Britain's Channel 4 has produced a devastating documentary titled "The Great Global Warming Swindle." It has apparently not been broadcast by any of the networks in the United States. But, fortunately, it is available on the Internet.

Distinguished scientists specializing in climate and climate-related fields talk in plain English and present readily understood graphs showing what a crock the current global warming hysteria is.

These include scientists from MIT and top-tier universities in a number of countries. Some of these are scientists whose names were paraded on some of the global warming publications that are being promoted in the media -- but who state plainly that they neither wrote those publications nor approved them.

One scientist threatened to sue unless his name was removed.

While the public has been led to believe that "all" the leading scientists buy the global warming hysteria and the political agenda that goes with it, in fact the official reports from the United Nations or the National Academy of Sciences are written by bureaucrats -- and then garnished with the names of leading scientists who were "consulted," but whose contrary conclusions have been ignored.

There is no question that the globe is warming but it has warmed and cooled before, and is not as warm today as it was some centuries ago, before there were any automobiles and before there was as much burning of fossil fuels as today.

None of the dire things predicted today happened then.

The British documentary goes into some of the many factors that have caused the earth to warm and cool for centuries, including changes in activities on the sun, 93 million miles away and wholly beyond the jurisdiction of the Kyoto treaty.

According to these climate scientists, human activities have very little effect on the climate, compared to many other factors, from volcanoes to clouds.

These climate scientists likewise debunk the mathematical models that have been used to hype global warming hysteria, even though hard evidence stretching back over centuries contradicts these models.

What is even scarier than seeing how easily the public, the media, and the politicians have been manipulated and stampeded, is discovering how much effort has been put into silencing scientists who dare to say that the emperor has no clothes.

Academics who jump on the global warming bandwagon are far more likely to get big research grants than those who express doubts -- and research is the lifeblood of an academic career at leading universities.

Environmental movements around the world are committed to global warming hysteria and nowhere more so than on college and university campuses, where they can harass those who say otherwise. One of the scientists interviewed on the British documentary reported getting death threats.

In politics, even conservative Republicans seem to have taken the view that, if you can't lick 'em, join 'em. So have big corporations, which have joined the stampede.

This only enables the green crusaders to declare at every opportunity that "everybody" believes the global warming scenario, except for a scattered few "deniers" who are likened to Holocaust deniers.

The difference is that we have the hardest and most painful evidence that there was a Holocaust. But, for the global warming scenario that is causing such hysteria, we have only a movie made by a politician and mathematical models whose results change drastically when you change a few of the arbitrarily selected variables.

No one denies that temperatures are about a degree warmer than they were a century ago.

What the climate scientists in the British documentary deny is that you can mindlessly extrapolate that, or that we are headed for a climate catastrophe if we don't take drastic steps that could cause an economic catastrophe.

"Global warming" is just the latest in a long line of hysterical crusades to which we seem to be increasingly susceptible.