Alan Caruba, in a piece titled The High Cost of Climate Lies, which is available at http://www.usadaily.com/article.cfm?articleID=132147 tries to counter the claim that human action is responsible in some measure for climate change. He cites a number of scientists who are critical of this claim. One of them is Dr. Vincent Gray, a New Zealand-based climate scientist, but the reasoning he cites is very curious. Dr. Gray, he writes, claims that “No average temperature of any part of the earth’s surface, over any period, has ever been made.” And so, “If the earth’s “average temperature” cannot be determined, how can you know that it’s dramatically heating? How can you predict anything about an unknown?”

The curious thing about this reasoning is that averages are phantom numbers that nothing ever depends upon. What matters so far as climate change is concerned is not whether the average temperature of the earth is rising, but whether the temperature at the poles and on mountain tops where glaciers are locates are rising. For if the ice and snow at these places melts away, humanity is in for some difficult times. That a recognized scientist should make a claim based on the unknown average temperature of the earth is dubious at best. Either Mr. Caruba has misunderstood Dr. Gray’s claims or Dr. Gray’s recognition as a prominent scientist is questionable.

That the earth’s average temperature is irrelevant can easily be demonstrated. Consider the following sequence of ten terms: 1, 3, 5, 7, 9, 10, 8, 6, 4, 2. The average of this sequence is 5.5. Now consider this sequence: 3, 3, 5, 7, 8, 9, 7, 6, 4, 3. The average of this sequence is also 5.5. Now suppose the first and last terms in the both sequences represent the temperature at the poles before and after global warming was noticed. Clearly, the temperature at the poles has risen while the average temperature has remained the same. As a matter of fact, it is easy to show that the temperature at the poles can have risen while the average has gone down. Look at this sequence: 3, 2, 4, 6, 8, 9, 7, 5, 4, 3. When this sequence is compared to the first, the terms representing the temperature at the poles have risen but the average had decreased to 5.1. Certainly any reputable scientist would understand enough about averages to have known the point that I have just demonstrated.

Mr. Caruba then writes this: “The IPCC has depended on computer climate models for its claims and there is now a volume of papers demonstrating how they have repeatedly been proven to be inaccurate. As Dr. Gray points out, if you cannot validate these models as actually capable of making predictions, ‘no self-respecting computer engineer would dare to make use of a model for prediction.’”

But think about this for a moment. The National Weather Service uses computer models, absolutely none of which is accurate, to predict the weather. Yet those predictions, while never absolutely accurate are certainly useful. All of us rely on them every day. They tell us when to carry raincoats and umbrellas, when to wear heavier clothing, when to get sanding trucks and snowplows ready, even when to evacuate people from areas threatened by hurricanes. Would it be reasonable for anyone to suggest that we should abandon these predictions because the models “have repeatedly been proven to be inaccurate”? 

It has always been a puzzle to me why people who are successful in some intellectual professions such as some branches of the physical sciences and all branches of the social sciences can engage is egregious reasoning when a thesis contradicts their cherished beliefs. Examples of such reasoning are easy to find, especially when the theses these “scientists” find objectionable have economic consequences. The critics of global warming are all worried about the costs of making the societal changes that countering global warming requires, but they refuse to even consider the costs that will be incurred if global warming is real and nothing is done to reduce or stem it. These people, somehow or another, allow ideology to trump reason.

No one knows for sure, of course, what the cause of global warming is. Is global warming caused merely by changes in the earth or the solar system over which we have no control, or is it caused by the huge amount of greenhouse gasses that we have been pumping into the atmosphere? No one knows, but we’d better hope that our practices are at least a major part of the problem, for if they aren’t, life on this planet may be doomed.