You could get some green if you go green: President Obama is touting legislation that would pay drivers to turn in their gas-guzzling, exhaust-emitting cars for fuel-efficient vehicles.

So-called “cash for clunker” bills moving through the House and Senate would provide vouchers of $2,000 to $5,000 – depending on the age of the clunker, the fuel efficiency of the new car and where it was made – to buyers of greener automobiles. The old car parts would then be recycled. An incentive program in Germany that offered $3,290 to consumers who traded in their old cars hiked auto sales by more than 21 percent last month over the previous February, according to Rep. Betty Sutton (D-OH), who is sponsoring legislation on the issue.

“Such fleet modernization programs, which provide a generous credit to consumers who turn in old, less fuel-efficient cars and purchase cleaner cars, have been successful in boosting auto sales in a number of European countries,” Obama said yesterday during a White House speech on bolstering the sagging U.S. auto industry.

A bill Sutton introduced earlier this month would give consumers who turn in cars manufactured before 2001 vouchers of $3,000 if they buy vehicles assembled in North America with a minimum fuel efficiency of 24 miles per gallon; $4,000 if the new car is made in the U.S. and has a fuel efficiency of 27 miles per gallon or better; and $5,000 if the car is American-made and has a minimum fuel efficiency of 30 miles per gallon.

Similar legislation introduced in January by Sen. Dianne Feinstein (D-Calif.) would give consumers $2,000 toward the purchase of a new car if they hand over a model made in 1998 or earlier and a $4,500 voucher if they turn in a model manufactured in 2002 or later. That measure doesn’t specify that the car must be U.S.-made.

The program could potentially save tens of thousands of barrels of gasoline daily and reduce emissions of greenhouse gases and other pollutants, according to Feinstein.

Still, some research challenges that idea, arguing that improving energy efficiency (and therefore lowering its cost) may actually increase demand for that power — a so-called rebound effect. In the case of fuel-efficient vehicles, the amount of energy savings is actually 10 to 30 percent less than predictions because of that phenomenon, Frank Grotton, an analyst at the Washington, D.C. nonprofit National Council for Science and the Environment, wrote in a 2001 report.

How enticing will any "cash for clunkers" program be? The appeal of fuel-efficient vehicles tracks with the economy and the cost of gas, says Brett Smith, director of the automotive analysis group at the Center for Automotive Research in Ann Arbor. "It's driven for most people by fuel prices and economics," Smith tells "As incentive decreases, you find out what that true percent of the market is that’s buying for environmental passion than the economic incentive."

Meanwhile, sales of the Hummer – a symbol of gas guzzling at its greediest – fell by 50 percent last year, a drop that has manufacturer General Motors considering whether to retire or sell the brand (a decision was expected as early as today, but the company will take another few weeks to make one, according to Reuters). “It’s a brand that represents a lot of what people want to get away from,” Rebecca Lindland, an analyst with the research firm I.H.S. Global Insight, told the New York Times. “Even if gas prices are lower, it still kind of radiates conspicuous consumption. Hummer was suddenly perceived as all that’s wrong with America’s dependence on foreign oil.”

The enviro-hostile Hummer gets less than 10 miles per gallon of fuel, which may well be a key reason for its plunging popularity, the New York Daily News reported last summer.

Image by djshaggy via Flickr