Skeptics say that many scientists in the 1970s predicted an ice age. By saying this they hope to create the impression that scientists are as wrong today as they were back then.
In the thirty years leading up to the 1970s, available temperature recordings indicated a very slight cooling trend. Also, air pollution from fossil fuel burning was thought to have been reflecting sunlight thus cooling off the earth. As a result, a few scientists suggested that the current warm period after the last ice age could end, which might result in the Earth plunging into a new ice age over the next few centuries.
The media picked up on this and a long list of local papers, weekly magazines, and television reports trumpeted reports of a coming ice age.
At the same time, however, a much greater number of scientists published contradicting studies. Their papers showed that the growing amount of greenhouse gases that humans were putting into the atmosphere would cause much greater warming – warming that would exert a much greater influence on global temperature than any possible natural effects.
From 1965 to 1979, there were 5 times as many scientists predicting global warming as there were those predicting global cooling – an 83% to 17% difference (Excluding those who were neutral). By the 1980s, the predictions about ice ages had ceased, due to the overwhelming evidence brought out in an increasing number of reports that warned of global warming.
In 2008 the American Meteorological Society’s (AMS) published a paper The Myth of the 1970s Global Cooling Scientific Consensus (Abstract) by Peterson, Conolly, and Fleck. In the abstract they stated:
An enduring popular myth suggests that in the 1970s the climate science community was predicting “global cooling” and an “imminent” ice age, an observation frequently used by those who would undermine what climate scientists say today about the prospect of global warming. A review of the literature suggests that, on the contrary, greenhouse warming even then dominated scientists’ thinking as being one of the most important forces shaping Earth’s climate on human time scales.
In the heading of their paper (PDF) they state:
There was no scientific consensus in the 1970s that the Earth was headed into an imminent ice age. Indeed, the possibility of anthropogenic warming [human-caused] dominated the peer-reviewed literature even then.
Figure 1: American Meteorological Society: The Myth of the 1970s Global Cooling Scientific Consensus – Page 1032.
Unfortunately, the small number of predictions of an ice age appeared to be much more interesting to the media than the majority that predicted global warming, so it was those sensational ‘Ice Age’ stories that they reported on. Thus Skeptics take advantage of that in order to confuse the issue.