California has long been at the forefront of developing rules to reduce automotive pollution levels, but a vote held yesterday could prove to be a landmark for green cars.

The California Air Resources Board (CARB) has been voting on regulations requiring 15 percent of new cars sold in the state by 2025 produce either zero, or close to zero emissions, says Mercury News.

That means a higher proportion of hydrogen fuel cell, battery electric, plug-in hybrid and regular hybrid vehicles on the road by 2025.

As many as 1.4 million of these would be zero-emission vehicles, i.e. hydrogen and battery electric vehicles - up from the 10,000 or so in the state today. That would make them as commonplace by 2020 as regular hybrids are today.

The new regulations would come into force from 2018 to reach the 15 percent target by 2025.

Regular gasoline and diesel vehicles still wouldn't be off the hook, as these would be required to produce 75 percent lower smog-forming emissions, and 50 percent lower greenhouse gases. That will ensure even regular vehicles become significantly cleaner than they are today.

The new rules aren't without their critics. Rep. Darrell Issa (R-CA), who grilled GM CEO Dan Akerson on Wednesday over the Chevy Volt battery fires, has launched an investigation into the new rules. He believes the state is setting national fuel economy standards, a claim denied by Mary Nichols, chief of CARB.

A recent poll by the Public Policy Institute of California found 84 percent of Californians favor tighter gas mileage rules, and several other states are considering copying California's proposed rules.

So could these numbers be achieved? According to Simon Mui, a batteries scientist working with the Natural Resources Defense Council, there's no reason why not.

"We believe it's a pretty reasonable target... Every major automaker and numerous startups are offering some type of plug-in hybrid or pure-electric vehicle already." Even those that don't already have some on the horizon, he explains.

We'll be sure to bring you more news on the voting when we hear it.

Until then, what do you think of the proposed rules? Do you think they're achievable? Let us know in the comments section below.