Gov. Arnold Schwarzenegger signed legislation Tuesday that attempts to ease greenhouse gas emissions by giving priority to transportation projects that limit commutes and curb urban sprawl.

Supporters said the legislation is needed to help implement a 2006 law that requires California to reduce its greenhouse gas emissions to 1990 levels by 2020.

The bill requires the state Air Resources Board to set regional targets for reducing greenhouse gas emissions from cars and light trucks and directs regional planning agencies to develop land-use strategies to meet those targets.

Cities and counties will not have to implement those plans, but they could lose transportation funding if they don’t.

“This bill is designed to have new growth be much more transit-friendly and have housing be closer to employment centers,” said William Craven, an aide to bill author Sen. Darrell Steinberg. “So (transportation) projects that help to reduce commutes and sprawl are the ones that float to the top and get funded.”

The bill also includes an additional incentive for cities and counties to comply. It relaxes environmental reviews for housing projects that comply with the so-called sustainable communities strategies that will be developed by regional planners.

Craig Noble, a spokesman for the Natural Resources Defense Council, an environmental group that supports the bill, said it is “definitely a carrot approach.”

“Actual land-use zoning decisions are local decisions, so the state can’t say, ‘You must do this,’” he said. “What the state can do is make it very desirable for communities to plan more compact, livable development by giving them incentives.”

By Steve Lawrence - Associated Press Writer