With increasing acceptance of the reality of global climate change, interest groups of all stripes clamor to get in on the act. Some want to do good. Others want to do well, or to impose their notions of virtue on others. Our challenge is to devise sensible responses to global warming, while blocking "solutions" benefiting only their proponents.

For large corporations, environmental concerns present new marketing oppor-tunities. A perfect example is ethanol, for which agribusinesses energetically seek heavy public subsidies. Although they tout its benefits, the conversion of corn into fuel requires heavy inputs of energy, including natural gas based fer-tilizers, farm equipment, and transportation. According to a 2005 study by Cornell University and the University of California at Berkeley, turning plants such as corn, soybeans, and sunflowers into fuel uses much more energy than the resulting ethanol or biodiesel generates. According to Cornell ecology and agriculture professor David Pimentel, "There is just no energy benefit to using plant biomass for liquid fuel. These strategies are not sustainable."

Nevertheless, business and government leaders clamor for ethanol and other biofuels, although they have questionable environmental benefit and increase the prices of basic foods, such as corn tortillas, to the world's poor.

Another program endorsed by industrial users of energy is government capping of the overall use of carbon dioxide and other greenhouse gases (GHGs), and the trading of entitlements to GHG generation. This means that existing pol-luters would probably receive a windfall in the form of ownership of many billions of dollars in future pollution rights. There is less incentive to cut total pollution when one could sell rights to pollute.

Non-profit interest groups also invoke global warming to further their own agendas. "Smart growth" supporters use global warming as another cudgel against suburban and rural lifestyles. California attorney general Jerry Brown has sued San Bernadino, the nation's largest county in area, for not taking the "carbon footprint" of development into account in its 25-year land use plan. The result may be requirements for multifamily and smaller, more energy-efficient houses, and restrictions on driving.

In its purest form, regulation in the name of global warming is a moral crusade rather than a meaningful way of dealing with a serious problem that is consistent with individual liberty.

The Washington Post reported on July 18 that on a "leafy street in Northwest Washington, where Prius hybrid cars and Volvos are the norm," one man parked his Hummer. "It lasted five days on the street before two masked men took a bat to every window, a knife to each 38-inch tire and scratched into the body: 'FOR THE ENVIRON.'" As the owner pondered his SUV, he became "the target of a number of people who have driven by the crime scene in his upscale neighborhood and glared at him in smug satisfaction." According to a nearby resident, "The neighborhood in general is very concerned with the environment. It's more liberal leaning. It's ridiculous to be driving a Hummer."

The New York Times reported the previous day that Mayor Michael Bloomberg "lashed out at lawmakers" in the state capital, "accusing them of failing to take action against climate change and air pollution by shelving his plan to charge a fee to drivers entering the busiest parts of Manhattan."

Perhaps New York City could use a congestion tax. Some people are offended by Hummers and suburban houses, and are unmoved by those subsisting on corn tortillas instead of breakfasting on granola. Some noted environmental advocates live in huge houses and movie stars who decry materialism travel on private jets to exotic resorts.

But consumption is not evil. If we were to sit down like adults, we might forego symbolic measures and decide to pay the very steep price required to make a real dent in global warming. The best tool would be a carbon tax. The more energy you use, the more you pay. Pollution isn't grandfathered in. Those who like Hummers, or private jet vacations, could cut back on other forms of energy consumption or pay more. It's simple and it works. But it doesn't make us feel good and it isn't cheap. And that's why the carbon tax isn't on the 2008 political agenda.