The science behind the West Coast fires

A study led by Stanford scientists shows autumn days with extreme fire weather have more than doubled in California since the early 1980s due to climate change.

The new normal for Western wildfires is abnormal, with increasingly bigger and more destructive blazes.

Stanford climate and wildfire experts discuss extreme weather’s role in current and future wildfires, as well as ways to combat the trend toward bigger, more intense conflagrations.

“Humans are ingenious at managing climate risk, but our systems are built around the historical climate,” climate scientist Noah Diffenbaugh told The Washington Post. “Systems that were built for the old climate are being stressed in a new way.”

(Image credit: Sheila Sund / Flickr)

“In a changing climate it’s not just about continuing to manage the risk of ignition. We also need to recognize that we are dealing with biome shifts that will occur through time," said Chris Field, director of Stanford's Woods Institute for the Environment. Read more in the National Geographic article, "How much are beetles to blame for the 2020 fires?"

“The forests are alive. They’re growing and dying and regrowing,” says Michael Wara, director of the climate and energy policy program at the Woods Institute for the Environment. “That’s really different than carbon that was buried 50 million years ago under the earth that we are unearthing and burning. I think it’s not helpful to compare the two. It’s a misdirection.”

Immune markers and pollutant levels in the blood indicate wildfire smoke may be more harmful to children’s health than smoke from a controlled burn.

What does smoke inhalation do to my health? What’s the evidence that these are caused by climate change? Here is how some Stanford experts answer and continue to tackle these complex concerns.

California’s massive wildfires bring a host of health concerns for vulnerable populations, firefighters and others. Kari Nadeau and Mary Prunicki of Stanford’s Sean N. Parker Center for Allergy and Asthma Research discuss related threats, preparedness and ongoing research.

"Only certain masks are effective during wildfires, while a range of face coverings may help prevent coronavirus transmission," Stanford researchers write in Environmental Research Letters. Drawing on human behavior studies and past responses to epidemics and wildfire smoke, the scientists recommend ways to communicate mask-use guidance more effectively.

As wildfires become more frequent due to climate change, the increasing amounts of smoke may harm Americans nearly as much as rising temperatures, according to a working paper by Stanford environmental economist Marshall Burke and colleagues. “We hadn’t even thought of that as a key part of the climate impact in this country,” Burke told Bloomberg.

Marshall Burke, an economist at Stanford, has found that, across California, as the number of smoke days has risen over the past 15 years, it has begun to reverse some of the gains that the state had made in cleaning up its air from conventional sources of pollution.

Wildfire smoke will be one of the most widely felt health impacts of climate change throughout the country, but U.S. clean air regulations are not equipped to deal with it. Stanford experts discuss the causes and impacts of wildfire activity and its rapid acceleration in the American West.

Warnings of another severe wildfire season abound, as do efforts to reduce the risk of ignition. Yet few are taking precautions against the smoke. Stanford experts advise on contending with hazardous air quality.

Smoke from wildfires – particularly those that burn manmade structures – can significantly increase the amount of hazardous toxic metals present in the air, sending up plumes that can travel for miles, a new study from the California Air Resources Board has suggested. "No one is protected," said Mary Prunicki of Stanford’s Sean N. Parker Center for Allergy and Asthma Research.

Interviews with Northern California residents reveal that social norms and social support are essential for understanding protective health behaviors during wildfire smoke events – information that could be leveraged to improve public health outcomes.

Smoke from wildfires may have contributed to thousands of additional premature births in California between 2007 and 2012. The findings underscore the value of reducing the risk of big, extreme wildfires and suggest pregnant people should avoid very smoky air.

Analysis by Stanford researchers suggests California needs fuel treatments – whether prescribed burns or vegetation thinning – on about 20 million acres or nearly 20 percent of the state’s land area.

Scientists and engineers worked with state and local agencies to develop and test a long-lasting, environmentally benign fire-retarding material. If used on high-risk areas, the treatment could dramatically cut the number of fires that occur each year.

Experts with Stanford's Woods Institute for the Environment discuss strategies for managing wildfire risks, including incentive structures, regulations, partnerships and financing.

"In talking about risks and policy prescriptions, we need to separate out wildfires at the wildland-urban interface – those that put people and communities at most risk – from fires that historically have burned through our remote forestlands," said Deborah Sivas, Director of Stanford’s Environmental Law Clinic. 

"Successful wildfire preparedness begins with a clear strategy and accountability for outcomes," writes Michael Wara, director of the Climate and Energy Policy Program at Stanford's Woods Institute for the Environment.

"As fires burn with greater magnitude and frequency, the cost of fighting them is increasingly borne by money earmarked for prevention," writes Bill Lane Center for the American West writer in residence Felicity Barringer.

Stanford experts review recent trends in wildfire activity, quantify how the smoke from these wildfires is affecting air quality and health across the U.S. and discuss what policymakers can do to help reduce wildfire risk.

Heat waves that could melt the fat in uncooked meat until it would “run away in spontaneous gravy.” Forests that turned abruptly into “great sheets of flame.” These are some of the realities of life in California noted by the botanist William Brewer in 1860, and surfaced in an essay for The New Yorker by Stanford Classics professor Ian Morris about being evacuated from his home in the Santa Cruz mountains.

According to Morris, "Before Europeans came, Native Californians had found ways to cope with this reality. Many moved seasonally, partly to avoid forest fires. As much as one-sixth of the state was deliberately burned each year." Not many people lived in places like the Santa Cruz Mountains until the 1870s. Since then, Morris wrote, the "quiet migration of hundreds of thousands of nature lovers has created one of the most unnatural landscapes on Earth."

"We need programs that emphasize and support herd immunity from fires," Rebecca Miller, a PhD student in the Emmet Interdisciplinary Program in Environment and Resources, told Mic. Rebuilding efforts after a fire, she added, ought to recognize that once-burned neighborhoods are likely to burn again.

Fire burned the Coffey Park neighborhood of Santa Rosa, Calif. in October 2017. (Image credit: Sgt. 1st Class Benjamin Cosse / California National Guard)

Stanford researchers have developed a deep-learning model that maps fuel moisture levels in fine detail across 12 western states, opening a door for better fire predictions.

Engineers at Stanford have used X-ray CT scans, more common in hospital labs, to study how wood catches fire. They’ve now turned that knowledge into a computer simulation to predict where fires will strike and spread.

Find experts, events, information about ongoing research projects and more.

Read the latest wildfire coverage from Stanford News.