In July 2021, smoke from California’s Dixie Fire, the second largest in the state’s history, combined with smoke from fires in the American West and Canada, traveled thousands of miles to New York and other parts of the East Coast, triggering air-quality alerts. It was an alarming message for people a continent away from the flames that the environmental fallout from climate change does not respect state lines.
California is prone to both droughts and floods, but climate change is sending those natural cycles into overdrive. In the last decade, record-breaking heat waves have combined with severe and prolonged droughts to disastrous effect. Eight of the state’s top 10 largest wildfires took place in the past five years, exacting a huge personal and financial toll on people, homes, farms, and tourism.
For Stanford Law faculty, students, and alumni who study water, wildfire, and smoke, California is already at a crisis point, giving their research new urgency. But their work, often bringing together experts from multiple disciplines across campus, also offers a path forward to mitigate the rising risks, if policy and management can shift dramatically—and soon.
Water and Drought
In the early 20th century, Buzz Thompson’s grandfather was a farmer in the Owens Valley when the Los Angeles Aqueduct was constructed, diverting water from the Owens River to the rapidly expanding city 200 miles to the south. The project effectively wiped out agriculture in the region, leaving valley residents with a sense that they’d lost control of their future, explains Thompson, who is the Robert E. Paradise Professor of Natural Resources Law at Stanford Law School, founding director of the Stanford Woods Institute for the Environment, and director of its Water in the West program.
“Water is the most precious resource we have,” says Thompson, JD/MBA ’76 (BA ’72), a global water and environmental law expert. “Water in the western U.S. has really driven and defined its history.”
In his forthcoming book, The Business of Water, Thompson details the water crisis that recently gripped Cape Town, South Africa. To meet the needs of its growing population, Cape Town relied on local reservoirs combined with a much-admired water conservation program. But it failed to plan adequately for climate change. A series of severe dry years—now much more likely in a warming world—hit from 2015 to 2018, sending area reservoirs to dangerously low levels and triggering increasingly drastic water restrictions. Thompson took a class of Stanford Law students to Cape Town in 2019 to learn the lessons of what the region called “Day Zero,” the day it almost ran out of water.
As Thompson and his students discovered, Cape Town isn’t an arid outlier, and its brush with catastrophe offers a cautionary tale for the American West. Many cities in California actually receive less rain in an average year than Cape Town—making Day Zero a wake-up call that cities must prepare for unusually severe droughts, which are expected to become more common in the face of climate change.
Illustration by Ryan Johnson
Droughts have already devastated certain areas of the state, particularly disadvantaged rural communities, says Thompson. “During the 2014 drought farmers in the Central Valley had been pumping more and more groundwater to irrigate their crops, and groundwater tables went way down. Cities with shallow wells found their wells went dry.”
Balancing the water needs of the state’s varied constituents, from vineyards to cities to rural towns, is a herculean task.
So is ensuring careful management of the state’s groundwater. In a recent report from Stanford’s Water in the West and The Nature Conservancy, Thompson and his colleagues describe groundwater as “the resilience in California’s water supply,” with 85 percent of Californians depending on it for at least some of their water. The Sustainable Groundwater Management Act (SGMA), passed in 2014, places limits on groundwater pumping and is considered a major step forward by the state to preserve this vital resource. However, Thompson and his colleagues see significant gaps in the law, which allow continued overuse in unregulated sources and areas.
“Unregulated pumping has the potential to exacerbate threats to drinking water, increase wildfire risk, and compromise surface water rights and ecosystems,” according to the report.
The state also must brace itself for “water whiplash” as it swerves between prolonged dry spells to very wet, flood-prone periods. Wild swings in precipitation have always been a part of the state’s highly variable climate. During the Civil War, Thompson points out, epic floods in 1861-62 gave way to intense drought in 1862-64. These extremes will only get worse with climate change.
