Two of the Bay Area’s largest cities — San Jose and Oakland —  this week banned natural gas from nearly all new construction, pushing all-electric infrastructure as their latest tool to fight climate change.

In doing so, San Jose made history by becoming the largest U.S. city so far to take that leap, although more than three dozen smaller cities across the nation had already done so. Berkeley became the first city in the country to prohibit natural gas when it passed an ordinance in the summer of 2019, and San Francisco recently followed suit.

“I am confident that we are taking a huge step here that is going to get us much, much closer to our climate goals,” San Jose Mayor Sam Liccardo said Tuesday when the City Council voted  8-3 to prohibit natural gas in new commercial and high-rise residential buildings beginning in August 2021. Council members Raul Peralez, Magdalena Carrasco and Pam Foley dissented, siding with environmental advocates who opposed an exemption added at the eleventh hour.

“State energy policies and lower prices of renewables mean that substituting natural gas with electricity is one of the quickest, safest and least expensive pathways to eliminating greenhouse gas emissions from buildings,” said Oakland Councilmember Dan Kalb, lead author of that city’s ordinance prohibiting natural gas in newly constructed apartment and commercial buildings. The Oakland City Council unanimously approved the ordinance.

“Reducing the reliance on gas systems will reduce the risk of fires, simplify building systems and maintenance, and improve indoor air quality,” added Kalb, who introduced the ordinance along with Oakland Mayor Libby Schaaf and Councilmember Nikki Fortunato Bas.

Although natural gas has been heavily marketed as more environmentally friendly than other fossil fuels such as coal, the energy source has been found to be much more damaging to the climate than electricity.

San Jose’s move expanded upon a city ordinance that went into effect in January barring natural gas in new single-family homes, detached granny flats and low-rise multifamily buildings up to three stories.

The ban does not apply to existing homes or commercial buildings. Hospitals and new dwelling units attached to an existing home also will be exempt, and food-service establishments and manufacturing facilities facing financial difficulties can apply for “limited hardship exemptions” through the end of 2022.

The particular exemption that drew backlash from dozens of San Jose residents, students and environmental advocates dealt with facilities that wish to generate and store energy on-site. Under the expanded ordinance, those facilities would not have to solely rely on electric energy until at least Dec. 31, 2024.

The exemption was added just one day before the council was expected to take up the proposed ban earlier this month, forcing a delay on the vote for two weeks. It was prompted by alarms raised at the last minute by Bloom Energy, a publicly-traded fuel cell company based in San Jose that sued the city of Santa Clara earlier this year over a requirement to meet certain climate standards. Mayor Liccardo’s friend and former Silicon Valley Leadership Group CEO Carl Guardino now serves as executive vice president of the company.

Bloom’s fuel cells, which run continuously, are not vulnerable to electric power outages and can therefore provide a critical energy source during PG&E’s power safety shutoffs that left hundreds of thousands of Bay Area residents without power this fall. In a letter to the city, Guardino argued that intermittent renewable resources must be paired with reliable generation such as the Bloom boxes to “keep the lights on and business running.”

The issue for environmentalists, though, is that the fuel cells generate electricity using mainly natural gas, run at all hours of the day — not just during power outages — and emit more than three times as much carbon dioxide as power from the city’s utility, San Jose Clean Energy, according to city and Bloom figures.

Olivia Walker of the Natural Resources Defense Council called the exemption for companies like Bloom an “unnecessary and counterproductive” loophole that would allow “unfettered use of fuel cells powered by fracked gas.”

Still, the majority of council members sided with Liccardo, who argued that guaranteeing companies have an uninterrupted supply of energy despite the region’s unreliable power grid was essential.

“We’re pushing folks toward an electric grid that is not reliable and not dependable,” the mayor said. “We hope all that changes in the years ahead, but PG&E is many years and tens of billions of dollars away from fixing its problems.”

In Oakland, proponents of the ordinance said it’s also about equity: The pollutants created by natural gas are compounded in small, badly ventilated spaces, such as old apartments. A city staff report cited research noting that children living in homes with gas cooking are 42% more likely to have asthma than those without.

While gas rates are now lower than electricity rates, they are increasing at a faster clip overall, the city report notes, adding that as more buildings become electrified, gas infrastructure costs — and thus the rates for consumers — will continue to rise.

When Berkeley approved its then-historic ordinance, the California Restaurant Association pushed back by suing the city in an effort to stop the ban, noting in the complaint that “restaurants rely on natural gas for such things as food preparation and heating space and water, and even providing backup power during electrical outages. Many of these restaurants rely on gas for cooking particular types of food, whether it be flame-seared  meats, charred vegetables or the use of intense heat from a flame under a wok.”

The lawsuit is ongoing. Environmental groups have urged the restaurant association to stand down, and proponents of banning natural gas point to the surge of chefs who have turned to induction cooking over either gas or electric ranges.

Oakland’s ordinance will be effective immediately upon its second reading in mid-December.