Governors from eight states pledged to put 3.3 million zero-emission cars on the nation's roads by 2025.

The eight states -- California, Connecticut, Maryland, Massachusetts, New York, Oregon, Rhode Island and Vermont -- represent nearly one quarter of the country's auto market.

Under an agreement announced Thursday in Sacramento, initiatives to pursue the goal include installing more electric charging stations, introducing or extending tax breaks for consumers and adding zero-emission vehicles to government fleets.

Zero-emission vehicles include battery-electric vehicles, plug-in hybrid-electric vehicles, and hydrogen fuel-cell-electric vehicles.

Electric car sales in the nation more than tripled last year to about 52,000, from 17,000 in 2011, figures from the coalition show.

In the first and second quarters of this year, 40,000 plug-in cars were sold.

"We think it's doable," Mary Nichols, chairman of the Air Resources Board in California, the biggest market in the group, was quoted as saying by The Washington Post. "The market is moving fast."

A Massachusetts Institute of Technology study released in August found air pollution accounted for 200,000 premature deaths in the United States in 2005, more than 58,000 of which can be attributed to vehicle emissions.

"This agreement is a major step forward to reducing the emissions that are causing our climate to change and unleashing the extreme weather that we are experiencing with increased frequency," said New York Gov. Andrew Cuomo, in a statement.

"This collaboration builds on New York's Charge NY initiative, which is creating a statewide network of 3,000 charging stations by 2018 and will provide New Yorkers with a convenient and affordable alternative to increasingly expensive gasoline and diesel," Cuomo said.

The Union of Concerned Scientists applauded the eight-state agreement, calling it "a key solution for tackling climate change and cutting our nation's projected oil use in half over the next 20 years."

"Reducing barriers to electric vehicle adoption through incentives and support for refueling infrastructure will provide more choices for consumers, lower fuel costs, and reduce pollution," said David Reichmuth, senior engineer with the union's Clean Vehicles program, in a statement.

Analysts at the Kelley Blue Book auto information service questioned the practicality of the group's goals.

"As it stands today, zero-emission vehicles remain out of reach for the typical budget-conscious consumer, especially when compared to far more affordable compact and subcompact cars," Alec Gutierrez, a senior analyst at Kelley, was quoted as saying by the San Jose (Calif.) Mercury News. "Until battery costs come down, electric-vehicle range increases, and infrastructure to support zero-emission vehicles improves, we expect to see market share continue to grow at a snail's pace in the short term."