Updated at 12:47 p.m. ET on September 8, 2021.
After this summer’s first searing heat wave baked the Pacific Northwest, the environmental scientist Robert Rohde posted an unusual observation on Twitter.
Looking through a report that analyzed temperature patterns for the region over the past 70 years, he noted, “the heatwave was statistically ‘impossible.’” Obviously, the heat wave wasn’t literally impossible, given that, after all, it happened. But the broiling temperature that the Northwest reached—108 degrees Fahrenheit at one point in Seattle, 121 degrees in British Columbia—was so far beyond the observed experience, he explained, that it exceeded even statistical models’ outmost potential extremes for the area.
A few weeks later, I caught up with Rohde, the lead scientist for Berkeley Earth, a nonprofit research group that analyzes current and historical climate data, via Zoom from Zurich, where he’s now living. He reiterated that the Northwest temperatures reached this summer were outside the boundaries “of what we thought was possible.”
Rohde allowed that such seemingly impossible events do in fact “sometimes” occur. But, he told me, it’s much more common for extreme events to match a rare high point with at least some historic precedent—hence the idea, say, of the thousand-year flood. Truly unprecedented events that shatter any previous experience, he said, have been much rarer. “It is not that common,” he said drily, “to find results that look impossible.”
Rohde offered two explanations for such a unique event. The heat wave, he suggested, might have represented a meteorological black swan: “a rare dynamical interaction that has always been possible, but so rare that in 70 years of data we never observed a weather pattern that was qualitatively similar.” But there was also, he said, a second, “scarier” explanation for the surge, which led to hundreds of excess deaths across Washington and Oregon, as well as mass die-offs for shellfish that were literally baked in their shells: The climate is changing in ways we don’t entirely understand. “Once in a while, Mother Nature can throw surprises at us, and what we have experienced in the past is not always a good predictor of the future,” he told me. “And climate models are telling us that some things that are coming are not necessarily what we are familiar with.”
Across the western United States, 2021 is the year when the unimaginable became the unavoidable. The severity of the threat has been matched only by its breadth. Record heat this summer has battered not just the Northwest, but also the Southwest (where California’s Death Valley reached 130 degrees Fahrenheit, or 54.4 Celsius, possibly the highest temperature ever recorded on Earth). Drought conditions have been reached this year in virtually every western state, including Montana, Idaho, Washington, Oregon, California, Nevada, Arizona, New Mexico, Colorado, and Utah, an expanse of at least 1.1 million square miles. The heat and drought have contributed to record wildfires burning across Oregon, California, and other states. As of Monday, more than 1.6 million acres have burned in California alone, a similar number to the acres burned at this time last year. In 2020, a record 4.2 million acres burned.)
The fires have produced apocalyptic orange skies and emitted harmful particulates to trigger air-quality emergencies. Power systems have teetered under increased demand from the heat and distribution outages caused by the fires (while also, as in previous years, sparking some of the fires). Salmon and other fish species throughout the Pacific Coast states have suffered enormous losses because of declining water levels and rising water temperatures. The juniper tree is facing systemic decline in Arizona and Utah, and because of the extreme aridity, previously burned forests across the West appear to be regenerating more slowly. In mid-August, water levels in Lake Mead, the giant reservoir created by the Hoover Dam, fell so low that the Interior Department declared the first official water shortage in the lake’s 85-year history and announced cuts in the promised water allocations to Arizona, Nevada, and Mexico.
This has been the West’s summer of extremes. In every direction, the consequences of climate change across the region have become more tangible, immediate, inescapable. “It feels like the first inkling of an apocalyptic movie,” Jay Inslee, the Washington governor and a longtime leader on climate issues, told me recently. “People can usually deal with one [threat], maybe two, but this comes to you from every direction.”
Heat, drought, floods, and especially the lengthening and intensifying wildfire season, have compelled the West to reckon with climate change more explicitly than probably any other region in America. But this summer’s convergence of extreme events proves that climate change isn’t a future threat; it’s here. Scientists, political leaders, and environmentalists all broadly recognize that extremes and unpleasant surprises—events that once seemed impossible—will become more commonplace. Even describing climate-related events as unprecedented or unpredictable becomes less meaningful: Is an event that has never happened before really “unpredictable” if such events are now happening virtually every year? Or is it more accurate to say that unpredictable and unprecedented events are now an eminently predictable, even reliable, element of the region’s future? To borrow from the late Donald Rumsfeld’s famous phrase about the Iraq War, the biggest lesson of this year’s severe events may be that the West faces a climate future marked by the certainty of uncertainty, or “known unknowns.” (Even more ominous is that climate scientists don’t rule out the possibility that we’ll experience Rumsfeld’s concept of “unknown unknowns”: threats so novel that we can’t even fully conceptualize them now. Rohde described these as “events that are not just pushing the boundaries a little bit, but are really jumping out at us as something we did not expect based on what we had prepared for in the past.”)
