Washington — I have put in a good deal of time lately worrying about the polar ice-caps. It started in a crowded Senate committee chamber the other day when energetic Sen. Paul Tsongas (D) of Massachusetts took testimony from a galaxy of natural scientists talking about the buildup of carbon dioxide (CO in Earth's atmosphere. The rate the stuff is increasing, what with revived consumption of coal, is likely to change the Earth's climate.
Coal liberates CO, you see, and creates the so-called "greenhouse effect." That means that more warmth will stay inside the Earth's atmospheric shield and the world will become warmer. So what happens in the Arctic and the Antartic? There incredible amounts of water are frozen into the ice sheets. Warm the ocean's temperature a few degrees and the ice begins to melt and the level of the ocean begins to rise. In no time at all (half a century or so perhaps) the sea has gone over its banks, the lower parts of Louisiana are under water, Holland is submerged, and for all I know they will be fishing out of the second floor window of the Chrysler building.
The layman rubs his eyes. These experts are not smiling; they are serious. It is no bizarre science fiction to them. They talk familiarly of the last ice age (just yesterday, as it seems) and the possible correlation of sun spots and glaciation. They talk as though humanity were on a perilous course and they quote a July, 1979, report submitted by four internationally respected scientists that begins:
"Man is setting in motion a series of events that seem certain to cause a significant warming of the world climates over the next decades unless mitigating steps are taken immediately."
The spectator gropes for a time-frame; are they talking about a million years or tomorrow? They are talking about the middle half of the next century and, more particularly, of here and now, and the increased liberation of carbon-dioxide gas that has already begun. It could have effects on the world of our grandchildren in various disagreeable ways, like "acid rain," or the inundation of coastal cities.
To much carbon dioxide in the atmosphere, it seems produces a warmer climate. In the past the Earth's forests have absorbed an extraordinary amount of the carbon, but half of the world's forests, according to testimony, have disappeared in the past 30 years. So there is a one-two action: more CO from burning fossil fuels, and less natural absorption of it from diminution of the global forests.
They have been measuring the rise of carbon dioxide at, of all places, Mauna Loa, where laboratories have worked since 1958. Here is what George M. Woodwell , director of the Ecosystems Center at Woods Hole, Massachusetts, told the Senate committee April 3. The carbon content of the atmosphere has been rising and now seems to be rising faster. The range may be in the nature "of 500-600 parts per million sometime in the first half of the next century." What does that mean?
"Such an increase is important because it is expected to raise the average temperature of the Earth two or three degrees centigrade."
The listener asks if that is so bad after all? The grim ecologist says that the presumed warning will be "differential"; that is, the poles will be warmed more than the tropics. "There is a possibility that the melting of the polar ice, especially the West Antarctic ice cap, will occur in a relatively short time and will be sufficient to raise the sea level by as much as 20 feet over the course of a century or two -- perhaps suddenly as large segments of the ice cap slip into the sea."
For a newspaper reporter who has been out watching the presidential candidates, this is all very unusual. What is the appropriate response? At first there is the temptation of levity: "Uh-huh, there goes Martha's Vineyard!" -- or something like that. But that response is because the possibilities are so staggering. There is nothing humorous in this presentation of man's best current knowledge of possible trouble ahead -- unless some alternate energy source is harnessed to replace fossil fuel. Says Dr. Woodwell quitely:
"Mostly scientists agree that man is on the verge of making large and substantially irreversible changes in the biosphere as a whole . . . and that these changes will not be to his advantage."