Conservative Advocate: Global climate has always fluctuated
The central argument of global warming alarmists is that, in the past 40 years of human economic activities (notably the burning of fossil fuels such as oil and coal) have added huge new quantities of carbon dioxide to the earth’s atmosphere, resulting in a small-but-perceptible increase in its temperature. This increase, they warn, is bound to have big and largely negative consequences for life in general, and human life in particular, over the next few decades. Among these, depending on the computer model adopted and the amount of warming it forecasts, are everything from warmer winters and hotter summers to the melting of the polar icecaps and a rise in mean sea level that will inundate coastal cities everywhere.
Now, nobody doubts that human activity has to some extent increased the amount of carbon dioxide in the atmosphere, and will continue to do so. The argument is over the extent. Natural causes are, and will continue to be, responsible for the vast majority of the carbon dioxide in the atmosphere. But the alarmists insist that the human contribution will be substantial, and must be cut back immediately at immense economic cost, if future generations are to be spared untold suffering.
To the layman, this argument sounds all too plausible. We are accustomed to moderate fluctuations in global temperature, but if any year turns out to be, on average, unusually hot or unusually cold, or has an unusual number of hurricanes or tornadoes, many people are easily convinced that something rare and dangerous is going on and must be stopped if possible.
What the average person doesn’t realize is how sharply global temperatures have varied even within historical times, let alone over longer periods. In the 1600s, for example, Europe experienced what was called “the Little Ice Age.” The canals of Venice froze over solid. Six hundred years earlier, on the other hand, Vikings pressing westward across the North Atlantic came upon a huge island so verdant they called it “Greenland.” There were no newspapers around in those days to scare the public with predictions of “global warming” or “global cooling,” however, let alone any substantial human contributions to the carbon dioxide in the atmosphere. Temperatures returned, in due course, to what we like to think of as normal.
Over longer periods, the world’s climatic fluctuations have been downright hair-raising. It seems likely that we are currently in a warm spell between two ice ages. The last one ended about 10,000 years ago, and there’s no reason to suppose there won’t be another in a few more thousand years. If so, and if the great glaciers reappear over the northern half of the globe, the sight of a mile-high wall of ice heading south toward Chicago will certainly be enough to focus Mayor Richard Daley’s mind that day.
Meanwhile, however, there is evidence that the relatively minuscule effects of “global warming,” whatever they are, are simply being overwhelmed by larger phenomena that have been going on for millions of years. In an article in Science, professor John Stone of the University of Washington in Seattle reports that the West Antarctic Ice Sheet appears to have been retreating steadily, at a rate of about 2 inches per year, for the past 10,000 years, without any help whatever from mankind. If the sheet melts entirely, Stone says, global sea level could rise by as much as 16 feet, inundating many islands and coastal areas. The point is that global temperature fluctuations are an old, old story, in which relatively brief cycles of warming and cooling recur within longer swings of cooling and warming.
There is nothing we can do about this — certainly a 10 percent reduction in the amount of carbon dioxide burped into the atmosphere by mankind would have no effect worth mentioning, save on the millions whose livelihoods would be imperiled by the cutback. Fortunately, the major climatic fluctuations occur over centuries and millennia, allowing us to adjust to what we can’t prevent.
(William Rusher is a Distinguished Fellow of the Claremont Institute for the Study of Statesmanship and Political Philosophy.)