Friday, August 7, 2009

Is "Cash for Clunkers" Good for the Environment?

There's been a lot of publicity about the cash for clunkers program - the government program that pays you to trade in an older vehicle getting less than 18 mpg for a new one that gets at least 22 mpg. But does the program really reduce global warming? The answer is: a very small amount. The problem isn't that the concept is bad, it just doesn't go far enough. But it still makes sense for most individuals to get rid of an old gas-guzzling clunker for a vehicle that getssignificantly more miles to the gallon.

Making a new car produces greenhouse gases, of course. If you trade in a clunker getting 18 mpg for a new car getting 22 mpg, it would take about 5 1/2 years of average driving to save the amount of greenhouse gases that went into manufacturing the new car, according to the dean of the Nicholas School of the Environment at Duke University, William Chameides, quoted on NPR here. After that, you would be reducing your carbon footprint. With trucks, it might take eight or nine years, Chameides says (trucks usually have more material in them and more greenhouse gases are produced in their manufacture). With the median age of cars on the road in the US older than ever at 9.4 years, and some of the new cars purchased getting more than 22 mpg, the net result is positive. However, the Associated Press calculated that the greenhouse gas savings from this year's cash to clunkers program would reduce the nation's greenhouse gas emissions by only a few hundredths of a percent, assuming 500,000 to 750,000 of the 260 million vehicles on the road in the US are traded in.

If you traded in a 20-mpg car for a 50 mpg hybrid, however, you'd make up for the greenhouse gases produced in manufacture in 20 months, according to Gil Friend of ClimateBiz. The greater the difference between the fuel economy of the old car and the fuel economy of the new car, the greater the savings in greenhouse gases. The longer you keep your new car the better for the environment, until there are newer cars whose efficiency is so great that it makes sense to trade in again. The savings with cash to clunkers is not as great as it could be - the original legislation required new cars purchased to meet stricter mileage standards to qualify - but it's a small step in the right direction. And it definitely makes sense for individuals to junk gas guzzlers and buy the most efficient vehicle they can, with or without a government program.
What's in your garage?
Stay cool,

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