The known changes that have already hit the region are daunting enough. Patrick Gonzalez, a forest ecologist and climate scientist at UC Berkeley who also advises the National Park Service on climate, recently summarized them for me. “Greenhouse-gas pollution from cars, power plants, deforestation … have increased temperature as much as 2 degrees Celsius, 3.6 degrees Fahrenheit, in the Southwest U.S.,” he told me. Combined with a period of lower precipitation (a natural cycle that so far scientists have not definitively linked to the changing climate), that excess heat, he said, has “caused a drought across the Southwest since 2000 that has been the most severe since the 1500s.” Fueled in turn by the heat and drought, forest fires are now annually burning twice as much acreage as the “natural” level recorded through history. In the Mojave Desert alone—which includes Joshua Tree and Death Valley National Parks, as well as the Mojave National Preserve—“increased aridity has caused four out of 10 bird species to disappear locally since the early 1900s,” he said.
To Gonzalez, this pattern of threats is following pretty closely what the climate models warned. But many others I spoke with this summer believe that change is consistently hitting the West at the very high end of what the models considered possible or sometimes beyond it. Mary Nichols, who served as the head of the California Air Resources Board in the 1970s and again from 2007 through last year as the state developed its pathbreaking agenda to reduce carbon emissions, says that although the direction of change isn’t surprising, the pace of it is. “I think the multiple assaults on the system from various directions are absolutely consistent with what the models were predicting,” she told me. “It’s just happening faster than the scientists had been suspecting”—or at least, in their desire to appear cautious, were willing to publicly forecast. Even if scientists had warned of the extreme heat, fire, and drought events the West has experienced this year, “I don’t know [that] they would have been believed,“ she said.
Inslee likewise thinks that he’s dealing with climate effects that push at, or through, the outer boundary of forecasts. “Most days, I am reading something about some scientific data points coming in that are outside the projected range: hotter, drier, faster, whatever,” he said. He expects climate change in the coming years to present the same kind of unanticipated challenges as COVID-19 is doing now—with the coronavirus’s Delta variant powering a massive new outbreak only weeks after the U.S. appeared to be on track to finally contain the pandemic. Like a global pandemic, climate “is a very complex system, and the bad news is it seems like we can’t catch a break: Everything that could go bad in climate is going bad in climate. It’s hard to find a good data point.”
In one sense, experts told me, the convergence of dangerous effects this summer can be seen as coincidental. There will be years that are wetter or drier, hotter or cooler, more prone to fires or less. But, as Rohde said, this year’s simultaneous extremes are “not random,” either. “There are very direct interactions between extremes in heat, extremes in precipitation, and extremes in fire, and so a lot of these extreme events are interacting in such a way that they will tend to pile on top of each other,” he told me. Moreover, as carbon continues to accumulate in the atmosphere, years that simultaneously produce record levels of heat, drought, and fire will become more frequent. “Not every year will be an extreme year; there will be normal years along the way,” Rohde told me, expressing a view echoed by other scientists. “But we will have an increasing frequency of these extreme years, so there will be times when it just stands out like, Oh my God, what is happening?”
To Vijay Limaye, a climate and health scientist at the Natural Resources Defense Council, the most unnerving aspect of the mounting impacts across the West are the feedback loops. “We are seeing really scary signals in recent weeks about the intersecting effects,” he told me. To take one: Long-term, chronic drought means that less of the heat from the sun is consumed to evaporate water from the soil, which “compounds the temperature” rise in the atmosphere. “Then you suddenly expand the possibility of devastating wildfires, and so you have this cascading series of effects.”
Katharine Jacobs, the director of the University of Arizona’s Center for Climate Adaptation Science and Solutions and an expert in water systems, points to the next consequence in the chain. “When it is hotter and it is drier, obviously you have a much higher chance of wildfire, so the watersheds that are upstream from reservoirs may wind up burning,” she told me. “That leads to sediment flows that both reduce the volume of reservoir capacity and increase sediment in the water supply and in some cases actually mean you have to shut down the system. And at the same time, those wildfires are causing air-quality problems that are interfering with virtually everyone who is engaging in outdoor activity.”
