As one of the country’s leading conservation organizations, the Sierra Club often asks the Environmental Protection Agency to enforce federal laws to protect the environment. Now, the club wants the Internal Revenue Service (IRS) to step up its auditing efforts on certain SUV owners and to help the environment in the process.

In a press release last month, the San Francisco-based Sierra Club explained its directive to the IRS. The club contends that a tax loophole encourages small-business owners to buy gas-guzzling SUVs that contribute to global warming.

The IRS allows small businesses a tax break of up to $25,000 for a vehicle that weighs more than 6,000 pounds and is used for business purposes 50 percent of the time. The Sierra Club argues that the law was meant to include work trucks and delivery vans, not sport utility vehicles, which often weigh more than 6,000 pounds.

The club says that some small-business owners take advantage of the law by buying SUVs for their personal use. Daniel Becker, director of the Sierra Club’s global warming and energy program, said, "the IRS needs to ensure that this bizarre loophole isn't abused, putting even more gas-guzzlers on the road."