Automakers, who earlier this week filed a lawsuit to block new California emissions standards, are right that the federal government should set such standards. As the automakers contend, a national standard is preferable to differing sets of state regulation. But, in the absence of federal action on reducing pollutants that contribute to local health problems and global climate change, states such as Maine are right to step in.

In September the California Air Resources Board approved rules requiring a 30 percent reduction in emissions of the heat-trapping gases from passenger cars between 2009 and 2016. The state represents about 10 percent of the U.S. car market. Many states follow California’s lead on auto emissions rules. Combined, these states comprise about a quarter of the car market.

Last week, the Maine Board of Environmental Protection approved adoption of California’s zero-emissions standards. The change must still be approved by the Legislature. The state had delayed joining the rest of New England, except New Hampshire, in adopting the rule because only electric cars, which are not practical in Maine’s climate, met the original standard.

California has since changed its requirements to allow hybrids and clean-burning gasoline cars to qualify so long as 250 fuel cell vehicles are on the road nationwide by 2008. Now that gasoline-hybrid cars with the latest emissions technology qualify, the BEP voted to move ahead with adoption of the California rule requiring that 10 percent of new vehicles sold in Maine in 2009 meet zero emissions standards. Of these, 6 percent can be conventional fuel vehicles and 4 percent must be hybrids.

According to the Department of Environmental Protection, many of the most popular compact cars and small sedans already sold in Maine already meet the clean gasoline standard. Among them are some models of the Ford Focus, Subaru Legacy, Toyota Camry, Nissan Sentra, Dodge Stratus and Honda Accord.

Emissions of carbon dioxide, the most prevalent greenhouse gas, from cars and light trucks in Maine are likely to increase 40 percent between 1990 and 2020, according to the Natural Resources Council of Maine. The zero emissions program will help a little. Adopting California’s greenhouse gas emissions rule would help a lot, reducing carbon monoxide emissions by 11 percent. New York, Massachusetts, Connecticut and Rhode Island have also indicated an interest in implementing the California standards.

Proving that states won’t wait for federal action, Gov. Baldacci last week unveiled the state’s Climate Action Plan, which included 55 possible steps to reduce the state’s contribution to climate change. The goal of the plan is to reduce greenhouse gas emissions from Maine sources to 1990 levels by 2010, 10 percent below those levels in 2020 and by as much as up to 75 percent in the longer term.

One of the 55 steps suggested is adopting California’s vehicle emission standards, which are now tied up in court. With a lot of time and energy, Maine may reach its goals. Its task would be a lot easier if the federal government adopted stricter greenhouse gas emissions standards.