It's long been obvious that California is the epicenter of emission reduction and electric-car adoption in the United States.

And its outsize influence on U.S. environmental policy has global ramifications as well.

Of the 1.25 million plug-in vehicles estimated to be on global roads by the end of this year, fully one-fifth are in the Golden State.

DON'T MISS: How Many Electric Cars Does California Buy? One-Third To One-Half Of All Of 'Em

That was the news earlier this week from the California Plug-In Electric Vehicle Collaborative, which projects that the state will log the sale of its 250,000th car with a plug this month.

A quarter of a million cars that can run some or all of the time on grid electricity is more than the total of several other states combined.

“Just a few years ago, you could count the number of plug-in models on one hand,” said PEV Collaborative Executive Director Christine Kehoe.

National Plug-In Day 2012: San Francisco, with 60 Nissan Leafs in front of the Golden Gate Bridge

National Plug-In Day 2012: San Francisco, with 60 Nissan Leafs in front of the Golden Gate Bridge

"Times have changed," she continued. “Today, anyone thinking about buying a car can check out more than 30 electric models. And with federal and state rebates, they are more affordable than ever.”

Kehoe's comment underscores a key element in buyer willingness to consider an electric car: a range of different models, types, sizes, and prices.

California's decades-long and aggressive push toward zero-emission vehicles has included a zero-emission vehicle sales mandate since 2012, and the required numbers will start to rise sharply in 2018.

ALSO SEE: Why Electric Cars Are Rare Outside CA: Arcane 'Travel Provision' Rule (Jun 2015)

That means that numerous manufacturers sell at least small numbers of plug-in vehicles in the state that aren't offered elsewhere in the country.

That's largely due to an obscure section of the ZEV rules called the "travel provision," which lets an automaker sell a fully or partially zero-emission vehicle in one state and have it count toward meeting sales requirements in all 10 states that have adopted California's rules.

Light-duty vehicle type scenario, now-2050 (California Air Resources Board)

Light-duty vehicle type scenario, now-2050 (California Air Resources Board)

California is a far bigger market than any of the other states, mostly in the Northeast and Pacific Northwest, that have adopted its rules, making it the easiest way to meet the required sales.

The state also has a far more temperate climate than the Northeastern ZEV states, which are less inherently hospitable to battery-powered vehicles (snow, ewwwwwww!).

The new generation of mass-priced 200-mile electric cars that will start to arrive as the first 2017 Chevrolet Bolt EV is delivered are likely to boost the state's plug-in sales rate sharply.

They will combine the desirability of a Tesla's long range with a sticker price below $40,000 and an effective price that may fall below $30,000, hugely increasing the buyer pool.

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Still, putting a quarter of a million plug-in cars on its roads just 13 years after the state canceled its first set of zero-emission vehicle rules is a win for electric cars no matter what the reasons.

"Californians can take pride in driving the nation toward a zero-emission future,” said Air Resources Board Chair Mary Nichols.

With the possibility that politics may remain contentious at a national level, the state is likely to relish its role in pushing for cleaner cars more than ever.


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