in low orbit) is a long way from being complete, Goulden says. In the meantime, a system of video surveillance cameras seems like a more immediate solution to him.
“They’re already on our mountaintops, often on utility or telecommunications towers,” he notes. “They rotate about once a minute, and when a camera thinks it sees smoke, it’ll stop rotating, figure out if it is smoke, communicate with networked cameras on other mountains to triangulate the location, and notify a technician.”
Another researcher trying to get a better handle on wildfires is Tirtha Banerjee, UC Irvine associate professor of civil and environmental engineering, who says he didn’t start out examining fires. “I studied turbulent fluid mechanics,” Banerjee says. “But I like complexity, and studying the turbulence within fires certainly offers that.”
“My goal now is to develop better models of fire behavior,” he says. “How does a fire interact with the atmosphere? How does it behave in a forested environment versus a grassland environment? There is heat transfer; there is mass transfer. There’s an energy exchange between the vegetation and the atmosphere. How do we encode the physics of these exchange processes?”
Coming up with the data to codify wildfires requires a lot of work out in forests and fields, Banerjee says: “We’re studying not only how a fire flows but things like how firebrands – or wildfire embers – get ejected from a fire and transported very long distances.”
Toward that end, he and his research team conducted a series of nighttime experiments at UC Berkeley’s Blodgett Forest Research Station in the Sierra Nevada mountains. In controlled burns, they ignited piles of wood from ponderosa pine and Douglas fir trees – including branches and pine needles, common fuel in Sierra wildfires. They utilized high-speed imaging instruments to track flame dynamics and the trajectories of the firebrands ejected from the flames and collected them for later laboratory characterization of their size, shape and density. The findings were published in the Physics of Fluids journal in October.
Tirtha Banerjee, UC Irvine associate professor of
civil and environmental engineering
Understanding Wildfires
Goulden, who calls himself an “ecosystem ecologist,” has conducted a significant amount of fieldwork trying to understand how a forest works. “And fire is a big part of that,” he says. “A question we’re still working on is ‘What are the effects the shifting climate has on how a forest functions?’”
Fires have been part of a forest’s life cycle for as long as there have been forests. While once they were caused chiefly by lightning, now human campfire mishaps, downed power lines, arson and other causes have compounded the frequency of fires. And the heat and long periods of drought brought on by a changing climate are turning forests and brushlands into tinderboxes.
The ability to detect fires before they spread is a major consideration. A global project calling for an “intense constellation” of fire-spotting satellites (conventional ones as well as hundreds of 4-cubic-inch “CubeSats,” or miniature satellites, in low orbit) is a long way from being complete, Goulden says. In the meantime, a system of video surveillance cameras seems like a more immediate solution to him.
“They’re already on our mountaintops, often on utility or telecommunications towers,” he notes. “They rotate about once a minute, and when a camera thinks it sees smoke, it’ll stop rotating, figure out if it is smoke, communicate with networked cameras on other mountains to triangulate the location, and notify a technician.”
Another researcher trying to get a better handle on wildfires is Tirtha Banerjee, UC Irvine associate professor of civil and environmental engineering, who says he didn’t start out examining fires. “I studied turbulent fluid mechanics,” Banerjee says. “But I like complexity, and studying the turbulence within fires certainly offers that.”
“My goal now is to develop better models of fire behavior,” he says. “How does a fire interact with the atmosphere? How does it behave in a forested environment versus a grassland environment? There is heat transfer; there is mass transfer. There’s an energy exchange between the vegetation and the atmosphere. How do we encode the physics of these exchange processes?”
Coming up with the data to codify wildfires requires a lot of work out in forests and fields, Banerjee says: “We’re studying not only how a fire flows but things like how firebrands – or wildfire embers – get ejected from a fire and transported very long distances.”
Toward that end, he and his research team conducted a series of nighttime experiments at UC Berkeley’s Blodgett Forest Research Station in the Sierra Nevada mountains. In controlled burns, they ignited piles of wood from ponderosa pine and Douglas fir trees – including branches and pine needles, common fuel in Sierra wildfires. They utilized high-speed imaging instruments to track flame dynamics and the trajectories of the firebrands ejected from the flames and collected them for later laboratory characterization of their size, shape and density. The findings were published in the Physics of Fluids journal in October.
