APPENDIX

STATEMENT SUBMITTED BY JOANNE SIMPSON, PH. D., PROFESSOR OF ENVIRONMENTAL SCIENCES, UNIVERSITY OF VIRGINIA, CHARLOTTESVILLE, VA.

The atmosphere recognizes no national boundaries. The deepening of a storm in the Gulf of Alaska can affect the weather over England, by altering the large wind systems that meander in a jet at altitudes of 8 miles or so above the earth. Weather modification is in its infancy and holds vast immediate potential to benefit man. As a weapon, it is unlikely to be cost-effective in the foreseeable future. Weather forecasting, on the other hand, is in its adolescence. Accurate forecasts are vital to the human life and economy of all nations. The rapid strides in weather prediction, its very continuation, are crucially dependent upon the cooperation of all nations, particularly in supplying weather observations to be fed into computers to process the advanced prediction models now in use and those to come.

In World War II, when I was trained in meteorology, we were taught, as part of the war-time emergency, to forecast the weather as best we could using only the observations at our own station, assuming that the enemy had blocked out distant weather observations or their communication to us. This was called "single station" forecasting, and at best, it was not very good. Refusal to take and transmit weather data is a powerful weapon of warfare, far more damaging to an enemy than any weather modification technique that I can envisage may become usable in my lifetime.

International cooperation is the lifeblood of meteorology, both in operations, modification and in the research that is vitally necessary to make these applications successful. Meteorologists of all nations have had both a necessity and a tradition of close collaboration and completely free exchange of data, of ideas, and of technology. Continuation of this cooperation and exchange is in the best interests of the United States and of every other nation in the world.

I chose meteorology as a profession in large part because of its international nature, because by helping develop atmospheric science I could serve my country, not only by learning how to modify our clouds and precipitation but also by playing a small role in cementing international communications and exchanges which are so vital if peace is to be maintained.

That is the double reason I am so pleased to be here today. I believe the greatest contribution that I could make from the 32 years I have devoted to atmospheric science would be to help in any way, however small, to bring about an international resolution aimed at using the atmosphere and oceans for peaceful purposes only. This specifically implies an agreement upon the part of all the nations involved not to use weather, climate and/or ocean modification as a weapon of warfare. In my opinion, to concur to and to keep this agreement would give rise to a very large benefit to the United States and little if any loss, even to the military arsenal which is already replete with deadly weapons. On the other hand, failing to make or to keep such an agreement will surely lead to irreparable harm to the interests of the United States.

I have stronger and better reasons to back this statement than some of the bugbears raised by a few of my fellow scientists. I do not particularly dread possible harmful "side effects" of weather modification. Although there could possibly be some, their effects on weather are likely to be small compared to natural oscillations in flood and drought, storm tracks and wind patterns. Some degree of direct "poisoning" of the atmosphere, earth, or water bodies is also possible, but is not likely to be comparable to the pollutants introduced by peacetime living, industry, jet aircraft and automobiles.

Nor do I fear that some Dr. Strangelove in an enemy nation is going to invent a machine to steer hurricanes, hurl tornadoes at us, dry up our crops with drought, or inundate our cities with floods. This sort of science fiction often appears in the Sunday supplements, but belongs more properly in the comic pages. The atmosphere is infinitely more powerful than man and infinitely harder to modify than almost everyone, including many meteorologists, believe. Just for one example, an ordinary run-of-the-mill mature hurricane releases as much condensation heat energy through its cloud systems in one day as the nuclear fusion energy of about 400 20 megaton hydrogen bombs. Some people have been naive enough to suggest trying to dissipate a hurricane by dropping a hydrogen bomb in it! The intensity and track of a hurricane often varies more in a day all on its own, than any change man might desire to try.

Hard facts on weather modification are needed for your group to make a decision. What is the actual status of weather modification today? Could any weather modification technique now or foreseeably be used cost-effectively in warfare and if so, what would be the price of actual or developmental use of it? When I say price I do not mean just cost in dollars, but the negative contribution as a whole, to the national interest.

A paramount hard fact about weather modification is that there are today only about a half-dozen programs over the whole world that have conclusively demonstrated that the treatment works. These programs nearly all involve cloud seeding with silver iodide, or a similar chemical, to increase precipitation. Three types of cloud situation have been demonstrated amenable to precipitation increase by seeding, when the right circumstances are very carefully selected by theory, measurement and computer model. Years of research and unsuccessful experimentation preceded the successful experiments. The treatable cloud conditions to date are as follows: First, certain orographic cloud systems, particularly in the mountainous regions of the western United States and in Australia. Second, some winter cyclonic storm systems, particularly in Israel, and the west coast of the United States. In both these situations, economically useful average precipitation increases of about 10-50% have been established. The third cloud situation consists of isolated tropical cumulus clouds, where a different principle of silver iodide seeding is involved. This is called "dynamic seeding" because under the right conditions the cloud growth is increased and prolonged. Development of this approach has been the aspect of weather modification to which I personally have contributed, particularly during my government employment in NOAA, the National Oceanic and Atmospheric Administration of the Department of Commerce. With isolated tropical cranulus clouds, we have shown that, under the right conditions, the precipitation from an individual cloud can be increased by a factor of about 2 or 3, that is to say, doubled or tripled. Whether or not dynamic seeding can be used economically to increase the precipitation over a sizeable area is still in the early stages of investigation and is unlikely to be established before 3 to 5 years from now at best

