When I was back in eighth grade, my science teacher, Mr. Malone, a brittle old man with a shock of white hair and a stern classroom demeanor, but a sharp sense of humor, had made a banner that ran across the top of the blackboard. It read: “If you can’t measure it, it doesn’t exist.”

I used to ponder at that admonition every morning back in 1962, and its message did sink in, as I think it did in the minds of every student in the class who wasn’t just falling asleep in the back of the room, or idly daydreaming. Students in that class went on to become brain surgeons, genetic engineers, writers, computer scientists, horticulturalists and lawyers. I don’t think too many of us are conspiracy theorists.

Malone encouraged me and my classmates to pursue a science track. He selected a fellow student and me for an experiment, shifting us midway through the fall term to an 11th grade advanced physics class, where we learned to calculate vectors, understand wave behavior and the peculiar nature of light, and where we experimented with electricity (I learned its power when, during a boring lecture, I absent-mindedly stuck two straight pins into the electric outlet on my science desk and crossed them, causing a flash and pop, burning the outlet cover and my fingers, and casting the whole classroom into darkness). Sometimes I was lost, but most of the time, I was simply captivated, learning about the inner workings of the atom and the universe.

The public school I attended was excellent, featuring a number of iconoclastic teachers, who taught us to question, not just to memorize.

Sadly, I have learned that this is not the norm in American education, which many explain why the country is so prone to conspiracy theories.

What can we expect when polls show that only 39 percent of Americans believe in evolution (no surprise since fewer than 33 percent even know about DNA and its role in heredity)? What can we expect when one in five Americans, or about 20 percent of us, think that the sun revolves around the earth, or that 55 percent believe that they are protected by a “guardian angel”?

Conspiracy theories abound where people are fearful and ignorant. There is the conspiracy theory that Americans never really landed on the moon, the conspiracy theory that Jews run the world, the contradictory conspiracy theory that the Freemasons or Opus Dei run the world, the conspiracy theory that President Obama is a secret Muslim born in Kenya. The list goes on and on.

I’m not saying there are not good reasons for considering some conspiracy theories. Certainly the assassination of President John F. Kennedy in 1963 was more complicated than the work of one man, Lee Harvey Oswald. Too many things had to work perfectly, and there are too many conflicting pieces of evidence, from the poorly adjusted sight on his gun to the Zapruder film and the alleged trajectory of one incredibly destructive “magic” bullet, for the official story to work. Ditto the assassination several years later of Martin Luther King.

Nor, or course, is the official story of the 9/11 attacks credible, and indeed even the participants in the 9/11 Commission are now refusing to stand by the commission’s conclusions about what happened. There are too many gaping holes, from how planes hitting the tops of buildings and creating fires that were far below the melting point of steel could have caused those buildings to dissolve into dust from the bottom up to why another building, not hit by any plane, would collapse in exactly the same fashion for no reason.

But not accepting an official explanation is different from adhering to a full-blown conspiracy theory, and Americans seem amazingly inclined to do the latter.

The most stunning example of this is the popularity of the global warming conspiracy theory.

Despite all the terrifying evidence before our eyes–the rapid disappearance of the North Polar ice cap, the rapid melting of the Greenland ice sheet, the shrinking back of mountain glaciers all over the world, the frightening acidification of the upper layer of the global oceans, the measurable and accelerating rise in sea levels, and the thousands of years of data on carbon dioxide levels in the atmosphere that can clearly be linked to temperature changes around the world, only half of Americans even believe that global climate is changing, and even fewer, just 36 percent, believe that the rising global temperature is caused even in part by human activity. Even more astounding is the fact that the number of Americans who believe the earth is heating up has fallen over the last few years from 77 percent to 51 percent.

Parallel to this is a growing support for an elaborate conspiracy theory that postulates that governments around the world, in collusion with virtually the entire scientific community, are working collectively to make up and promote a bogus story about global warming.

With other conspiracy theories, from the swine flu vaccination conspiracy to the lunar landing hoax, there is little need for concern. People have their belief system and go about their lives harmlessly. But with the climate change conspiracy, there is a terrible danger that it is leading to government inaction that could ultimately doom the human race, and indeed many of the earth’s myriad life forms, to extinction.

Let’s look at what the climate change conspiracy advocates are saying. They argue that the governments of Europe, of the US, of Canada, of China and India, and indeed of much of the rest of the world—governments that rarely agree on anything, I might point out—are acting in concert to promote a bogus claim that the earth is heating up because of man-made release of carbon dioxide into the atmosphere.

They claim that this conspiracy is being supported by the almost universal connivance of the world’s scientists, who are collectively falsifying data and hiding countervailing data. And all this is happeningthey assert, despite the almost universal opposition of the world’s corporations, most of which, we know, are resisting having governments take any serious action to combat climate change, and in many cases (look at the US Chamber of Commerce), are actively challenging the whole notion of climate change.

To believe in such a far-reaching conspiracy theory, one would have to first deny all the evidence before our eyes. But then one would also have to believe that the US, China, and Europe, as well as other countries, are in league. You would also have to assume that thousands of tenured scientists—a group with a disproportionate number of large egos and people with a penchant for disputation and controversy, I might add—are all working in concert to bury information and create a false theory.

Finally, you would have to believe that all this effort is being made in order to pursue an economy-crippling strategy of making fossil fuels more expensive that is directly in opposition to the wishes of virtually the entire capitalist system.

When, I have to ask, has the US government ever acted deliberately against the interests of the major capitalist enterprises? When, except during revolutionary moments, have any nations acted against the wishes of the assembled commercial interests within their borders? The short answer is: never.

Unless you think the Jews, or alternatively the Freemasons or Opus Dei or the Federalist Society, or maybe all these disparate groups together, are behind this vast conspiracy, and have successfully terrorized and bribed the tens of thousands of scientists and government officials into complicity, the idea of a conspiracy so huge and far-reaching is simply laughable.

And yet with almost half of Americans ready to believe it, the corporate media, eager for ratings, are playing along, giving equal billing to the global warming deniers. Just last night, ABC News anchor Charlie Gibson offered a story on climate change that featured competitor Fox TV’s ardent climate change denier and conspiracy theorist Glenn Beck as a suppsedly credible advocate for the argument that global warming is an elaborate hoax.

We might as well be watching news stories about how we’ve all been duped into believing that the earth revolves around the sun, or that, god help us, the damned thing is round.

The truth is, if there is a conspiracy regarding climate change, it is a conspiracy by our government to minimize the threat (we saw that concretely with the attempt by the Bush administration to muzzle climate scientists like NASA’s James Hansen), avoid taking serious action, and pretend that the actions being proposed, like “cap and trade,” will solve the problem.

As I sit here in southeastern Pennsylvania on December 10, looking out at the green grass on my lawn, which has yet to feel a hard frost just two weeks before Christmas, I’m reminded of Mr. Malone’s old banner: “If you can’t measure it, it doesn’t exist.” The corollary is clearly: “If you can measure it, it does exist.”

Dave Lindorff is a Philadelphia-based journalist. He is author of Killing Time: An Investigation into the Death Penalty Case of Mumia Abu-Jamal (Common Courage Press, 2003) and The Case for Impeachment (St. Martin’s Press, 2006). His work is available at thiscantbehappening.net