For years, supporters of global warming alarmism have repeated an odd refrain: Even if we're wrong, we're right.

Sen. Timothy E. Wirth, D-Colo., said it in 1988, as the National Journal reported. "What we've got to do in energy conservation is (to) try to ride the global warming issue. Even if the theory of global warming is wrong, to have approached global warming as if it is real means energy conservation, so we will be doing the right thing anyway in terms of economic policy and environmental policy."

I regularly receive e-mails with similar arguments. Or, as one reader put it: "If global warming is not real, and we spend money trying to fight it, what harm will come of our mistake? Cleaner air? If global warming is real, and we do nothing, what harm will come of our laxity? On which side should we err?"

Savor, if you will, the lack of science in that argument. The global warming contingent loves to don the Mantle of Science as the reason to curb greenhouse gas emissions. But its backup argument is: It's OK if we're wrong, because we mean well.

What will come of the mistake of changing policies because of global warming alarmism?

The very question presupposes that the sacrifices that Americans will have to make are small.

Viewers of Al Gore's flick "An Inconvenient Truth" were warned of the dire changes on this planet and then were referred to a Website that tells people to buy compact fluorescent light bulbs, properly inflate their tires, drive less and turn off electronic devices when not in use. As if those changes would stop the predicted catastrophe.

Some of the most well-known global warming promoters are big-time energy guzzlers. Gov. Arnold Schwarzenegger, who signed landmark state global-warming legislation, has his Hummers and leases a private jet. A conservative think-tank, the Tennessee Center for Policy Research, reported that, despite their signature issue, the Gores burned 221,000 kilowatt hours last year, or 20 times the national average, in one of their three homes.

To global warming glitterati, the noble approach to the issue is to push for treaties, laws and regulations that make other people and other industries do the heavy lifting on energy conservation.

Last month, a United Nations conference in Vienna approved a nonbinding agreement directing industrialized nations to cut their emissions by 25 percent to 40 percent of 1990 levels by 2020.

If the United States were to sign onto such an agreement, Washington first would have to reduce emissions by some 15 percent just to reach 1990 levels. Then America could work toward the new goals. In effect, Americans would have to halve their greenhouse gas emissions in 12 years.

How do you do that?

As for me, while I am a global warming agnostic, I am not stopping anyone from taking the bus. Schwarzenegger and others have argued that new technologies can light the way. But those that exist cost too much, which means that only effective way to cut greenhouse gas emissions is to pass huge energy tax increases.

Newsweek columnist and economist Robert J. Samuelson, a reasoned voice on global warming, wrote that he supports gradually raising the gasoline tax of $1 to $2 per gallon. I wonder how many Californians would be willing to not only pay $4 or $5 for a gallon of gas but more for every commodity. And Samuelson is clear that his modest gas tax can't do much to reduce greenhouse gases.

America's sacrifices could be for naught, as long as China -- which is or is about to be the world's greatest generator of greenhouse gases -- is exempt from any global warming pact.

To go the distance supported by global warming alarmists requires big changes.

If the alarmists are right, the whole world will have to change and it will be onerous. If the global warming alarmists are wrong, much of the sacrifices they demand will have been for nothing.