Two weeks ago, we sparked a spirited Web debate on California's plan to target greenhouse-gas emissions from cars.

In one comment, someone calling himself Kyle suggested we adopt an automobile cap-and-trade program, like the one power plants face. Plants will have to stay below an emissions cap. If they can't, they will have to buy credits from cleaner competitors with emissions to spare.

Said Kyle: "A simple solution would be to apply carbon credits to fossil fuels like gasoline. Want to drive an SUV? Fine. If you go above your allotted carbon credits, then you pay some taxes to buy more. Don't like wasting carbon credits on an SUV? Buy a more fuel-efficient vehicle or get an SUV that runs on ethanol."

For many of you, that went over like a lead balloon. But you figured the chance of that happening was as remote as digging out from a blizzard in Carlsbad.

Maybe not.

Global warming is all the rage in Sacramento these days. And a lawmaker has proposed something that sounds very similar.

Assembly Bill 493 by Assemblyman Ira Ruskin, D-Redwood City, would have the California Air Resources Board set a range of acceptable carbon emissions that a quarter of new vehicles could meet. This would apply only to new cars beginning with model year 2011.

There would be no price change for cars within the acceptable range. Those who selected models exceeding the target would pay surcharges as high as $2,500, Ruskin said. Those choosing vehicles that emit less would get rebates up to $2,500.

Ruskin is accused of trying to play Robin Hood and steal from the rich to pay the poor.

"I don't agree with that," he said last week. "It's not about the people; it's about the cars. It's about giving consumers the incentive to purchase cleaner cars. The public pretty well decided last year in California that we wanted to tackle global warming. … and we can't realize our greenhouse-gas goals without dealing with the cars."

Ruskin said California cars pump out as much carbon as industrial sources.

Offering examples, Ruskin said sports cars such as the BMW Z8 and Dodge Viper likely would carry a surcharge, as would the big Ford Expedition sport utility vehicle and luxurious Lincoln Town Car.

The Ford Escape mid-size sport utility and Toyota Tacoma truck would not. The Saturn Vue, a small sport utility vehicle, would earn you a rebate.

Even a big vehicle would get you a rebate if it was a hybrid or ran on ethanol.

"It's based on how clean the car is, not how large it is," Ruskin said.