These complex dynamics test the ability of any institution to plan for what’s coming. The governments that obtain water from the Colorado River have painstakingly negotiated the supply cutbacks that the federal government announced this month (first affecting Arizona, Nevada, and Mexico, but potentially reaching California before long). Some experts worry that future water flows will be even lower than the official projections, forcing another round of difficult talks for further reductions.
States across the region are also facing the limits of adaptation in confronting fire risk. Local governments are putting more money and effort into maintaining their forests to clear away the dead trees and plants that provide fuel for the wildfires (a cause that former President Donald Trump highlighted as part of his effort to downplay the consequences of climate change). But “you can’t manage your forests out of the problem,” Inslee said. “We are putting hundreds of millions of dollars into managing our forest, but that cannot solve this problem when everything is tinder-dry and one spark means a cataclysm.”
Whether the absolute magnitude of climate change in the West is more severe than in any other U.S. region is an open question: Some of the experts I talked with said yes, while others said that the heat waves and hurricanes in the Southeast or the heat waves and floods in the Midwest may be at least as damaging.
But even so, there’s a general sense among local leaders and scientists that the West remains the U.S. region where life as we know it today will face the greatest disruptions from climate change. The reason is that the West starts with little margin for error. Because it is so arid, development in the West has always been precarious. Since the 19th century, its growth has relied on a sustained triumph over nature, massive engineering projects funded primarily by the federal government to tame its rivers to produce the water and electric power that made possible its growing cities—Las Vegas, Los Angeles, Phoenix (the latter two are the second- and fifth-largest cities in the country). “The modern West is a human construct, dependent on a massive rearrangement of water availability across large areas,” Daniel Farber, of the Center for Law, Energy & the Environment at Berkeley Law, wrote recently. “The physical and legal infrastructure of the West is geared toward a certain climate regime. At great expense and effort, dams, canals, and irrigation systems have been carefully engineered for a climate that no longer exists.”
The experts I spoke with differed on which of the climate-induced changes under way may reshape life in the West the most. Nichols, of the California Air Resources Board, picked the rising atmospheric temperatures. “I think, realistically, it’s the periodic heat waves that just kill people,” she said. “We tend not to pay as much attention to them; we don’t assume there is a right to air-conditioning in most places, but at a certain point, you are going to see large numbers of excess deaths,” along with threats to outdoor work and recreation that will affect “every aspect of how people can live.”
Inslee worries most about the particulates and other air pollutants released in fire seasons that are now both longer and more destructive. “The respiratory issues … are the most, in some sense, immediate because our kids can’t go outside because of the particulate pollution,” he said. “It’s just too unhealthy. We tend to like to breathe, and finding a solution to that is the most challenging. Staying inside right now is the only one, but that is pretty limiting.”
Katharine Jacobs pointed to a problem that isn’t necessarily the most threatening but may prove the most intractable and tragic: the impact of climate change on plants and animals. Although humans can adapt to hotter temperatures by shifting work patterns or adding air conditioners in areas such as the Northwest where they are rare, animal and plant life can’t adapt as quickly or easily. “I am absolutely petrified about the implications for biodiversity and for quality of life, recreation, forest health, all of those things, because you cannot innovate your way into protecting all of that, whereas people have lots of options if they are willing to make adaptive choices,” she said. Mass die-offs of salmon and other freshwater fish in multiple states from rising water temperatures and declining water levels, and the reports of at least 1 billion shellfish (and probably more) boiling in their shells during the Northwest heat wave, underline her point.
But without discounting any of these dangers, most of the experts I spoke with pointed to drought and reduced water supplies as the biggest long-term threat from climate change to the West. Climate change is putting pressure on western water supplies from almost every direction. Because the air is hotter, it draws more moisture from plants; parched soil in turn absorbs more water before allowing runoff to rivers. Snowpack in the mountains, which operates as an essential source of natural storage for the water system, accumulates less (because more precipitation is falling as rain) and then also melts more (because of rising temperatures). One study estimated that each Celsius degree of warming would reduce the water flow in the Colorado River, the principal water source for most of the West, by nearly 10 percent. Even heavier precipitation, the scientists concluded, “will not suffice to fully counter” the robust drying driven by the changing climate. When it comes to water supplies, “every year in the West is a roll of the dice,” Felicia Marcus, the former chair of the California State Water Resources Control Board, told me. “But with climate change, the dice are loaded.”
