Despite nearly two decades of panicky reports about a planet melting down, only 35% of Americans think global warming “will pose a serious threat to you or your way of life in your lifetime,” according to a recent Gallup Poll.

The reaction of the environmental pessimists, along with the doomsters in the press, has not been to rethink their position but to redouble their scare tactics. A documentary movie chronicling Al Gore’s shrill campaign to approve his beloved Kyoto Treaty has just been released; Time magazine’s recent cover instructed us – once again – to “Be Worried. Be Very Worried;” and our oh-so-objective Big Media is providing tens of millions in free airtime for an Ad Council campaign proclaiming that if we fail to act, the end is … well, not exactly near, but not far away either.

One of the TV ads depicts a locomotive hurtling down the train tracks. An adult appears, saying that because global warming isn’t likely to have much impact for 30 years, it “won’t affect me.” Then he steps away to reveal a little girl in the path of the onrushing train. Message: If society doesn’t act now, we are dooming future generations.

Normal people, however, understand that the “precautionary principle,” often invoked by enviros as a reason to act before all the evidence is in, also requires us to take into account the distinct possibility that government will get things wrong. They may also remember the predictions of prominent scientists in the late 1960s that population growth would lead to mass starvation by the 1980s, or Hollywood’s pornographic delight in the horrors of “nuclear winter” if Ronald Reagan didn’t cave in to massive protests, fanned by Moscow, demanding unilateral disarmament in the 1980s.

Oh yes, and then there was the famous Newsweek cover story in 1975 asserting that meteorologists “are almost unanimous” that the earth was headed toward a new ice age.

What really frustrates the environmental pessimists – most of them left-wingers who have harshly criticized the Bush administration for plunging into Iraq before all the facts were known – has been the refusal of politicians to plunge into the global warming thickets without a clearer picture of the costs and benefits.

Congress has twice rebuffed measures by Senator McCain, R-Arizona, and Senator Lieberman, D-Conn., to cap carbon dioxide emissions. British Prime Minister Blair recently agreed that such measures are unrealistic. And the new government in Canada says it is “re-examining” its pledge to cut emissions just 6% below 1990 levels, as required by Kyoto.

Enviros love to point out that even some corporate executives have urged action, but the supposedly skeptical press seldom stops to inquire about their motives. In many cases they stand to profit from measures that would, in effect, greatly raise the costs to potential competitors of entering their business.

One of Time magazine’s sidebars unwittingly spells out another reason to “worry.” “Maybe we can begin by living more like the average Chinese or Indian – before they start living like us,” concludes the article, reflecting the belief among environmental elitists that the West’s “addiction” to economic growth is the source of all environmental ills.

The average person can thus be forgiven for hearing an entirely different train roaring down the tracks at that little girl. It’s labeled “solitary, poor, nasty, brutish and short” – a miserable existence that the Chinese and Indians have rejected for themselves.

Mr. Bray is a Detroit News columnist.