Some scientists are convinced that the world's climate is getting colder every year, threatening a return to the conditions of the last ice age, which reached its peak about 18,000 years ago.
From 1890 to 1940 worldwide temperatures rose about 0.18F every 10 years. Some animals extended their ranges northward, the sea was less frozen than before, and icebergs from Greenland did not penetrate as far south.
Since 1940 temperature has been dropping. According to a survey by the National Oceanic and Atmospheric Administration, the average ground readings for the northern hemisphere have, in the years from 1945 to 1968, fallen by one-half degree F. In the United States, east of the Continenal Divide, temperatures in the last decade averaged one to four degrees cooler than in the past 30 years.
---page 69. Strange Stories, Amazing Facts
Published 1976, The Readers Digest Association
Library of Congress Catalog Card No. 76-2966
[The notion that cooling is being helped by man appears only in the subtitle of the article. Nothing in the article suggests how man might be accomplishing planetary cooling.]