The Palisades Fire, as seen from Santa Monica Beach
The big issue now is the huge subdivisions being built on the urban fringe of wildfire zones. If you look at Orange County, it’s packed with housing from the ocean to the mountains. The increasing fire risk on the fringes means there will be less development.
- Ed Coulson, UC Irvine professor of economics and public policy
The big issue now is the huge subdivisions being built on the urban fringe of wildfire zones. If you look at Orange County, it’s packed with housing from the ocean to the mountains. The increasing fire risk on the fringes means there will be less development.
- Ed Coulson, UC Irvine professor of economics and public policy
The Palisades Fire, as seen from Santa Monica Beach
“We used special cameras to track ember particles,” Banerjee explains. “The embers can behave quite differently and are a major piece of uncertainty in fire behavior models. This kind of research can help us understand ember traveling characteristics and where they might land. Then the next step is to help understand what we can do to make them less of a problem.” In the Palisades and Eaton fires, it was reported that embers traveled miles carried by gusts of 80 to 100 mph winds, fueling the historic destruction.
Banerjee and Goulden are both interested in what the state of California is calling its Roadmap to a Million Acres. By the end of 2025, the initiative aims to be clearing a million acres a year of forest floors’ dead wood, pine needles and other accumulated items that feed fires – using prescribed fires, wood utilization and regulatory streamlining, among other methods.
Goulden says, “It’s going to be expensive, costing thousands of dollars an acre. But strategically placed, especially near communities, I think it will be very effective.”
Banerjee elaborates, “What we don’t want is the extreme fires, which happen when an extreme amount of fuel has been allowed to build up on the ground. The flames from that are very tall, and it’s hard to predict their behavior.”
“Wildfires are getting larger and more complex,” he adds, “and our development patterns in the wildland-urban interface mean that these blazes are causing damage that’s directly impacting people living in these areas, both financially and in terms of personal safety.”
The Eaton Fire (Altadena aftermath above) both erupted on Jan. 7, killing at least 29 people and destroying or damaging over 18,000 structures combined – becoming the most destructive wildfires ever recorded in Southern California.
The Wildland-Urban Interface
A major concern about wildfires is that the ever-growing demand for housing has pushed developers to build tracts that encroach upon flammable land. That proximity has come to be called the wildland-urban interface.
Goulden says that old-school methods of fire intervention such as firebreaks – a swath of bare land separating nature from homes and other structures – can slow a fire’s advance. Landowner assistance in such preventive measures is another prong of California’s Million Acres initiative. And Goulden notes that “utility companies are also clearing and treating areas along their power lines, which is smart since they have been the source of so many fires.”
These clearings are of less use when high winds are driving the flames and when gusts send embers airborne to land on roofs as far as 2.5 miles away. Goulden says toughened building codes are taking that danger into account, stressing fire-resistant roofs and deck materials in high-risk areas.
And what about those houses? Jan Brueckner, UC Irvine Distinguished Professor of economics, makes no claim to be conversant in wildfire dynamics but says, “I know what’s happening in the insurance world and in parts of the real estate market, and fires certainly have an influence there.”
“The big issue now is the huge subdivisions being built on the urban fringe of wildfire zones,” he says. “If you look at Orange County, it’s packed with housing from the ocean to the mountains. The increasing fire risk on the fringes means there will be less development.”
Along with the likelihood of that, Brueckner says, insurance companies’ soaring rates or refusals to insure properties near a wildland-urban interface will result in fewer fire-razed homes being rebuilt. “In many cases,” he says, “only those wealthy enough to self-insure will be able to afford to rebuild.”
Both homeowners and renters who lose their dwellings in a fire may have trouble finding a temporary replacement, says Ed Coulson, UC Irvine professor of economics and public policy, as well as director of The Paul Merage School of Business’ Center for Real Estate. “The previous time fires hit Ventura, a couple of years ago, people who had lost their homes didn’t want to leave the area, so the price of temporary housing went up. That had ripple effects throughout the housing market.”