The squeeze on water supplies from the changing climate isn’t a surprise; scientists have been tracking it for years (which is why states across the region have been compelled to negotiate cutbacks in their allocations from the Colorado River). But, as on many fronts, the shortfalls are developing at the far end of the most pessimistic projections, if not past them. Even people who “have been looking at water-supply issues for several decades and anticipating climate change … have been surprised by how quickly the impacts have escalated,” said Jacobs, who has studied water policy for decades as both an Arizona state official and a senior climate adviser in President Barack Obama’s White House. “The physics of this pretty much were known a long time ago, but as a water manager, I have to say I don’t know of any water managers who understood the dramatic relationship between increase in heat of a few degrees and a reduction in flow of surface water. It goes beyond what seems to be predictable, just thinking about it from a physical perspective.”
The western states, as a group, have actually performed quite well over the past generation in conserving water: Through pricing incentives and mandatory installation of water-saving technologies, California now uses less water than it did in 1980, though its population is far greater. Phoenix and Tucson likewise use no more water than they did in 1985 despite huge population growth, Jacobs said.
Marcus, now a senior fellow at Stanford University’s Water in the West program, said that climate-driven constraints will require further significant tightening. California Governor Gavin Newsom’s request in July that Californians voluntarily reduce their water consumption by 15 percent is likely only the beginning. The good news, Marcus said, is that there are many opportunities for savings. “Urban areas can adapt because we are so wasteful now,” she told me. “We use over 50 percent of our water on outdoor ornamental landscaping, which is mostly keeping a lawn as green as a Scottish golf course … You could get rid of the lawns and plant more trees.” More recycling and recapture of rain runoff (the L.A. area is expanding its water-recycling efforts through two massive projects that are each larger than any now operating in the world, as well as a huge stormwater-capture program funded under a fee measure passed in 2018) can also offset the continuing squeeze on water supplies. Agriculture across the West, Marcus said, will also need to live with “bigger limitations” on its water supplies and learn to grow more with less. On the other side of the water challenge—managing rising sea levels and more dangerous floods—San Francisco has been leading the way with a bond initiative that provides hundreds of millions of dollars to nurture wetlands and tidal marshes that can serve as a natural buffer against floods and capture carbon as well. “We have to integrate the natural world into our thinking,” Marcus said.
Through measures like the Los Angeles and San Francisco Bay Area initiatives, Marcus believes, the West can reconfigure its water system to cope with the reduced supply, even as its population continues to rise. But the pace of change must rapidly increase. And none of it will be painless. Reduced supply to agriculture will affect consumers because California produces such a large share of the country’s fruits and vegetables. (California, for instance, is the source of all of the nation’s commercially grown almonds, a highly water-intensive crop, and less water could mean lower production and higher prices at a time when demand is soaring, partly because almond milk has proved a hit with so many consumers.) And, after restrictions imposed during the last drought expired in 2017, both local and statewide California officials have not shown much appetite for confronting homeowners with limits on water usage for maintaining lawns or hosing down driveways (though the pressure of the new shortfalls could soon change that). Water law will need to adjust as well, Farber said, because the current rules prioritize agriculture and even with conservation, population growth will demand a shift of limited water resources from farms to cities. “We are going to have a lot of political conflict over what to do with an increasingly scarce resource,” he said.
In the end, Marcus believes, adapting to the drier future will be a task comparable in magnitude and difficulty to the original test of building the enormous network of dams and water systems that made the West’s settlement possible in the first place. “It really is going to be the test of our civilization,” she said, “as to whether we can retrofit ourselves to live within our means with the vision and audacity of that original expansion.”
The disruptive climate-change events unfolding now reflect the impact of carbon that was released into the atmosphere years ago. As Nichols noted, the carbon already emitted guarantees that the extreme events happening across the West this year will become more common, and even more severe, “no matter what” we do to reduce emissions going forward. The main question is whether we can slow the rate of emissions to a point that holds those future changes in the climate to a range the West can plausibly adapt to.
The West, as I noted, may be threatened by the changes already baked into the climate more than any other U.S. region, because its aridity means it starts with so little margin for error. It also faces the pressure of growing demands on its natural resources from a steadily rising population: All but one of the 12 counties that added the most people from 2010 through 2020 (including those centered on Phoenix, Seattle, Las Vegas, Houston, and Dallas) are located from Texas to the Pacific Coast.
