California is officially saying goodbye to gasoline-powered vehicles, phasing them out by 2035 in a move to reduce greenhouse gas emissions. Although sales of new vehicles will be banned, the government will still allow vehicles to be owned and sold on the used-car market.

Governor Gavin Newsom enforced the plan through an executive order. It’s the most aggressive clean-car policy in the United States so far. Newson also supported a ban on petroleum fracking but he will let the California Legislature decide on that instead of signing another executive order.

“This is the most impactful step our state can take to fight climate change,” the governor said in a statement. “Our cars shouldn’t make wildfires worse — and create more days filled with smoky air. Cars shouldn’t melt glaciers or raise sea levels threatening our cherished beaches and coastlines.”

California has been severely hit by wildfires and heatwaves, with Newson claiming the fight against climate change has to be accelerated. Nevertheless, the state’s efforts have clashed with the Trump administration, which has sought to revoke California’s authority to enforce a shift towards zero-emission vehicles. The issue is now in court.

While the state has successfully tackled several sources of emissions, transportation remains its biggest (and growing) problem. Former Governor Jerry Brown signed an executive order in 2018 to have 200 hydrogen fueling stations and 250,000 electric vehicle chargers installed by 2025 to support the growing numbers of clean vehicles.

The number of zero-emission electric vehicles being sold in the state has been growing in recent years. Nevertheless, they accounted for fewer than 8% of all new cars sold in California last year. By 2035, Bloomberg projects, about half of US passenger vehicle sales will be battery and plug-in hybrid electric vehicles.

“The Governor’s Executive Order is a meaningful step in addressing the climate crisis and protecting the health of Californians,” the California-based Coalition for Clean Air said in an email to NPR. “Electrifying transportation will also create jobs and help California move forward in its economic recovery.”

Newsom’s order, which he signed on the hood of the forthcoming electric Ford Mustang Mach-E, will probably set the tone for the whole country. California is the largest car market in the US and also one of the biggest gasoline consumers. Still, questions remain, including whether the state will allow the sale of plug-in hybrid cars.

Whether other states join or not will likely depend on the upcoming presidential election. While the Trump administration has challenged California’s efforts to reduce transportation emissions, Democratic presidential nominee Joe Biden has advocated for the widespread adoption of electric cars and the construction of a national charging network.