Along with the grievous damage to homes in wildland-urban interface areas, Brueckner says, attention needs to be given to those living in more rustic locales. “There may be an assumption that people in wilderness areas are living in custom-built dream homes,” he says. “Take a drive on the Ortega Highway – where many homes were destroyed or damaged in this past September’s Airport Fire – and you’ll see low-income communities and how deeply they were affected.”
Ed Coulson, UC Irvine professor of
economics and public policy
The January fires, which damaged or destroyed over 18,000 structures, also impacted many elderly and longtime homeowners, as well as renters. The rebuilding process will take time to determine. The state insurance commissioner has called for a mandatory one-year moratorium on insurance nonrenewals, while the California Fair Plan, an insurer of last resort for those who cannot get private fire insurance, has assessed that it needs $1 billion more from insurers to pay out claims.
As Brueckner noted, even before these catastrophic fires, obtaining insurance had become a major impediment to rebuilding in fire-struck areas. Rising rates had priced some homeowners out of the market, while Coulson points out that insurance companies sustained large losses due to fires in recent years, leading some to abandon offering coverage in high-risk areas.
In December, the California Department of Insurance issued regulations requiring insurers to increase their coverage in fire-prone areas. In return, Coulson says: “The new regulations will allow home insurance premiums to be based not just on historical loss data, but also on projections of future losses. This change has been long sought by insurers, given evolving climatic conditions.”
“This is a good development,” he adds. “An important aspect of the new regulatory structure is the requirement that insurers hold a specific number of their policies in the high-risk areas they had evidently been avoiding. This new requirement provides incentives for insurers to actually compete for policies in these areas.”
The Wildland-Urban Interface
A major concern about wildfires is that the ever-growing demand for housing has pushed developers to build tracts that encroach upon flammable land. That proximity has come to be called the wildland-urban interface.
Goulden says that old-school methods of fire intervention such as firebreaks – a swath of bare land separating nature from homes and other structures – can slow a fire’s advance. Landowner assistance in such preventive measures is another prong of California’s Million Acres initiative. And Goulden notes that “utility companies are also clearing and treating areas along their power lines, which is smart since they have been the source of so many fires.”
These clearings are of less use when high winds are driving the flames and when gusts send embers airborne to land on roofs as far as 2.5 miles away. Goulden says toughened building codes are taking that danger into account, stressing fire-resistant roofs and deck materials in high-risk areas.
And what about those houses? Jan Brueckner, UC Irvine Distinguished Professor of economics, makes no claim to be conversant in wildfire dynamics but says, “I know what’s happening in the insurance world and in parts of the real estate market, and fires certainly have an influence there.”
“The big issue now is the huge subdivisions being built on the urban fringe of wildfire zones,” he says. “If you look at Orange County, it’s packed with housing from the ocean to the mountains. The increasing fire risk on the fringes means there will be less development.”
Along with the likelihood of that, Brueckner says, insurance companies’ soaring rates or refusals to insure properties near a wildland-urban interface will result in fewer fire-razed homes being rebuilt. “In many cases,” he says, “only those wealthy enough to self-insure will be able to afford to rebuild.”
Both homeowners and renters who lose their dwellings in a fire may have trouble finding a temporary replacement, says Ed Coulson, UC Irvine professor of economics and public policy, as well as director of The Paul Merage School of Business’ Center for Real Estate. “The previous time fires hit Ventura, a couple of years ago, people who had lost their homes didn’t want to leave the area, so the price of temporary housing went up. That had ripple effects throughout the housing market.”
Along with the grievous damage to homes in wildland-urban interface areas, Brueckner says, attention needs to be given to those living in more rustic locales. “There may be an assumption that people in wilderness areas are living in custom-built dream homes,” he says. “Take a drive on the Ortega Highway – where many homes were destroyed or damaged in this past September’s Airport Fire – and you’ll see low-income communities and how deeply they were affected.”
