To the Editor:

Peter Shaw’s article, “Apocalypse Again” [April], omits two very important considerations in the tenacious and tendentious propagation of predictions of imminent catastrophe. Researchers in the environmental sciences are in incessant need of generating funds, usually public funds, for professional survival and they accumulate enormous intellectual and emotional baggage. Having been involved in such pursuits (mainly at NASA) for over thirty years, I know the stakes and the temptations coincident with scientific research.

Just to cite one example: for a number of years I was closely associated with most of the authors of the famous (or to some people infamous) TTAPS “nuclear-winter” paper (so-called after its authors, Turco, Toon, Ackerman, Pollack, and Sagan) and indeed published a number of papers with them. Several of the papers were on the atmospheric model which lay at the heart of the TTAPS study. It simply turned out that while the model was quite adequate for studying some of the physics and chemistry of the particles formed by a volcanic eruption, it was far too simple for predicting “nuclear-winter” effects. So it is with all of the atmospheric models generated so far, including the model used by Jim Hansen, the principal prophet of doom regarding the “greenhouse effect.” Moreover, it is most unlikely that an adequate model for studying the effect will ever be developed. Knowledge of this improbability stems from a new branch of physics frequently called “chaos theory.” . . . Despite its questionable nature, the “greenhouse theory” is even now a potent source of funding for researchers, and many of them have developed an enormous professional and emotional stake in its public acceptance. A hungry and utopia-oriented scientist should not be underestimated! . . .

Robert C. Whitten
Cupertino, California

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To the Editor:

Peter Shaw writes of “the mistaken assumption that forests worldwide are decreasing in size (they are not).” I would like to know how Mr. Shaw justifies this, what I consider, amazing statement.

Harold Enten
Bronx, New Yorx

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Peter Shaw writes:

Robert C. Whitten’s example of how the limitations of science can combine with the self-interested and/or altruistic motives of scientists fills in a part of the puzzle of why we are increasingly subject to irresponsible apocalypticism.

In reply to Harold Enten, my source for the statement about world forestation is “Global Forests,” a survey of world forest studies by Roger A. Sedjo and Marion Clawson printed in Julian L. Simon and Herman Kahn’s The Resourceful Earth (1984). Sedjo and Clawson conclude that “there is certainly nothing in the data to suggest that the world is experiencing significant net deforestation.”

Estimates of how much forest there is in the world vary from approximately 2½ million to approximately 6 million hectares. We do not know either how much forest exists or by how much it may be increasing or decreasing. The best guess seems to be that forests in the industrialized countries, despite all the hoopla over acid rain, are either stable or increasing, and that “while serious local problems of excessive deforestation do exist in some regions of the tropics,” the net loss has been much exaggerated.

Efforts to prevent loss of forest acreage in the Amazon and elsewhere are to be commended. Apocalyptic exaggerations of how the loss affects the global forest balance are not—unless you believe in lying to support a good cause.

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