“We’ll have more droughts and those droughts will often be longer and more intense than we’ve seen before,” he says. “Going forward, we also know that virtually every drought will be hotter than our historically average temperature. That’s a real problem.”
California will need to be able to store water during wet episodes, Thompson says, and better manage and account for very limited supplies during parched years.
But the future is already here. California suffered the longest drought in recorded history from 2011 to 2017. Only four years later, Thompson notes, the state is mired in yet another severe drought. For much of this year, 100 percent of the state suffered from drought conditions, with a quarter or more in “exceptional drought,” with more severe water shortages.
Drought began creeping back onto California maps in January 2020, but back-to-back dry years—combined with record-breaking hot temperatures—have been a game changer. By autumn 2021, the consequences were glaring: reservoirs at or near record lows, a key hydroelectric plant at Lake Oroville shuttered for the first time, wells running dry, forests burning, smoke-choked skies, and fish stocks in peril.
Thompson raises another concern: He worries that California does not have a firm grasp of how much water it has and who is taking water from what sources. Illegal diversions of water from rivers and streams are the norm. It’s essential, he says, that the California Water Resources Control Board, which oversees these issues, has all the authority it needs to regulate water during droughts. For example, the state must ensure that all diversions are legal and reported and that all rivers and streams are gauged.
Equally critical is finding reliable ways to store water in a hot and volatile climate and capturing as much water as possible during major storms for subsequent use. Thompson believes the most promising option for storing excess water, when the rains do come, is in natural underground aquifers—an approach that has already been embraced in many regions of the state. “Surface reservoirs are costly and often face environmental opposition,” Thompson notes. “Aquifers are free and readily available.”
But climate change is threatening our water supply in another way—by contributing to extreme wildfires that are burning the forests that make up the state’s watersheds.
Forests in Flames
In “normal” times, the snowpack of the Sierra Nevada range provides the state with a natural water storage system, gradually releasing water through the spring and well into the summer months. Damp, high-elevation areas also serve as a natural fire break. Until they don’t.
Most of the destructive California wildfires in 2021 burned through forests in the Sierra and Cascades, which were tinder dry because of drought, low snowpack, and scorching summer heat waves—all amplified by climate change. Many burned at high intensity, inflicting damage to forest ecosystems and the communities within them. The nearly 1-million-acre Dixie Fire became the first fire in recorded history to burn from one side of the Sierra to the other.
These increasingly intense fires are also the result of decades of accumulated fuel that is available to burn, according to Deborah Sivas, the Luke W. Cole Professor of Environmental Law at Stanford Law, founding director of the Environmental Law Clinic, director of the Environmental and Natural Resources Law and Policy Program, and a senior fellow at Stanford Woods Institute for the Environment.
One of the state’s top environmental litigators, Sivas, JD ’87, who was a 3L when Thompson started teaching at Stanford Law and took a class with him, is uniquely positioned to navigate California’s escalating wildfire crisis, where solutions are hampered by conflicting interests among environmental organizations, the U.S. Forest Service, and communities at increased risk from destructive fires.
“Forest management remains a highly controversial subject, but there is an emerging consensus on all sides that our forests have been relatively poorly managed in the past,” says Sivas. “The big challenge today is how we move forward.”
In an article for The Regulatory Review, written during California’s record-breaking 2020 wildfire season, Sivas details the problems plaguing the state’s forests—all of which came home to roost again this year. “Historic fire suppression and unsustainable logging practices have resulted in too much vegetative understory, too many even-aged stands, and too few resilient, old-growth trees that protect forests from catastrophic wildfire,” she writes.
These long-standing issues are now tightly woven with climate change. “The result is what climate scientists call a positive feedback loop,” Sivas continues, “a vicious cycle where high-intensity fire in climate-stressed forests releases carbon stored in living trees to the atmosphere, thereby hastening even more global warming.”
