San Francisco Chronicle - (Sunday)
Fastest-growing areas of state to be hottest
Many moving to interior from cooler coast regions are Black, Latino, Asian
In the 1990s, Justin Johnson was one of two Black kids at his school in Roseville, a suburban community in Placer County northeast of Sacramento. The other one, he says, was his brother, Joel.
Fast-forward decades, and that’s changed dramatically, Johnson said. Now, when he drops off his high school senior daughter at school, he sees dozens more Black kids. “Is it what you would consider diverse? Probably not in comparison to the Bay Area. But compared to what it was, it’s a night-and-day difference.”
Placer County is among the places in California where Black, Latino and Asian populations have grown significantly from 2010 to 2020 — and it’s also one of the places in the state that’s expected to get the hottest with global warming.
Many of the fastest-growing communities in California are in areas expected to face the highest temperature increases by the end of the century, The Chronicle’s analysis of temperature projection and population data shows. Much of the population growth for new residents in the
region was fueled by exorbitant housing costs in coastal metro areas driving migration within the state to suburban and rural areas.
Across California, average summer temperatures have already risen by approximately 3 degrees Fahrenheit since 1896, the cascading impacts of which have already begun playing out — extreme heat events, rising sea levels, heightened wildfire risk and more severe drought, just to name a few. Temperatures will continue to rise barring drastic reductions in greenhouse gas emissions, ac
cording to projections by Cal-Adapt, a multiagency effort to parse and share important climate change data.
By the end of this century, projections under a high-emissions scenario, temperatures in California would rise by an average of almost 9 degrees Fahrenheit. Inland areas are projected to have greater increases than areas along the coast, with temperature jumps varying from 6 to 11 degrees in different parts of the state.
The difference between a few degrees may not seem like a lot, but what you can't see in the averaged data are individual extreme heat events, which can be deadly, explained Owen Doherty, the climate science lead for CalAdapt. There will also be strains to the state's energy grid and water supply, as well as increased risk of wildfires and floods.
“It (will) really change your environment and the way you live in ways that we may not fully anticipate yet,” he said.
Meanwhile, California's population continued to grow and shift, with much of the new housing construction in the state happening in areas at “significant risk of the effects of climate change,” including in the Central Valley and Inland Empire regions, according to a California Legislative Analyst's Office report published in April 2022.
The number of residents identifying as white declined across the state from 2010 to 2020, but the white population declined least in the coolest-projected parts of the state. In contrast, the number of Black residents declined in cooler areas while growing in hotter ones. The number of Hispanic and Asian residents grew across the board, but with the Hispanic population growing the fastest in the areas projected to see the largest temperature growth.
“As we keep developing these regions, we're increasing our exposure at a time where the risk is growing very quickly,” Doherty said. “And that combination, unfortunately, as we've seen, can turn out to be lethal.”
And it's unclear if these growing communities with hotter futures are prepared for what's to come, he said. Some of them may not have sustainable water supplies that can withstand droughts or the energy capacity to shield people from heat during the hottest times.
Many factors play into where housing is built and why people move, the climate scientist said. “Climate has historically not been the top one. They're looking to move where the jobs are and where houses are affordable, particularly in California.”
There are trade-offs to moving somewhere with more affordable housing but a grimmer climate outlook, said Colleen Callahan, co-executive director of the UCLA Luskin Center for Innovation, which works on solving environmental challenges through actionable research.
“Maybe someone might have lower rent if they move to Bakersfield, but they will probably have higher electrical costs. Is that really being factored into their financial planning? Is the state or their utility prepared for the influx of people needing more assistance?”
The state's Legislative Analyst's Office also found that the adverse impacts of climate change will be felt disproportionately among those who live in parts of the state exposed to higher risks, including low-income residents.
Rising temperatures will only exacerbate existing inequalities, Callahan said. “Climate change will only continue to deepen (inequality) unless we take targeted action, and the state is starting to do so, but it has a lot further to go,” she said.
Adapting to a new future
The population of Placer County, where Justin Johnson, the Realtor, lives, grew by about 16% from 2010 to 2020. Much of that growth was driven by an increase of Asian, Hispanic and Black residents. The Cal-Adapt projections suggest this area's average temperature will increase by more than 9 degrees Fahrenheit at the end of the century.
In his experience as a Realtor in the area, the main driver in Placer's growth is the relatively low cost of living. “Compared to the Bay Area, obviously there is a dramatic difference. People can sell their homes there, come up here and buy what they would consider a dream home.”
