The recent press coverage of Al Gore’s global warming movie “An Inconvenient Truth” is a superb, if inadvertent example of our collective inability to distinguish scientific fact from science fiction. Because many of us lack the technical understanding, and background, necessary to unravel the intricacies behind global warming, we simply accept at face value what is presented by the media.

“Inconvenient Truth” is typical of most contemporary coverage of global warming. The essence of the film is that there is irrefutable evidence that mankind is causing the Earth’s temperature to increase, that unspeakable disasters are imminent unless we act immediately, and that there is scientific consensus on the matter. So, the argument goes, mankind is causing severe storms, melting icecaps and changing ocean currents. And to anyone who would take issue with these claims, be warned that scientists overwhelmingly stand unified in their agreement. Armageddon! Can it get any worse than this?

In fact, perhaps things aren’t as bad as they seem..

First, not all scientists agree that the Earth is warming substantially due to mankind’s activities, or that the warming occurring is dangerous. There are thousands of peer reviewed papers written on topics related to global warming. Of the few dozen or so that I’ve read, most present data simply, analyze the data and draw conclusions based on the analyses. There is little, if any editorializing on the subject, and rarely, if ever do the authors express strong support for or denial of the proposition that “man is causing the Earth’s temperature to increase.” To my knowledge, no one has assembled a grand tally recording exactly which brave scientists endorse the theory of man-made global warming, and which of their brethren stand in stubborn opposition.

What about the evidence for global warming? It’s an exceedingly straightforward matter to find information on the subject. Most of the easily available material is predictably formulaic, reciting “obvious” evidence of global warming (warm days, melting icecaps, etc.), followed by claims that mankind’s generation of carbon dioxide is the cause, and concluding with an appeal to take decisive action now. Case closed. However, there is a large body of scientific information that differs considerably from what we are presented with in the press and on television. Here we learn that there are many natural causes of global climate change, including these:

• Plate tectonics (movement of the Earth’s crust)

• Variations in sun’s radiation

• Variations in Earth’s orbit around the sun

• Precession of Earth’s orbit on its axis (Earth slowly wobbles as it rotates)

• Cosmic rays (particles hitting Earth from outer space)

• Comets, meteors hitting Earth

• Volcanic activity

• Decay of naturally occurring radioactive isotopes inside Earth

These variables profoundly affect Earth’s climate. In fact, much of Earth’s climactic variability on geologic time scales can be statistically accounted for by these factors. By contrast, mankind’s influence may be immeasurably small. Contrary to popular opinion, scientists are still robustly debating these areas.

How do we know for certain that we are headed for disaster? After all, since predicting next week’s weather accurately is not easy, how can we be sure that rising sea levels will inundate our cities when the icecaps “inevitably” melt in a hundred years? Current predictions of Earth’s climate change are based on complicated computer models. There are in fact dozens of such models, and all make widely ranging predictions. Each model contains important parameters or “tuning factors” that tell the model how sensitive the future climate is to various atmospheric and oceanic conditions. Published studies documenting large uncertainties in these model parameters are readily available. Uncertain model parameters lead to uncertain results, which is another way of saying that the predictions made by the climate models are unreliable.

It’s further interesting to note that our climate models are based on a mere 150 years of Earth’s history. From this tiny slice of time the models purport to provide a thorough understanding of a planet that is 4.5 billion years old. This is equivalent to a doctor examining a 50-year-old patient for 35 seconds and saying that everything about the patient’s health is now known for certain – a clear absurdity.

Can We Do Anything?

What if we assume that mankind, by creating carbon dioxide, is indeed causing the Earth’s temperature to increase? What should we do? One course of action is for us to collectively decide what temperature the Earth should be (not too hot, not too cold) and to keep it there by either curtailing our CO2 emissions (if Earth is too hot) or increasing CO2 emissions (if Earth is too cold). Effectively, we would use CO2 emissions to keep the Earth’s temperature where we want it, despite the fact that there are huge natural driving forces conspiring against us. Can this be done? Using some of the (admittedly inaccurate) simulation parameters discussed in the previous paragraph, it can be roughly calculated that in order to control Earth’s temperature in this way, we would need to stop all industry for many years for a global cool-down – all factories, all electricity, all cars, trucks, planes, everything. Warming the Earth when it gets too cold would require the opposite – running all industries at full blast for many years. It would be a bit like using a hairdryer to try to control the temperature in your entire house in rain or shine, summer or winter – not impossible, but very hard.

There are reasonable estimates showing that the total cost to the world’s people if we do nothing to stop global warming would be $4.8 trillion (rising sea levels lead to loss of land, etc). By contrast, the cost to limit the Earth’s temperature increase to 1.5 degrees centigrade is estimated to be $37.6 trillion (e.g. reduced economic activity leads to lower quality of life in all parts of the world, including Third World countries). Clearly there must be a balance between doing nothing, and doing too much.

What about the moral implications of how we address global warming? Implementing the Kyoto treaty would cost an estimated $150 billion per year (published studies), and would reduce the warming trend of the Earth by a tiny amount. By contrast, UNICEF estimates that it would cost $70 billion per year to provide healthcare, education, clean water and sanitation to Third World countries, thus saving 2 million lives per year. Stated another way, if we had $150 billion to spend to make the world a better place, why would we spend it enforcing the Kyoto protocol when we can use the same money to save the lives of 2 million people per year by improving their living conditions?

(Mr. Korchinski is a chemical engineer with 30 years of industry experience and a background in mathematical modeling and statistics. He currently runs Montecito-based Advanced Industrial Modeling Inc., providing technology and services to his industrial customers to improve the operational efficiency of their plants. Bill has lived in Montecito for 14 years with his wife, Cynthia, and their two sons, Alex and Scott. He can be contacted at bill.korchinski@aimod.com.)