Murray Mitchell, head climatologist at the Government’s Environmental Sciences Services Administration, reported recently that the average world temperature has fallen about one-third of a degree centigrade since 1950.
At that rate, he says, it would take only 240 years to return the earth to an “ice age climate.”
Dr Mitchell and other “climatologists” say they expect to see ice floes continuing to close in around Iceland, glaciers will grow in the Pacific north-west of the United States, and there will be major changes in farming patterns.
An “ice age climate” means simply that more snow falls in the winter than melts in the summer. At the present rate, of course, it would take 1,000 years to reach the point where glaciers and ice floes really began taking over. And a warming could reverse the process. But experts agree that the general trend has been toward a cooler earth for the past 6,000 years.
Nobody quite agrees on the reasons for this, especially the marked movement of the past decade.
Dr Mitchell thinks that the earth’s volcanic activity, which has been slightly on the increase since 1940, has thrown up enough dust into the atmosphere to cut out the sun’s warming rays. This, he says, has caused the cooling trend.
But Professor Reid A. Bryson of the University of Wisconsin is among those who believe that the cooling trend results from a different kind of atmospheric pollution, man-made. He is convinced that the exhaust fumes from automobiles and jet aircraft, the belching of smoke from coal furnaces, the putrid cinders from open-pit garbage and trash burning, has polluted the atmosphere enough to cut off radiation from the sun and thus lowering the amount of heat the earth receives from the sun.
Those who share this view, and there is a growing number, fear that there will be little life left on the earth by the time such an “ice age climate” takes over. In fact this is a fear that has fairly gripped a good number of Americans lately, particularly the youth.
The whole question of the earth’s physical survival has become the cause celebre of those who last year were rioting on campuses and demanding a radicalisation of university and national political life. Air and water pollution, land usage, insecticides, herbicides, thermal pollution, strip-mining, trash disposal, animal and forest conservation — these have suddenly become the overriding concerns of a generation of Americans who until as recently as six months ago were chanting anti-war slogans.
The war in Vietnam has no longer the ring of concern in it that the war on blight and pollution has. Even the war on poverty has taken a back seat. This partially accounts for the silence on college campuses this year.
The trend was evident last September. At one large university in the western United States, a course in “man and his environment” was offered. The registrar expected perhaps a maximum of 400 to sign up. In fact more than 2,000 enrolled in the course. Today even more would sign up.
Source: The Canberra Times