The internal combustion engine’s periods may be numbered in California, where officials are mulling whether a ban on sales of polluting autos is needed to achieve long-term targets for cleaner air.

Governor Jerry Brown has expressed an interest in barring the sale of vehicles powered by internal-combustion engines, Mary Nichols, chairman of the California Air Resources Board, said in an interview Friday at Bloomberg headquarters in New York. The earliest such a banning is at least a decade away, she said.

Brown, one of the most outspoken elected official in the U.S. about the necessity of achieving policies to combat climate change, “wouldve been” replicating similar moves by China, France and the U.K .

” I’ve gotten messages from the governor asking,’ Why haven’t we done something already ?'” Nichols said, referring to China’s planned phase-out of fossil-fuel vehicle marketings.” The governor has certainly indicated those who are interested in why China can do this and not California .”

Embracing such a policy would send shockwaves through the world car industry due to the heft of California’s auto market. More than 2 million new passenger vehicles were registered in the state last year, topping France, Italy or Spain. If a prohibit were implemented, automakers from General Motor Co . to Toyota Motor Corp. would be under new pressure to construct electric vehicles the standard for personal transportation in the most populous U.S. country, casting fresh uncertainties on the future of gasoline- and diesel-powered autos elsewhere.

The Association of Global Automakers said consumers must be able to afford the cleaner cars that California says are needed to meet its climate objectives. The trade association represents Toyota, Honda Motor Co. and other overseas carmakers in the U.S.

“We have been working with California on intelligent, market-based approaches to emissions reductions beyond 2025, and we hope that this doesn’t signal an abandonment of that position, ” Global Automakers Chief Executive Officer John Bozzella said in a statement.

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California has specified a aim to cut carbon dioxide emissions by 80 percent from 1990 levels by 2050. Rising emissions from on-road transportation has undercut the state’s efforts to reduce pollution, according to Next 10, San Francisco-based non-profit.

” To reach the ambitious high levels of reduction in greenhouse gas emissions, we have to pretty much replace all combustion with some sort of renewable energy by 2040 or 2050, ” Nichols said.” We’re looking at that as a method of moving such discussions forward .”

Legal Means

California has the authority to write its own pollution rules, which dates back to the 1970 Clean Air Act. Those regulations are underpinned by waivers granted by the Environmental Protection Agency.

Nichols said the state is very likely to take a different legal route to enable a possible forbidding rather than use an EPA waiver, since the Trump administration would be unlikely to approve one. For instance, California could use vehicle registration rules or control the vehicles that can access state highways, she said.

” We certainly wouldn’t expect to get a waiver for that from EPA ,” Nichols said.” I think we would be looking at use some of our other authorities to get to that ensue .”

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China will likely order an purpose to sales of all polluting vehicles by 2030, the chairman of electric-carmaker BYD Co. said Thursday. France and the U.K. have announced 2040 as their aim date for sales of fossil fuel-powered cars.

A ban for California could also still be decades away from implementation, and just how far out remains to be seen, Nichols said.

” There are people who belief, including who work for me, that you could stop all sale of new internal-combustion cars by 2030. Some people say 2035, some people say 2040 ,” she said.” It’s awfully hard to predict any of that with precision, but it doesn’t appear to be out of the question .”