California’s Bay Area is Heating Up. Its Infrastructure Isn’t Designed For It

The region has one of the lowest air-conditioning ownership rates in the nation, but residents are growing increasingly uncomfortable as summer temperatures rise.

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People rest under the shade in San Ramon as a heat wave hits the San Francisco Bay Area in July 2021. Credit: Wu Xiaoling/Xinhua via Getty Images
People rest under the shade in San Ramon as a heat wave hits the San Francisco Bay Area in July 2021. Credit: Wu Xiaoling/Xinhua via Getty Images

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The San Francisco Bay Area is set to endure its first heat wave of the year this month. On June 4, the National Weather Service warned of temperatures touching 100 in the coming weeks. As temperatures across the world rise, each summer is becoming hotter and hotter. Especially in the Bay Area, where summers have historically rarely topped 85 degrees Fahrenheit, the effects of climate change are beginning to appear rather drastically. And contemporary architecture isn’t built for accommodating heat waves and rising temperatures.

California’s Fourth Climate Change Assessment Report for the San Francisco Bay Area Region, released in 2018, found that between 1950 and 2005, the average annual maximum temperature increased by 1.7 degrees Fahrenheit. Additionally, the coastal fog that envelops large parts of the Bay and is responsible for respite from the summer heat is “less frequent than before.” 

The Bay Area’s unique geography gives rise to microclimates in all of the cities surrounding the water. According to Norman Miller, professor emeritus at the University of California, Berkeley’s Geography Department, quantitative data suggests that persistent high pressure over a region heats it up.

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“In California, we have [what’s called] a natural air conditioner in the Bay Area where the sea breeze will set up but if there’s a big high pressure inland then it doesn’t matter. The whole area just gets really hot,” said Miller. These heat and pressure domes have always existed in the Bay Area, but with climate change, the intensity and frequency of these occurrences have increased. 

Founded in the late 1700s, San Francisco was built for cooler climates and older homes in the city aren’t built to accommodate modern cooling systems. 

According to the 2021 American Housing Survey released by the U.S. Census Bureau, San Francisco has the lowest rate of air conditioning ownership in the country, with 34 percent of households having central air and 11 percent having room air-conditioning, while the national average stands at 92 percent. Part of this is because homes in the region weren’t designed to be able to accommodate the eventuality of such cooling systems. 

But the installation and efficiency of air conditioning comes with its own set of problems—they’re not necessarily eco-friendly and the electric grid of the United States isn’t generating enough power to be able to support these cooling systems. 

Drawbacks of Energy-Intensive Cooling Systems

Air conditioners use cooling agents similar to those used in refrigerators—hydrochlorofluorocarbons. These cooling agents can break down into ozone-depleting chemical compounds. Research by Dr. Renee Obringer, assistant professor of energy and mineral engineering at Pennsylvania State University, and her colleagues found that ‘climate induced demand’ for efficient air conditioning in the U.S. would increase by close to 8 percent should the global temperatures increase beyond 1.5 degrees Celsius. This increased demand would have to be met by ramping up energy production which is still heavily fuel-dependent. 

“We’re using more air conditioning because it’s getting hotter out because of climate change and that is in turn using more energy which, in the U.S., is still largely produced through fossil fuels which is worsening climate change and making it warmer, making us use the air conditioning,” said Obringer. “It is this really vicious cycle.” 

The solution is to find alternative energy sources to meet demand. “If we can generate most of our electricity from renewable resources, that will not only help mitigate climate change but it’ll also reduce the impact of responding to ongoing climate change,” she said.

According to Obringer’s research article in the journal Earth’s Future, Americans’ reliance on air conditioning systems coupled with increasing temperatures would eventually make it difficult for the energy grid of the country to distribute enough electricity to support efficient functioning of these A/C systems across the country. The result could be Americans facing prolonged blackouts and as many as 14 days each month without functioning cooling systems. 

“If we can generate most of our electricity from renewable resources, that will not only help mitigate climate change but it’ll also reduce the impact of responding to ongoing climate change.”

Economically weaker sections of the populations, including the elderly and people with pre-existing health conditions, are at a relatively higher risk to bear the brunt of these blackouts and days of extreme heat. 

The lack of access to adequate cooling systems would result in severe public health concerns. According to Associated Press’ analysis of data released by The Centers for Disease Control and Prevention, over 2,000 Americans died in the summer of 2023 due to “effects of extreme heat.” In San Francisco, temperatures above 85 degrees Fahrenheit have triggered increased ER visits, hospitalizations and deaths. 

Real-World Consequences

Data is only one side of the story. People who have spent decades living in the Bay Area can actually feel the change in temperatures. Mary Burns, 62, has lived in San Mateo for almost 40 years. “I don’t remember it getting over 100 degrees. It was never like that before,” she said. “If it got hot in the house, we could open the windows.” 

It isn’t that way anymore. Californians are prone to being impacted by wildfire in one way or another. The Central Valley and many parts of Bay Area counties lie in the fire hazard severity zone as categorized by the California State Fire Marshal. 

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Between 2020 and 2022, Bakersfield topped the list of cities with the highest year-round particle pollution, according to a report by the American Lung Association released earlier this year. Following Bakersfield were five other regions in the state including the San Jose-San Francisco-Oakland area at number five.

The smoke from wildfires spike the EPA’s Air Quality Index into danger zones, adding unbreathable air to the hazards of already hot weather. Burns often has to close windows to escape the smell and pollution from the smoke. 

Burns installed a window-mounted AC in her kitchen six years ago. She spends a lot of time on an office chair there during hot days. “Sitting all day in the kitchen, it’s unpleasant,” said Burns. She isn’t very hopeful it’ll get better, either. 

“I think we’ll have more days of really really hot weather. I don’t know what I base that on but that seems to be what we’ve experienced.”

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