This Yahoo News series analyzes different regions around the country in terms of climate change risks that they face now and will experience in the years to come.
As the negative consequences of rising global temperatures due to humankind's relentless burning of fossil fuels become more and more apparent in communities across the United States, anxiety over finding a place to live safe from the ravages of climate change has also been on the rise.
"Millions and likely tens of millions of Americans" will move because of climate through the end of the century, Jesse Keenan, an associate professor of real estate at the Tulane University School of Architecture, told Yahoo News. "People move because of school districts, affordability, job opportunities. There are a lot of drivers and I think it's probably best to think about this as 'climate is now one of those drivers.'"
In late October, a report by the United Nations concluded that average global temperatures are on track to warm by 2.1° to 2.9° Celsius by the year 2100. As a result, the world can expect a dramatic rise in chaotic, extreme weather events. In fact, that increase is already happening. In the 1980s, the U.S. was hit with a weather disaster totaling $1 billion in damages once every four months, on average. Thanks to steadily rising temperatures, they now occur every three weeks, according to a draft report of the latest National Climate Assessment, and they aren't limited to any particular geographical region.
To be sure, calculating climate risk depends on a dizzying number of factors, including luck, latitude, elevation, the upkeep of infrastructure, long-term climate patterns, the predictable behavior of the jet stream and how warming ocean waters will affect the frequency of El Nino/La Nina cycles.
“No place is immune from climate change impacts, certainly in the continental United States, and throughout the U.S. those impacts will be quite severe,” Keenan said. “They will be more severe in some places and less severe in other places. Certain places will be more moderate in terms of temperature and some places will be more extreme, but we all share the risk of the increase of extreme events.”
In this installment, we look at a region that is fast being overtaken by scorching temperatures, worsening drought and an increased threat from wildfires.
If there’s one thing that unites the expansive Southwest region of the United States, which includes California, Nevada, Utah, Colorado, New Mexico and Arizona, it is the area’s relative scarcity of fresh water.
This year, amid an ongoing megadrought across the Southwest, the Department of the Interior announced water rationing measures to states that rely on supplies from the dwindling Colorado River. Approximately 40 million people get water from the Colorado's river system, and rising temperatures are one factor reshaping the water cycle in the region.
"The average flow of the Colorado River has already declined nearly 20% since 2000, with half of that attributable to rising temperatures," the Nature Conservancy states in an article on its website. "Temperatures in the Basin are predicted to rise another 2-5 degrees Fahrenheit by 2050, which could reduce river flows by another 10 to 40%."
While climate change is not the sole driver of drought, scientists have shown that it makes them dramatically worse.
“We know that in the Southwest, with the ongoing megadrought, 40-50% of its severity can be attributed to warming temperatures alone,” UCLA climate scientist Daniel Swain told Yahoo News.
Rising temperatures throughout the Southwest, which the Environmental Protection Agency ranks as the "hottest and driest region in the nation," have not only stressed water resources there, the resulting increase in evaporation rates are drying out vegetation and increasing the risk of wildfires.
A U.S. Forest Service report released this spring concluded that its employees underestimated the impact of climate change on the ecosystem in the Southwest when it attempted a controlled burn to diminish the threat of wildfires in New Mexico. That miscalculation helped cause the Hermits Peak/Calf Canyon Fire, the largest conflagration in the state in recorded history, which devoured 341,471 acres and at least 903 structures.
In part as a result of that wildfire, and due to the overall effect climate change is having on states like New Mexico, some homeowners have faced a rude awakening when it comes to insuring their properties.
"I'm very concerned that moving forward these natural disasters are either going to raise premiums or we're going to be in a deeper crisis like Florida, where insurance providers don't want to come to New Mexico because it's a very challenging market to insure," New Mexico Attorney General Hector Balderas told The Associated Press.
While climate change has been shown to worsen natural disasters, it is also ushering in a brutal new normal for places like Phoenix, Ariz., where the average summertime temperature has risen by 3.8 degrees Fahrenheit since 1970. Climate models predict that average will rise by an additional 10 degrees by the year 2100, bringing daily average summer readings of 114 degrees F. And yet, despite the specter of routine water shortages and regular oven-hot summer heat, Phoenix grew faster than any other big American city between 2010 and 2020, according to Census Bureau data, adding 163,000 residents.
Prolonged exposure to such high temperatures is, of course, dangerous to human health, and Southwestern cities have had no choice but to acknowledge that fact, creating new government positions to try to cope with the emerging reality. This year, Los Angeles hired a “chief heat officer,” to come up with a plan to reduce heat-related hospitalizations and deaths. In 2021, Phoenix used taxpayer funds to establish an Office of Heat Response and Mitigation to do the same, but it remains to be seen whether planting more trees, revamping building codes and coating roadways so that they reflect rather than absorb heat will achieve that goal.
If greenhouse gas emissions continue on their current path, the Southwest can expect "the highest increase in annual premature deaths due to extreme heat in the country," according to the Centers for Disease Control and Prevention, "with an estimated 850 additional deaths per year by 2050." Given the rising problem of homelessness across the region, that estimate may prove woefully conservative.
Since 2014, deaths attributed to heat in Maricopa County, Ariz. — which includes Phoenix and nearby cities like Mesa, Scottsdale and Tempe — have spiked by 454%, KPNX News reported. For the past two years, the county has set new heat death records, with 323 people killed in 2020 and 331 in 2021, the bulk of those occurring in Phoenix.