The January fires, which damaged or destroyed over 18,000 structures, also impacted many elderly and longtime homeowners, as well as renters. The rebuilding process will take time to determine. The state insurance commissioner has called for a mandatory one-year moratorium on insurance nonrenewals, while the California Fair Plan, an insurer of last resort for those who cannot get private fire insurance, has assessed that it needs $1 billion more from insurers to pay out claims.
As Brueckner noted, even before these catastrophic fires, obtaining insurance had become a major impediment to rebuilding in fire-struck areas. Rising rates had priced some homeowners out of the market, while Coulson points out that insurance companies sustained large losses due to fires in recent years, leading some to abandon offering coverage in high-risk areas.
In December, the California Department of Insurance issued regulations requiring insurers to increase their coverage in fire-prone areas. In return, Coulson says: “The new regulations will allow home insurance premiums to be based not just on historical loss data, but also on projections of future losses. This change has been long sought by insurers, given evolving climatic conditions.”
“This is a good development,” he adds. “An important aspect of the new regulatory structure is the requirement that insurers hold a specific number of their policies in the high-risk areas they had evidently been avoiding. This new requirement provides incentives for insurers to actually compete for policies in these areas.”
Watching Global Patterns
Ever-growing wildfires are certainly not an exclusively Southern California phenomenon, and one may learn from watching how policies and regulations around the world are influencing fire patterns.
When Eve Darian-Smith, UC Irvine Distinguished Professor and chair of global and international studies, visited her native Australia five years ago to see her family, she landed in an extreme environment. “I came home to possibly the most horrific fire the country had ever experienced,” Darian-Smith says. “It burned much of the continent, destroyed towns and decimated the koala population.”
She adds, “Then I came back to the U.S., and there were major fires here, while fires were also burning across the Brazilian Amazon rainforests.” This experience motivated her recent research, Darian-Smith says: “We always think of fires as discrete events because they’re so immediate and site-specific, but it got me wondering why we’re talking about fires as one-off events when there’s a pattern of increasingly bigger, more frequent and more dangerous fires happening around the world.”
The result of her wondering was the 2022 Stanford University Press book Global Burning: Rising Antidemocracy and the Climate Crisis. It explores how environmental challenges intersect with broader global trends, such as government structures and policies that may prioritize short-term economic gains over long-term ecological sustainability.
“Brazil’s then-president, Jair Bolsonaro, had basically declared it open season on burning the Amazon to clear it for mining and other businesses,” Darian-Smith says. “Australia’s prime minister served the oil and mining industries, and the fires were directly linked to mining, which had destroyed huge swaths of land and contributed to declining water tables, making it an even drier continent. Meanwhile, the U.S. was rolling back 50 years of Environmental Protection Agency regulations and taking us out of the Paris Agreement on climate change, and the fires and floods just keep on coming.”
She worries it isn’t just koalas that are becoming an endangered species, saying: “Climate scientists are increasingly under attack, as is anyone who is pointing out the political implications of climate crises.”
And as wildfires move ever closer to becoming year-round, researchers underscore that just as fire knows no season, it also knows no politics. For them, they emphasize, it’s a race to better understand, mitigate and improve recovery from such events – and potentially help prevent such devastation from occurring again.
“There is still so much for us to learn,” Banerjee says. “How do we come up with fire management scenarios that are more scientifically informed? How can we better predict the flow of a fire? How far will firebrands go in these more powerful winds? How do we get the optimum protection from firebreaks? This isn’t just scientific curiosity. There are lives at stake.”
Watching Global Patterns
Ever-growing wildfires are certainly not an exclusively Southern California phenomenon, and one may learn from watching how policies and regulations around the world are influencing fire patterns.
When Eve Darian-Smith, UC Irvine Distinguished Professor and chair of global and international studies, visited her native Australia five years ago to see her family, she landed in an extreme environment. “I came home to possibly the most horrific fire the country had ever experienced,” Darian-Smith says. “It burned much of the continent, destroyed towns and decimated the koala population.”
She adds, “Then I came back to the U.S., and there were major fires here, while fires were also burning across the Brazilian Amazon rainforests.” This experience motivated her recent research, Darian-Smith says: “We always think of fires as discrete events because they’re so immediate and site-specific, but it got me wondering why we’re talking about fires as one-off events when there’s a pattern of increasingly bigger, more frequent and more dangerous fires happening around the world.”
