Should the obese pay more for airline tickets?

It's one of the last untapped energy sources, and one in which the United States the world. It's not just renewable, but almost impossible to get rid of. We're talking about fat. At about 3,500 calories to the pound, a 300-pound American contains the energy equivalent in fat of roughly 15 gallons of gasoline. How long will we let this resource go unused?

OK, no one is proposing drilling fat people for fuel. But when most of us are looking over our shoulders at our carbon footprints, the obese seem a, well, fat target. Americans persist in the belief that it's fat people who consume more than their share of resources, rather than, say, movie stars flying private jets to Cannes. And since existing social disincentives to obesity haven't worked, people keep suggesting ways to enhance them, including weight surcharges for airplane tickets and higher rates for medical insurance.

It is indisputable that heavy people are more expensive to fly. A study concluded that the 10 pounds Americans gained on average during the 1990s required an additional 350 million gallons of fuel a year. But as much as the airlines could use the revenue, it's highly unlikely they will start charging passengers by weight, according to a spokesman for the Air Transport Association. Peggy Howell, of the National Association to Advance Fat Acceptance, agrees. "I don't believe people are willing to stand on a scale in public," she says. She happens to weigh 300 pounds, but points out that even thin people would probably object. One of the few experts who endorse a penalty for fat fliers is Laurie Zoloth, who heads the bioethics center at Northwestern University—but for her it's a question of fairness to the person in the next seat, rather than carbon emissions. In fact, Southwest Airlines already requires passengers who can't fit in a seat without raising the armrest to pay for two seats. (The extra cost applies only if the flight is oversold.)