Only some 40 years ago, the coming cataclysm, according to government scientists, was a pending ice age which would destroy much of the world as we know it.
It's interesting to read through the period literature. I'm currently reading the 1962 book, World of Ice, by geologist James L. Dyson. Dyson doesn't strike the sensationalist tone of his then-contemporaries, but he did ring the alarm bell, and outlined the popular methods floated to trigger a desired warming of the atmosphere.
Dr. H. Wexler of the U.S. Weather Bureau proposed creation of a huge ice cloud which would theoretically reduce the return of infrared radiation to space and thus warm the atmosphere. The ice cloud would be created by, say, the explosion of 10 nukes (10 megatons each), deep in the Arctic Ocean. However, the longer-term result, Wexler said, would be increased glacier growth and a new ice age. Oops!
- Warming up Hudson Bay with atomic-powered heaters.
-Pumping cold Arctic water into the Bering Sea.
Dyson predicted that Chicago would eventually become a "city of the Subarctic." "Most geologists believe that we are still in the ice age and many of them are of the opinion that vast sheets of ice will again spread over North America and Europe. There are some data to support this view, very few against it. It is futile to argue that the climate today is not under the same controls that have regulated it for thousands of years...."
Dyson and his colleagues predicted global cooling but also observed the alleged indicator: the previous 100 years of shrinking glaciers, warming of Arctic, rising snowlines, noticeable warming in temperate and Arctic regions, and rising sea level.