A bill introduced last week by Assemblyman Ira Ruskin, D-Redwood City, aims to provide rebates for new car buyers in California who purchase vehicles with lower emissions, a spokesman for Ruskin said.

Under AB 493, the Clean Car Discount Act of 2007, one-time rebates would be offered to California consumers who purchase cleaner vehicles, paid for by one-time surcharges that would be imposed on the purchase of new vehicles with higher emissions.

AB 493 is seen as an "effective market-based" tool to implement the emissions reduction standards set into law last year under AB 32, the California Global Warming Solutions Act, according to Ruskin's spokesman Nate Pinkston.

The Global Warming Solutions Act, signed into law by Gov. Arnold Schwarzenegger in September, calls for California greenhouse gas emissions to be reduced to 1990 levels by the year 2020.

According to Ruskin's office, that goal can't be met without addressing greenhouse gas emissions from vehicles.

"Since transportation accounts for over 40 percent of global warming emissions in this state, we need effective tools to avert the worst consequences of climate change now," Ruskin said in a statement released Monday. "We cannot meet AB 32's global warming mandate without addressing emissions from the vehicles we drive," he said.

The bill's promoters hope consumer incentives -- rebates up to a maximum of $2,500, depending on a new vehicle's emissions levels -- will increase demand for low-polluting vehicles and cause manufacturers to respond with greater production.

Surcharges for new vehicle customers could also reach up to $2,500 for the highest-polluting vehicles.

The bill's authors estimate that 40 to 45 percent of new vehicles could be eligible for a rebate, and 20 to 25 percent would be unaffected, leaving 30 to 40 percent that would be assessed a surcharge, which they claim would ensure that consumers still retain the ability to choose while moving the industry as a whole toward greener pastures.