Like every other region in the U.S., there are better and worse places to settle in the Southwest when it comes to climate change risks. The truth is, however, that weighing those factors can ultimately boil down to a matter of personal preference rather than a guarantee.
"What are you most afraid of? What are you trying to mitigate the most? I don't think I'd live in a heavily wooded canyon anywhere in the American West for wildfire reasons," Swain, who consults for ClimateCheck, a company that provides climate change risk assessments on real estate nationwide, told Yahoo News. "I don't think I'd literally be able to sleep at night because the risks have gotten so high in a lot of these places."
According to a 2020 analysis published by ProPublica and the New York Times of findings provided by the Rhodium Group, a data-analytics firm, all of the Southwest's top 10 safest-rated counties from climate change risks are located in Colorado — Summit, Grand, San Juan, Park, Lake, Hinsdale, Gilpin, Clear Creek, Rio Grande and Ouray.
The analysis considered six major categories — heat stress, the combination of heat and humidity (wet bulb), crop loss, sea level rise, very large fires, and overall economic damages — and rated each county on the impact climate change would have on them given two emissions scenarios: high and moderate. The biggest vulnerability for the top-rated Colorado counties was from fires, but each scored low on most other measures.
Owing to a combination of poor scores on categories such as heat stress, wet bulb, crop loss and very large fires, 6 of the 10 Southwestern countries that ranked worst are found in Arizona — Pinal, Graham, Cochise, Mohave, Maricopa and Yuma. California, meanwhile, accounted for 4 of the Southwest’s bottom 10 counties — Fresno, Tehama, Shasta, and Imperial.
Across the Southwest, insurance companies have begun reevaluating whether to offer coverage to homes located in areas with elevated wildfire risk, but the dangers extend beyond the structures and lives inside of burn zones. In 2021 and 2022, after consecutive years of dealing with heavy wildfire smoke for weeks on end in heavily populated California cities like Oakland, San Francisco, San Jose and Sacramento, several new scientific studies were released documenting the adverse health effects caused by exposure to smoke from wildfires.
"During the 2020 California wildfire season, my team conducted a study on healthy individuals and found alarmingly increased numbers of abnormal, activated immune cells in the peripheral blood. These cells are normally responsible for protecting against inflammation and infections, but when altered by inhalation of wildfire smoke, they become the ones promoting inflammation," Dr. Angela Haczku, director of the UC Davis Lung Center, told Pulmonology Advisor.
While the biggest dangers from wildfire smoke are for people who are closest to it, as wildfires have grown in size and frequency thanks to climate change, dangerous smoke from them has become increasingly common in other states.
Staying on top of the evolving risks is itself a full-time job, introducing residents to websites that rate air quality. But perhaps the most daunting thing about climate change is the number of threats it promises to unleash.
Earlier this year, Swain co-authored another study that found that rising temperatures have essentially doubled the risk in California of a catastrophic megaflood that could transform low-lying areas in the state into a "vast inland sea" and rack up a trillion dollars in losses.
“I guarantee you that most people in California are not thinking that one of the biggest risks of a warming climate is the risk of extreme flooding. But that is one of the things that I would highlight as the largest risks in California,” Swain said.
Experts on how climate change is altering the water cycle stress that over the coming decades regions like the Southwest can expect a chaotic future in which one extreme replaces another.
"The climate is changing. What used to be normal is no longer normal, and we're not approaching a new, stable normal — a 'new normal.'" Climate scientist Peter Gleick told the Santa Barbara Independent. "Rather we're entering a period of rapid, unstable changes, and we're not adequately prepared."
Even in areas that do well on rankings of overall climate change risks, there are no real assurances. Following an especially dry autumn and nearly snowless winter, the Marshall Fire of 2021 erupted in Boulder County, Colo. A grass fire fed by wind gusts measuring 115 miles per hour, it advanced at a frightening rate of a football field per second, the same pace witnessed during the 2018 Camp Fire in California. Over the course of a single day, it became the most destructive wildfire in the state's recorded history, destroying more than 1,000 homes and totaling more than $1 billion in insurance losses.
"It's personal. It's front and center [in Colorado]," Devon Herndon, a therapist who treats patients for climate anxiety in the tiny mountain town of Cotopaxi, two and a half hours south of Denver, told Yahoo News in January. "Our forests are dead and dying rapidly. It's no longer getting cold enough to kill the parasitic bugs in our pine trees. Then we have a whole bunch of standing dead [trees] that are giving fuel to the wildfires."
As the Southwest shows, as temperatures continue to rise, so do the number and scope of climate change risk factors, leaving communities unprepared to adapt for what’s coming.
“I suspect that’s true in a lot of places where we’re actually missing some of the biggest risks,” Swain said. “So how good are these assessments if they haven’t been pretty circumspect, even creative, about what dragons might be out there?”
Even known risk factors present local officials with difficult choices. The city of San Francisco, for instance, commissioned a report last month with the U.S. Army Corps of Engineers to try to figure out how to protect the city from sea level rise.
If greenhouse gas emissions continue at their current levels, global temperatures continue to rise and the melt of the polar ice caps continues apace, the city could see 7 feet of sea level rise by 2100, according to a 2022 report by the California Ocean Protection Council. While 78 years may seem like enough time to figure out a solution, due in part to the 8 inches of sea level rise San Francisco has recorded since the start of the Industrial Revolution, many neighborhoods are already prone to flooding during king tides.
The report on how to try to save those homes and businesses won’t be finished until next October.