Today’s Wall Street Journal “Notable and Quotable” feature is on global cooling predictions in the 1970’s:
From Time magazine, June 24, 1974:
As they review the bizarre and unpredictable weather pattern of the past several years, a growing number of scientists are beginning to suspect that many seemingly contradictory meteorological fluctuations are actually part of a global climatic upheaval. However widely the weather varies from place to place and time to time, when meteorologists take an average of temperatures around the globe they find that the atmosphere has been growing gradually cooler for the past three decades. The trend shows no indication of reversing. [emphasis added] Climatological Cassandras are becoming increasingly apprehensive, for the weather aberrations they are studying may be the harbinger of another ice age.
Telltale signs are everywhere—from the unexpected persistence and thickness of pack ice in the waters around Iceland to the southward migration of a warmth-loving creature like the armadillo from the Midwest. Since the 1940s the mean global temperature has dropped about 2.7° F. Although that figure is at best an estimate, it is supported by other convincing data.
And then, the trend promptly reversed. For roughly the next 30 years average global temperatures trended slightly upward, and then stopped in about 1997 and have held fairly steady since. These are also trends that show no indication of reversing.
But when do trends ever show signs of reversing? I know when. Sometime after, perhaps years after, the reverse begins.
“Telltale signs are everywhere.” No, they were not. Only by hindsight can we now see what was about to happen. The only telltale sign that was obvious in 1974 was that the climatological Cassandras were making predictions without any sound basis of fact to support them because earth’s future climate is simply not predictable. Attempts to so with computer models is a fool’s errand. [Not only have all the computer predictions so far been wrong, It’s the Machine Epsilon problem, not just garbage in-garbage out, but good data in can also result in garbage out]
There now exists data that shows what really happened in the past, and the current trend does not support chicken little wild-eyed predictions of future climate catastrophe. If any telltale signs are everywhere today it is that global temperatures have stopped rising. For now, that is. Not until around 2045 will we know what the next 30 years will bring.
Yogi Berra’s wisdom: “I never make predictions. Especially about the future.”