The result of her wondering was the 2022 Stanford University Press book Global Burning: Rising Antidemocracy and the Climate Crisis. It explores how environmental challenges intersect with broader global trends, such as government structures and policies that may prioritize short-term economic gains over long-term ecological sustainability.
“Brazil’s then-president, Jair Bolsonaro, had basically declared it open season on burning the Amazon to clear it for mining and other businesses,” Darian-Smith says. “Australia’s prime minister served the oil and mining industries, and the fires were directly linked to mining, which had destroyed huge swaths of land and contributed to declining water tables, making it an even drier continent. Meanwhile, the U.S. was rolling back 50 years of Environmental Protection Agency regulations and taking us out of the Paris Agreement on climate change, and the fires and floods just keep on coming.”
She worries it isn’t just koalas that are becoming an endangered species, saying: “Climate scientists are increasingly under attack, as is anyone who is pointing out the political implications of climate crises.”
And as wildfires move ever closer to becoming year-round, researchers underscore that just as fire knows no season, it also knows no politics. For them, they emphasize, it’s a race to better understand, mitigate and improve recovery from such events – and potentially help prevent such devastation from occurring again.
“There is still so much for us to learn,” Banerjee says. “How do we come up with fire management scenarios that are more scientifically informed? How can we better predict the flow of a fire? How far will firebrands go in these more powerful winds? How do we get the optimum protection from firebreaks? This isn’t just scientific curiosity. There are lives at stake.”
Watching Global Patterns
Ever-growing wildfires are certainly not an exclusively Southern California phenomenon, and one may learn from watching how policies and regulations around the world are influencing fire patterns.
When Eve Darian-Smith, UC Irvine Distinguished Professor and chair of global and international studies, visited her native Australia five years ago to see her family, she landed in an extreme environment. “I came home to possibly the most horrific fire the country had ever experienced,” Darian-Smith says. “It burned much of the continent, destroyed towns and decimated the koala population.”
She adds, “Then I came back to the U.S., and there were major fires here, while fires were also burning across the Brazilian Amazon rainforests.” This experience motivated her recent research, Darian-Smith says: “We always think of fires as discrete events because they’re so immediate and site-specific, but it got me wondering why we’re talking about fires as one-off events when there’s a pattern of increasingly bigger, more frequent and more dangerous fires happening around the world.”
The result of her wondering was the 2022 Stanford University Press book Global Burning: Rising Antidemocracy and the Climate Crisis. It explores how environmental challenges intersect with broader global trends, such as government structures and policies that may prioritize short-term economic gains over long-term ecological sustainability.
“Brazil’s then-president, Jair Bolsonaro, had basically declared it open season on burning the Amazon to clear it for mining and other businesses,” Darian-Smith says. “Australia’s prime minister served the oil and mining industries, and the fires were directly linked to mining, which had destroyed huge swaths of land and contributed to declining water tables, making it an even drier continent. Meanwhile, the U.S. was rolling back 50 years of Environmental Protection Agency regulations and taking us out of the Paris Agreement on climate change, and the fires and floods just keep on coming.”
She worries it isn’t just koalas that are becoming an endangered species, saying: “Climate scientists are increasingly under attack, as is anyone who is pointing out the political implications of climate crises.”
And as wildfires move ever closer to becoming year-round, researchers underscore that just as fire knows no season, it also knows no politics. For them, they emphasize, it’s a race to better understand, mitigate and improve recovery from such events – and potentially help prevent such devastation from occurring again.
“There is still so much for us to learn,” Banerjee says. “How do we come up with fire management scenarios that are more scientifically informed? How can we better predict the flow of a fire? How far will firebrands go in these more powerful winds? How do we get the optimum protection from firebreaks? This isn’t just scientific curiosity. There are lives at stake.”
UC Irvine Magazine is produced by the Office of Strategic Communications & Public Affairs.
To contact the editor, email ucimagazine@uci.edu.