Those of us old enough to remember the 1970s sometimes think of it as the era of the bad disaster movie. Well, get ready for some cinematic déjà vu.
Sure, the upcoming film "The Day After Tomorrow" has a bigger budget and better special effects. But it flaunts the same lack of scientific credibility as, say, "Jaws" once did.
This time the culprit is carbon dioxide (CO2), a greenhouse gas we exhale every time we breathe. CO2 is also produced when we burn fossil fuels.
In the film, CO2 causes global warming. An Antarctic ice sheet melts. The oceans cool and the Gulf Stream stops. A massive summer snowstorm drowns much of North America under hundreds of feet of snow. No one is prepared for these changes, since they happen over just three days.
It gets worse. Eventually, the ice melts and inland areas flood. Ireland endures hurricanes while huge hailstones pelt Japan.
Whew. It's enough to make you want to hold your breath. Except it's all hot air.
The entire scenario hinges on shutting down the Gulf Stream, the warm ocean current that flows from west to east. But that couldn't happen. In a recent letter to Nature magazine, MIT professor Carl Wunsch points out, "the occurrence of a climate state without the Gulf Stream any time soon -- within tens of millions of years -- has a probability of little more than zero."
Still, the opinion of real experts such as Wunsch isn't enough to silence self-proclaimed experts such as former presidential candidate Al Gore. He says the film "presents us with a great opportunity to talk about the scientific realities of climate change," which he claims is "an emergency that seems to be unfolding in slow motion, but actually is occurring very swiftly -- not as swiftly as the movie portrays, but swiftly in the context of human history."
Well, let's keep Gore's "human history" in context. After all, Galileo didn't invent the thermometer until the 1590s, and we've been keeping detailed temperature records for only the last 100 years or so.
The only thing swift about global warming is how swiftly it's replaced the idea of global cooling. As recently as the 1970s scientists were worried about another ice age.
"During the last 20 to 30 years, world temperature has fallen, irregularly at first but more sharply over the last decade," the National Science Board announced in 1974. "Judging from the record of the past interglacial ages, the present time of high temperatures should be drawing to an end ... leading into the next glacial age."
That prediction hasn't worked out. So there's reason to be skeptical when a group such as moveon.org tries to stir up fear by handing out flyers warning that "global warming isn't just a movie, it's your future."
Let's set the rhetoric aside and look at the facts. The average temperature measured at the earth's surface has risen about one degree Fahrenheit in the last 100 years. But satellite measurements haven't shown a comparable trend and, in fact, show a slight cooling in the last 20 years. So while global warming may be a problem, and we should keep studying it, it's too soon to take radical, and expensive, steps.
That's why it's important to have think tanks such as the Competitive Enterprise Institute. For 20 years now, CEI has been dedicated to providing sound science and debunking the myths spread by environmental extremists.
The fact is, in order to bring down CO2 emissions, we'd have to shrink the global economy. In 2001, for example, greenhouse gas emissions declined by 1.2 percent, mostly because of a 3.5 percent decline in economic growth. Small wonder the Senate voted down the infamous Kyoto Accord 95-0.
This summer, millions of Americans will sit in air-conditioned movie theaters and watch a frightening film. But the real risk today isn't global warming -- it's that we'll overreact and damage our economy in an unnecessary attempt to prevent climate change.
Let's hope cooler heads prevail.
Ed Feulner is the president of The Heritage Foundation (heritage.org), a Washington-based public policy research institute.