In September 2021, another devastating wildfire season, Governor Gavin Newsom signed a $15 billion climate resilience package in Sequoia National Park, where the thousand-year-old trees faced destruction for a second year in a row. He specifically highlighted forest management in a press conference unveiling the new legislation, which allocates over $1 billion to wildfire-related projects.
“It’s been a century-plus where we haven’t been actively managing our forests,” he said, while announcing a commitment to double the amount of land that will be managed in partnership with the federal government.
That partnership is key, because federal agencies manage 57 percent of the state’s forested land, with only 3 percent controlled by the state and the remainder in private hands.
“The Forest Service is not really adapting fast enough to deal with the acceleration of the problem,” Sivas says. She emphasizes that the agency still leans too heavily on fire suppression and is not fully embracing prescribed fire and managed fire, in which fires are monitored but not immediately extinguished so they can burn naturally in remote areas for ecological purposes.
“The National Park Service, in my mind, provides a better model for managing our federal forestlands,” Sivas explains. “Imbued with a land stewardship ethos, the Park Service more effectively uses a combination of prescribed burning and native habitat restoration to bring these ecosystems back into balance.”
At the state level, there has been recent progress on this front. Two bills, SB332 and AB642, are expected to remove liability obstacles for prescribed burning and to increase training for people who manage prescribed fires. Michael Wara, JD ’06, director of the Climate and Energy Policy Program and a senior research scholar at the Stanford Woods Institute for the Environment, worked with State Senator Bill Dodd, the Karuk Nation, and others to pass SB332.
The legislation was also informed by research conducted in the Stanford Law policy practicum Smoke, an interdisciplinary research project with students from areas as diverse as computer science, the School of Medicine, Stanford Law, and the School of Earth, Energy & Environmental Sciences. Wara suggested co-teaching the practicum with Sivas, who was his teacher when he was a law student. She agreed.
But more drastic steps may be needed, such as reimagining the U.S. Forest Service or creating a new agency dedicated to wildfire resilience, employing a vast workforce in forest communities impacted by the decline of the timber industry. But, Sivas cautions, the people they’ve been working with want to see funds put into restoration activity that doesn’t involve cutting lots of trees.
“The kind of people that we need to restore these landscapes have historically had jobs out on the land,” she says. “That’s how you are going to put people to work who have lost jobs from these extraction industries.”
Rediscovering Native Practices
Big Basin Redwoods, California’s oldest state park, was devastated by the August 2020 CZU Lightning Complex Fire, which incinerated 97 percent of the park. While many of the ancient redwoods managed to survive flames, which reached an estimated 100 feet, the damage to some trees is telling.
“When you look at the fire scars on a typical redwood tree in Big Basin, you’ll see signs of fires every five to 10 years up to about the year 1870. And then there are no burn scars until 2020,” says Wara.
Wara explains that the burn scars on the giant redwoods in Big Basin Redwoods State Park disappeared in 1870 for two reasons: The Native Americans were forcibly removed from their lands while the practices of cultural and controlled burning of the undergrowth in the forest were prohibited by both the state and federal governments. Compared with the thick, overgrown forests of today, California’s forests looked markedly differently in the 1800s.
“You could ride a horse through the forests of the Sierra Nevada. There were open meadows under giant, very mature conifers. There were long lanes and open pathways through the forests,” describes Wara.
Mounting evidence suggests that California’s massive wildfires release far more harmful smoke than the cultural burning once practiced by Native tribes.
Students in the practicum have been exploring regulatory obstacles to an expansion of cultural and prescribed burning in California and began developing a simplified air-quality health benefits model to estimate the potential public health and economic advantages of better fuels management. They’ve met with several guest speakers, including Bill Tripp, deputy director of eco-cultural revitalization for the Karuk Tribe’s Department of Natural Resources and an advocate for a return to controlled burns—for environmental as well as cultural reasons.
“Bill explained that without cultural burning, the reeds that members of the Karuk Tribe use to weave baskets don’t grow properly, and the acorns that many people use to make a staple food become infected with insects. So, controlled burning of the forests is important to their livelihoods and traditions too,” explains Ada Statler, JD/MS ’22 (BS ’18).
