In advance of his testimony Wednesday before the House Energy and Commerce Committee, Vice President Gore is using his Web site, www.algore.com, to ask Americans to send hundreds of thousands of e-mails to Congress urging “real action now to stop global warming.”

Recently, when the CEOs of GM, Ford, Chrysler, and Toyota testified before the committee, its chairman, Rep. John Dingell, a Democrat of Michigan, asked each CEO whether he would consider “a system which regulates the emissions of carbon dioxide from your vehicles.” Each CEO answered in the affirmative, but the details of such regulation, and the costs to consumers, are years away.

Mr. Gore will get a warm reception, but “real action” is doubtful. A carbon tax or a binding cap-andtrade regulation for carbon emissions could cripple the American economy and with it the aspirations of many politicians. America and her politicians are not yet ready for that form of sacrifice.

Mr. Gore, at a meeting of the United Kingdom National Association of Pension Funds, stressed that the short-term financial returns for companies that invest in environmentally friendly processes may be poor but should be profitable in the long run. This message is not likely to boost investor confidence.

While lecturing in London, Mr. Gore may have seen cheerful Britons believing that they were doing their part to stop global warming — by shopping.

At a growing number of supermarkets in Britain, consumers find a “carbon footprint” label on practically all goods. These labels are used voluntarily in Britain rather than by government requirements. The major British supermarket chains — Tesco, Sainbury’s, Marks & Spencer, Asda, and Waitrose — have plans to become more “green,” in this case meaning both environmentally sensitive and profitable. Many British shoppers, it turns out, care about the claimed (but likely unverifiable) differences in carbon emissions among different products.

Does an orange from Spain produce more carbon emissions than one grown in Florida? This metaphysical question has no right or wrong answer, but it seems to matter to many British consumers. No government is likely to develop legally defensible measurements of product carbon footprints for mandated labels. But private groups provide guesses, with impunity, to information-hungry British consumers.

British consumers are connoisseurs of socially aware voluntary labels on products. “Fair trade” labels reassure the consumer that workers in developing countries are not being exploited. The Forest Stewardship Council certifies products derived from sound forestry practices. The Marine Stewardship Council certifies for sound fishery practices. Not all labels are created by third-party certifications. For example, some produce and fish products have an air-freight label.

These and other voluntary labels help environmentally sensitive consumers make choices. You can still purchase carbon-gluttonous products such as aluminum foil or plastic wrap, but you might be met with a “tut-tut” from a cashier.

Retailers themselves compete actively for environmental support. Endorsements by Greenpeace and the World Wildlife Fund are cherished by Marks & Spencer to burnish its environmental credentials with the public; in America, Safeway or Kroger would be unsure of the positive value, if any, of endorsements by these or other environmental organizations.

Not so in Britain. Marks & Spencer asserts that it will “minimize energy use, maximize the use of renewables, and use offsetting as a last resort.” “Offsetting” means purchasing environmental credits to offset carbon consumption at home. That is exactly what Mr. Gore has done to atone for large energy bills in his Tennessee home. To a British consumer, “offsets” are a last resort, not the first choice for an environmentalist.

Wednesday, Mr. Gore will tell Congress that it must do something to stop global warming. The real challenge for Mr. Gore and those who believe in global warming is convincing American consumers that fighting global warming is worth the economic sacrifice. Only if consumers are convinced — and many are not — will American businesses and Congress follow suit.

A former FCC commissioner, Mr. Furchtgott-Roth is president of Furchtgott-Roth Economic Enterprises. He is organizing the seminar series at the Hudson Institute. He can be reached at hfr@furchtgott-roth.com.