Should the most environmentally stressed region add people that quickly? Generally, the experts I spoke with said that although adjustment won’t be easy, with sufficient planning and adaptation (things like more water conservation, more air conditioners in the Northwest, more concentrated development to limit expansion into fire-prone areas), the region should be capable of sustaining a continually growing population, albeit not without heavy burdens, such as more punishing heat waves or smoky days that force the residents of big cities to huddle indoors.
But even that conditional optimism rests on a profoundly uncertain foundation. All of the scientists and government officials I spoke with agreed that any hope of adaptation depends on rapidly reducing, and eventually eliminating, the addition of more carbon into the atmosphere. If emissions are not controlled, our adaptations will continually be running behind further deterioration in the climate beyond what planners anticipated. “Ultimately, to have our adaptation responses be manageable, we have to stay committed to very ambitious emission reductions, because if we do not reduce emissions, the effects are going to be that much worse,” says Nuin-Tara Key, the deputy director for climate resilience at the California Governor’s Office of Planning and Research. Gonzalez, of UC Berkeley, likewise said that if emissions are controlled, the West can likely adapt to the changes already locked into the system, but if the world fails to hold the global temperature increase below the international goal of 1.5 to 2 degrees Celsius, the future effects will be extremely difficult to contain—like wildfires at five times the historical average.
On the ground, the future already seems ominously unstable to the activists and officials I spoke with this summer in Sebastopol, a hippie-flavored, now-gentrifying small town in the Russian River Valley northeast of San Francisco. On the western edge of Sonoma County’s wine country, the town is thriving with Bay Area transplants seeking more affordable housing; it’s developed a stylish shopping and eating complex downtown, in a former apple cannery called the Barlow. On the day I was there, families descended with lawn chairs for free afternoon concerts on stages set up in between the craft breweries, wine bars, and boutiques.
In the past few years, the Russian River Valley has experienced almost every danger climate change can offer: flood, drought, wildfires. The fires haven’t yet broken through to downtown Sebastopol, but hardly anyone in the area feels immune after the most intense blaze, in 2017, burned through affluent residential neighborhoods nearby. Then in 2019, severe flooding from the Russian River submerged much of the region, including the Barlow. Fires raged again in 2020. Now drought has left the Russian River (the central attraction for the region’s tourism industry) at a low ebb and forced cutbacks in water supplies. Water shortages have added a new challenge for the area’s many wineries, which already saw nearly one-third of their grapes last year ruined by smoke from the persistent wildfires. (Smoke can leave the grapes tasting, in the evocative if unappetizing analogy many wine growers use, like a wet ashtray.) Kari Svanstrom, Sebastopol’s planning director, told me that she and her counterparts across Sonoma County are all being forced to wrestle with the likelihood that these extreme events will hit more often. “We are looking at increased frequency as well as new impacts that weren’t necessarily planned for in the past,” she said.
Sonoma County, perhaps not surprisingly as an upscale Democratic-leaning place, takes climate change very seriously. The county already generates 97 percent of its power from carbon-free sources, and the county commission earlier this year endorsed the goal of reaching carbon neutrality by 2030—fully two decades ahead of President Joe Biden’s national goal.
Kenna Lee, a home hospice nurse, is participating in all these efforts as the chair of the citizens’ climate advisory committee that Sebastopol’s city council established earlier this year. With its relatively affluent population, she says, the city should become a model for strategies to cut carbon emissions, through ideas such as building community storage facilities for solar energy and constructing renewably powered “resilience centers” that can serve as cooling spaces during heat waves or evacuation points during fires. “This is a wealthy place that should be an incubator for ideas,” she told me when we met in the Barlow. After 20 years living in the area, she’s excited about those possibilities, yet she says that if not for her family situation, she would have moved away already because of the accumulating threats from flood and especially fire. The fires have become so persistent that her company has been forced to develop evacuation plans for all its patients; Lee was worried enough about her own fire risk that she recently moved from her house about two miles outside of town to a new home inside Sebastopol close to the fire department.
Lee is determined to do everything possible to control the risks of a changing climate, through both adaptation and reducing future emissions, but she’s also keenly aware that even if she achieves all the goals she’s working toward, she cannot prevent the risk from increasing. In that way, she personifies the equation facing the West in a warming world. “We tell ourselves” that it is safe to keep living as we have been, Lee told me, “but looking at it from any rational perspective, no one can believe that. We tell ourselves that because, otherwise, we can’t go on living our lives.”
This article previously misstated that 2018 held the record for most acres burned in California. In fact, it was 2020.