(TNS) — SACRAMENTO, Calif. — Gas- and diesel-powered cars could go the way of dinosaurs if one San Francisco assemblyman gets his way.

Democrat Phil Ting introduced a bill last week that would ban the sale of fossil fuel cars in California after 2040. It doesn’t apply to vehicles over 10,000 pounds.

The ambitious goal has support from environmental groups, but not everyone is convinced the requirement is ready for implementation, even if it wouldn’t go into effect for another two decades. Some question whether the state has enough electric charging and hydrogen fueling stations so everyone can participate in this new, proposed mandate.

But Ting said tackling the problem of pollution coming from passenger vehicles may be the only way to significantly alter the course of climate change. Greenhouse gases emitted from transportation-related activities contributed to nearly 40 percent of all emissions in the state in 2015, according to the California Environmental Protection Agency, the single largest source of pollution.

And, it falls in line with the governor’s goal of bringing the state’s total greenhouse gas emissions to 40 percent below 1990 levels by 2030. He set a goal for California to have 1.5 million zero emissions vehicles on the road by 2025.

“We’re at an inflection point,” Ting said. “By spurring the use of zero emissions vehicles, we’re creating a mechanism to ensure a healthier future for Californians, and the entire region.”

Pollution from car traffic disproportionately impacts low-income communities, the very same people least able to purchase the higher-cost clean-air cars, said Bob Allen, the director of policy and advocacy campaigns at Urban Habitat, a social justice advocacy group. While he supports the transition to clean-air vehicles, Allen said he worries about whether there would be a continued stream of money to support incentive programs to make it more affordable for residents to buy clean-air cars.

“A lot of the time, when (lawmakers) start these transitions, they put money into the initial phase,” Allen said. “I think about the ongoing costs and who will pay for them.”

Even without government incentives, the price of used electric vehicles is dropping as more vehicles enter the market, Ting said.

There just aren’t enough clean air vehicles being made to meet demand, he said, pointing to the long wait list for the newest Tesla Model 3, which hasn’t met production targets and has more than 450,000 eager consumers lining up to buy one. And while zero-emissions vehicles haven’t reached mainstream adoption — just 4.6 percent of all new cars sold in the first three quarters last year in California were clean air vehicles — sales are growing, according to Global Automakers, a trade group that tracks vehicle sales.

But more work is needed to develop the charging infrastructure and hydrogen fueling stations to ensure residents in rural and suburban areas have access to clean air technology, said Eddie Ahn, the executive director of Brightline Defense, an environmental justice organization based in San Francisco. Ahn is a proponent of the bill, but he says the infrastructure is lagging and that can be a problem when it comes to ensuring no one is left behind when California makes the switch to clean-air cars.

Those details can be worked out over the next 20 years, but it’s important to set an ambitious long-term goal, said David Reichmuth, an engineer with the Union of Concerned Scientists. Since 2010, when Nissan introduced its plug-in Leaf and Chevy introduced the Volt, there’s been rapid growth in the number of new models, he said. And, he expects that trend to continue, with or without government intervention.

“This is the direction the car companies know they have to go,” he said.

No one has a crystal ball, Reichmuth said, especially not for the auto industry which is already undergoing a serious identity crisis with the advent of autonomous cars. Will there be human drivers in 2040? Will people even own their own cars? The answers to those questions are not as important as how those cars will be fueled, he said.

“I don’t think we need to know exactly what the vehicles will look like or what the infrastructure looks like in 20 years,” Reichmuth said. “But we know what it will need to look like, and it will need to get rid of combustion engines and replace dirtier fuels with clean ones.”

©2018 the Contra Costa Times (Walnut Creek, Calif.) Distributed by Tribune Content Agency, LLC.