A typical home in Roseville, the largest city in Placer County, costs about $668,000, compared with $1.5 million in San Francisco, according to data from the real estate company Zillow.
Placer County's proximity to wilderness areas is also a major draw — it straddles the Sacramento Valley and Sierra Nevada. But that comes at a price; proximity to wilderness also means higher risk of exposure to wildfires, which is further exacerbated by the impacts of rising temperatures.
Nearly half the county is in what fire officials and scientists call “wildland urban interface” — an area where structures and other human development meet wilderness, according to the U.S. Fire Administration. Multiple fires have burned already in Placer County this year, including the Mosquito Fire, which destroyed 78 structures and forced more than 11,000 people to evacuate.
Roseville was spared from the Mosquito Fire's blazes, save for the impacts from smoke, but wildfires and other climate-related matters are still on many new potential home buyers' minds.
Summers in Placer County, particularly closer to the more urban western portion of it, can experience brutal heat. But because it already gets pretty hot, homes — even older ones — generally have air conditioning, Johnson said. “You can't live without it.”
The Central Valley, the region in California's midriff where much of the farming takes place, is another growing region where the impacts of rising heat concern many scientists. The region is already coping with many environmental challenges, including overdrafted groundwater basins that worsen with heat and drought.
Across the vast Central Valley and its 13 counties, the populations of all but one county (Kings) increased from 2010 to 2020, with San Joaquin County growing the fastest, at about a 14% increase compared with the statewide average of about 6%.
But like Placer County, the Central Valley is no stranger to heat, and many homes already have air conditioning. So in that sense, the region, and especially its bigger cities like Fresno, may be better prepared for rising temperatures, experts say.
But not everyone will be spared. “Those that will be impacted most include those least able to adapt,” Callahan of UCLA's Luskin Center said. That includes people without air conditioning, those with energy-inefficient homes or residents of mobile homes, and those who have air conditioning but can't afford to turn it on.
The Central Valley is home to many farmworkers who work outside in the fields, sometimes during the hottest times of the year, and without shade. The vast majority of such workers in the state are Latino.
Often, those who need cooling the most or shade to shield them from the sun are the people who tend to have the least of those things, said Ruth Engel, an environmental data scientist at the Luskin Center, where researchers have developed a mapping tool to gauge who would be the most impacted by rising temperatures.
“Inequity is worst in areas where populations are vulnerable and they are unable to access resources, and the governance systems have been unable to provide them with resources that can help them adapt to climate change and worsening heat,” she said.
What the future may hold
Back in 1988 when Johnson's family was moving from San Francisco to Roseville in Placer County, he doesn't recall heat or fires being much of a concern for his family. The oldest memory he has of fire risk in his community dates back to when he was in high school, when students had to practice football indoors because of fire smoke.
“It was not like it is now,” the Realtor and father said. Still, he says he also feels his community in Roseville is well prepared, with homes equipped with air conditioning and much of the community well aware of fire risks.
Even then, to hear that temperatures could rise by more than 9 degrees is “shocking,” he said. “That is kind of scary when you start thinking about the magnitude of the impact,” he added,
But it doesn't have to be this way, experts say.
The obvious and best way to reduce the risk for people living in places most likely to be adversely impacted by climate change and rising temperatures is to “get our butts in gear” and escape the worst-case-scenario trajectory, Doherty of Cal-Adapt said. That would require significantly reducing greenhouse gas emissions to minimize the warming.
Under a scenario where global emissions actually decline after 2040, temperatures across the state would increase by an average of about 6 degrees Fahrenheit at the end of the century, compared with nearly 9 degrees under the high-emissions scenario, which is more reflective of “business as usual,” Doherty said.
Reducing emissions is easier said than done, he and others say, as people disagree on how exactly to achieve such a daunting task.
It also inevitably involves reducing energy use, which is required to keep people cool in already hot places. “There's going to be a tension between wanting to reduce climate pollution and wanting to save lives,” Callahan said. “At a certain point, we can't deny people access to lifesaving air conditioning and be moral.”
Meanwhile, the coastal metro areas projected to stay cooler, such as San Francisco, continue to battle housing shortages and homelessness.
There's no one magic solution to addressing global warming and its impact on heat, the experts say. But there are many things that people, communities and the government can immediately take action on to make a difference, Engel, the Luskin Center data scientist, said. They include creating more shaded areas and establishing laws to protect the most vulnerable, including renters, from heat.
Many people are simply not going to move elsewhere from where they have ties to get relief from heat, Engel said. “They can't lose their lives around heat relief, so bringing relief to them and bringing shade to them is really where we can make a difference,” she added.