March 1990 (vol. 6, #3) 1601 N. Tucson Blvd. Suite 9, Tucson AZ 85716 c 1990 J Orient

Socially responsible physicians have had little to say about possible causes for the thaw in the cold war. They can hardly claim credit, for the Peace Center's program has not been enacted. We have not had a freeze, a comprehensive test ban, or a new arms control agreement. Not a single nuclear weapon has been destroyed.

On the other hand, the peace activists' methods are widely used, though perhaps not exactly as intended: protesters carry signs (e.g. ``Freiheit statt Sozialismus'' Freedom, Not Socialism) and trespass on government property (e.g. East Germans seizing files from the headquarters of Stasi, the secret police). It may be that peace activists have no time for reflection or celebration. Immediate mobilization is needed to prevent the imminent destruction of the global environment, if not by war, then by another, equally dreadful threat. Or it may be that the events in Eastern Europe are simply irrelevant, the Soviet Union never having been perceived as a nuclear threat. (After all, protests continue at the Nevada Test Site.)

The new threat is fundamentally different from most medical problems that affect individuals. In the case of the latter, physicians are urged (if not mandated) to avoid treatments that have not been proved effective, or cost-effective, in extensive clinical trials.

``Can we put action on the back burner while we wait and see?'' queries Dr. Alexander Leaf<sup>,1</sup> of Physicians for Social Responsibility. Clearly not the effects of environmental change are ``analogous to those of nuclear war.''

Predictions made by Dr. Leaf include: (1) A 6-meter rise in sea levels due to the melting of the polar icecaps; (2) starvation due to flooding, drought, and possibly a CO₂-induced inhibition of plant growth; (3) deaths due to heat stroke, especially if the use of air conditioning is curtailed; (4) epidemics caused by contaminated water, proliferating insect vectors, immune suppression by ultraviolet-B radiation, and the migration of unimmunized persons; (5) cataracts, cancer, and more. Except for the nature of the climatic catastrophe, the list bears a striking resemblance to the effects of the previous ``last epidemic.''

Confirming the Diagnosis

Before searching for the etiology of a cancer, the first step is to confirm the existence of cancer. Although atmospheric CO₂ has increased, the alleged rise in global temperature is not established. A compilation of 60 million shipboard measurements of sea surface temperature since 1860 shows an increase of 0.2 C over 120 years. This is within the estimated margin of error and compatible with the possibility that there has been no global warming trend at all in the last century.²

Even if there has been an increase in temperature, a correlation does not establish a cause-effect relationship. Climatic variations can result from natural factors, such as volcanic activity and changes in solar energy output.³

As to the consequences of global warming, doomsday forecasts generally disregard the natural feedback mechanisms that are triggered by changes in temperature. These mechanisms include ocean currents, clouds, and the activities of living organisms. For example, a warmer polar climate may increase precipitation, offsetting the tendency for icecap melting. As demonstrated by Geosat radar altimetry, the thickness of the Greenland ice sheet is actually increasing, contrary to Dr. Leaf's prediction.^4,5

Assessing the Treatment

The ``Heat Is On'' crusade spearheaded by the Union of Concerned Scientists (UCS) calls for drastic changes in energy policy. To stabilize the atmospheric concentration of CO₂ at current levels would require a 50 to 80% reduction in industrial emissions to be achieved without utilizing the only feasible method of electric power production that generates no CO₂ [nuclear]. The price tag: annual expenditures approaching $150 billion by 2000.¹ The source of the funds: defense.¹

This draconian and unproved ``solution'' to a possibly nonexistent problem has many potential side effects. It would undoubtedly cause serious damage to American industry and living standards. It could also harm the intended beneficiary, the planet earth. A warming trend might actually be needed to ameliorate natural cooling that could lead to a new ice age.³ And increases in CO2 appear to be extremely beneficial to living organisms (see p. 2)^.6

Side effects and lack of efficacy might be absolute contraindications to radical therapy for a simple rise in CO₂ levels. But the ultimate concern is Dr. Leaf's etiologic diagnosis: ``personal and national greed'' (i.e. the strength and prosperity of the US). The agenda of the peace movement thus remains the same: disarmament of the US, with or without a treaty.

SELECTED REFERENCES (additional information available on request)

1. Leaf A: Potential health effects of global climatic and environmental changes. N Engl J Med 321:1577-1583, 1989.

2. Has the globe really warmed? Technology Review Nov/Dec 89, p. 80.

3. George C. Marshall Institute: Scientific Perspectives on the Greenhouse Problem, 1989.

4. Zwally HJ et al.: Growth of Greenland ice sheet: measurement. Science 246:1587-1589, 1989.

5. Zwally HJ: Growth of Greenland ice sheet: interpretation. Science 246:1589-1591, 1989.

6. Idso SB: Carbon Dioxide and Global Change: Earth in Transition. IBR, 631 E. Laguna Drive, Tempe AZ 1989 (over 2000 references).