Statler and other law students have been exploring potential new policy approaches to streamlining the approval process for prescribed burning projects. Unlike wildfire emissions, prescribed fire is regulated, requiring burn permits and sometimes lengthy environmental reviews under the California Environmental Quality Act (CEQA).
“We’re working to lower some of the burdensome obligations that come with CEQA while maintaining the protections of CEQA,” says Statler. “It’s a delicate needle to thread.”
Wildfire Smoke Deaths
But a shift to better forest management is a long-term goal, and high fire risk won’t disappear overnight.
“Even if we had a radical management change, it is going to take many years to get the forests back to some semblance of health,” Sivas says. “In the meantime, we need to focus as a state on not just lowering emissions, but also reducing California’s vulnerable exposure to wildfire smoke,” Wara notes.
Wildfire smoke is not only contributing significantly to carbon dioxide emissions but is now also considered a serious health threat. Stanford research co-authored by Wara estimates that 2020’s massive wildfires may have caused up to 3,000 deaths from smoke exposure via fine particle pollution.
And this is where PhD students from computer science and earth sciences enrolled in the Smoke practicum come in. With experience in atmospheric modeling and machine learning, they can build models to help the team assess various scenarios—for instance, the health effects of smoke in air over a 10-year span when there have been prescribed burns compared to periods with few prescribed burns and massive wildfires.
“This kind of modeling hasn’t been done before. And it’s very important,” says Wara. “The health dangers of wildfire smoke are very, very serious. One of the biggest and least well-known risks is to pregnant women and their unborn babies. We are seeing significantly higher miscarriage rates and premature births during smoke events in California. We need to find ways to lessen the severity of big, smoky wildfires. It really is an existential issue for the state.”
The Brunt of Smoke Exposure
Hardest hit by the impact of wildfire smoke are the Central Valley’s agricultural regions—and outdoor workers.
“These communities are just getting hammered by smoke from the big wildfires,” Sivas says.
The Clean Air Act regulates industrial emissions—not wildfire smoke—and yet research by Wara and his co-authors shows that smoke from megafires threatens to unwind decades of progress toward improved air quality.
While the long-term goal is building forest resilience through ecologically appropriate management, Sivas suggests we need to protect affected communities in the short term. For instance, analysis coming out of the policy practicum may provide empirical support for directing resources toward air-filter systems for public schools and low-income residences in vulnerable communities.
And on the forest management side, Sivas believes that resources are most effectively spent on protecting homes from fire risks and on prescribed burning and vegetation removal in and around at-risk forest communities, rather than continuing to log in remote landscapes. “Money raining down from Sacramento isn’t necessarily the answer,” she says. “If there is no leadership in a policy direction, it will get spent on what it is already being spent on.”
During last summer’s Dixie Fire, much of the Feather River watershed, which feeds California’s second-largest reservoir at Lake Oroville, burned. Thompson sees the state’s water resilience as directly tied to the health of its forests—and its native fish.
“Fish in a river are similar to canaries in a coal mine,” says Thompson. “Declining fish numbers are a sure sign of an unhealthy waterway. For anyone interested in how climate change might negatively impact us in the future, the first place to look is water.”
Unhealthy waterways, drought, and climate change are impacting the state, leading to—and the result of—more frequent and intense wildfires. Thompson says that curbing global carbon emissions is “exceptionally important” but that some warming is already baked into the system. That means California will need to act quickly to adapt and apply solutions, drawing upon the state’s best scientists and experts.
To that end, the Smoke team is preparing to brief California legislative and executive branch staff, as well as California congressional staff about their findings. It’s the kind of proactive research the state will need more of as it confronts rapidly escalating water and wildfire challenges amid rising global temperatures. SL
Diana Leonard is a science journalist and frequent contributor to the Washington Post.