As the twentieth century drew to a close, the connection betweenhard scientific fact and public policy became increasingly elastic. Inpart this was possible because of the complacency of the scientificprofession; in part because of the lack of good science education amongthe public; in part, because of the rise of specialized advocacy groupswhich have been enormously effective in getting publicity and shapingpolicy; and in great part because of the decline of the media as anindependent assessor of fact. The deterioration of the American mediais dire loss for our country. When distinguished institutions like theNew York Times can no longer differentiate between factual content andeditorial opinion, but rather mix both freely on their front page, thenwho will hold anyone to a higher standard?

And so, in this elastic anything-goes world where science-ornon-science-is the hand maiden of questionable public policy, we arriveat last at global warming. It is not my purpose here to rehash thedetails of this most magnificent of the demons haunting the world. Iwould just remind you of the now-familiar pattern by which these thingsare established. Evidentiary uncertainties are glossed over in theunseemly rush for an overarching policy, and for grants to support thepolicy by delivering findings that are desired by the patron. Next, theisolation of those scientists who won't get with the program, and thecharacterization of those scientists as outsiders and "skeptics" inquotation marks-suspect individuals with suspect motives, industryflunkies, reactionaries, or simply anti-environmental nutcases. Inshort order, debate ends, even though prominent scientists areuncomfortable about how things are being done.

When did "skeptic" become a dirty word in science? When did a skeptic require quotation marks around it?

To an outsider, the most significant innovation in the globalwarming controversy is the overt reliance that is being placed onmodels. Back in the days of nuclear winter, computer models wereinvoked to add weight to a conclusion: "These results are derived withthe help of a computer model." But now large-scale computer models areseen as generating data in themselves. No longer are models judged byhow well they reproduce data from the real world-increasingly, modelsprovide the data. As if they were themselves a reality. And indeed theyare, when we are projecting forward. There can be no observational dataabout the year 2100. There are only model runs.

This fascination with computer models is something I understand verywell. Richard Feynmann called it a disease. I fear he is right. Becauseonly if you spend a lot of time looking at a computer screen can youarrive at the complex point where the global warming debate now stands.

Nobody believes a weather prediction twelve hours ahead. Now we'reasked to believe a prediction that goes out 100 years into the future?And make financial investments based on that prediction? Has everybodylost their minds?

Stepping back, I have to say the arrogance of the modelmakers isbreathtaking. There have been, in every century, scientists who saythey know it all. Since climate may be a chaotic system-no one issure-these predictions are inherently doubtful, to be polite. But moreto the point, even if the models get the science spot-on, they cannever get the sociology. To predict anything about the world a hundredyears from now is simply absurd.

Look: If I was selling stock in a company that I told you would beprofitable in 2100, would you buy it? Or would you think the idea wasso crazy that it must be a scam?

Let's think back to people in 1900 in, say, New York. If theyworried about people in 2000, what would they worry about? Probably:Where would people get enough horses? And what would they do about allthe horseshit? Horse pollution was bad in 1900, think how much worse itwould be a century later, with so many more people riding horses?

But of course, within a few years, nobody rode horses except forsport. And in 2000, France was getting 80% its power from an energysource that was unknown in 1900. Germany, Switzerland, Belgium andJapan were getting more than 30% from this source, unknown in 1900.Remember, people in 1900 didn't know what an atom was. They didn't knowits structure. They also didn't know what a radio was, or an airport,or a movie, or a television, or a computer, or a cell phone, or a jet,an antibiotic, a rocket, a satellite, an MRI, ICU, IUD, IBM, IRA, ERA,EEG, EPA, IRS, DOD, PCP, HTML, internet. interferon, instant replay,remote sensing, remote control, speed dialing, gene therapy, genesplicing, genes, spot welding, heat-seeking, bipolar, prozac, leotards,lap dancing, email, tape recorder, CDs, airbags, plastic explosive,plastic, robots, cars, liposuction, transduction, superconduction, dishantennas, step aerobics, smoothies, twelve-step, ultrasound, nylon,rayon, teflon, fiber optics, carpal tunnel, laser surgery, laparoscopy,corneal transplant, kidney transplant, AIDS… None of this would havemeant anything to a person in the year 1900. They wouldn't know whatyou are talking about.

Now. You tell me you can predict the world of 2100. Tell me it'seven worth thinking about. Our models just carry the present into thefuture. They're bound to be wrong. Everybody who gives a moment'sthought knows it.