All these modification techniques require not only pre-existing clouds, but also that some portions of these clouds must contain droplets which are cocled below the freezing temperature (namel supercooled) for silver iodide to work. In increasing precipitation by other techniques than silver iodide, which might work on clouds not large enough to be supercooled, some progress has been made in accelerating or increasing precipitation by means of hygroscopic substances such as common salt or the fertilizer urea. These methods are still in the experimental stage, although encouraging progress is reported in the Dakotas program. At present, and in the foreseeable future, there is no reliable method to create sizeable clouds out of a clear sky, except under rare conditions, or with great expenditure and/or when nature is on the verge of making a cloud anyway.

Increasing precipitation by 10-20% over a whole area over an entire season is thus possible under restricted conditions, but causing deliberate precipitation on a limited target at a strategically desired time is a horse of a very different color. On rare occasions, targetting may be successfully achieved, when suitable clouds just happen to be found over or upwind of the chosen spot. For example, in south Florida, we have managed to get a seeded cloud over a 200 sq. mile instrumented target on roughly about 10% of the occasions when seedable clouds were found over a 5000 sq. mile seeding target. Since seedable clouds are available over south Florida on roughly 30% of summer days, this means that one or more clouds might be targetted there onto a chosen 5% of the area about 3% of the time. This figure may be typical for flat land areas in tropical air masses. Near mountains or islands, targetting might be more or less difficult, depending on how the preferred locations for cloud growth relate to the target and to the prevailing air flow. This whole subject is just now becoming amenable to productive research and experimentation.

So far, in this testimony, I have attempted to assess for you that aspect of weather modification related to precipitation increases from existing clouds. Clearly, in the present state of knowledge and development, this aspect is unlikely to be a cost-effective weapon, though an enemy in some places could be inconvenienced on a small fraction of sorties. The employment of rain-making as a weapon, however, would in my opinion be much worse than a waste of resources, because of the damage to international cooperation in meteorology. I will return to that most important aspect in my conclusion.

Let us continue now with the hard facts about scientific feasibility. What about decreasing precipitation? This is a frontier for research and development, some of which is underway in the Soviet Union. I am unaware of any demonstrated results of properly controlled experiments, nor of any applications even claimed to be successful.

The next topic of major concern, on which real progress has been made, is in the modification of severe storms, in particular lightning, hail and the tropical hurricane. Tornadoes are still in the research phase and have not reached the stage of field modification experiments, nor even good theories or models upon which to base them.

Lightning suppression is in the controlled field experiment stage and appears promising. Hurricane experimentation has been intermittently underway by the United States beginning in 1947 and more seriously and knowledgeably since 1961. The project is a United States Government program called Stormfury. Its design is to determine whether storm winds can be reduced in intensity. There is no intention to and no good ideas how either to steer or to dissipate these storms, despite some media reports to the contrary. The Stormfury experiments are in their infancy. Either many years of effort or hugely increased resources will be necessary to pin down the feasibility of this one aspect of hurricane modification. No experiments have been attempted on incipient or developing storms, for reasons too long to cite here.

In hail suppression, the Soviet Union leads the world, although their claims of 70-90% reduction in damage and benefit-to-cost ratios of ten or more are not fully accepted in our scientific community. The reason is that their experiments, although backed by fine instrumentation and extensive theory, have not been double-blind. In the United States, a similar program, the National Hail Research Experiment, is underway in Colorado with the proper statistical controls. It began in 1972 and it is not expected that suppression results of just one method of treatment can be definitely evaluated prior to 1977. Concerning hail instigation or augmentation, various madcap schemes nave been suggested, but to my knowledge none have been backed by res arch or tested in the field.

The final aspect of weather modification I shall address is fog. I am unfamiliar with any successful efforts to create fogs, although it would seem a possible area of investigation under calm conditions when nature was close to fog production anyhow. On the other hand, the dispersal of cold or supercooled fogs has long ago been demonstrated successful in calm or light winds and has been in economic operation at more than a dozen airfields over the world for many years. With warm fogs, significant progress has been made on their dissipation by helicopter downwash, the heat from burners, or, by seeding with hygroscopic substances.

Much of the work on fog dispersal has been developed and used by the United States military services. Whether or not the dispersal of a fog at an airport landing military aircraft (carrying bombs or wounded persons) constitutes a use of weather modification for warfare I will leave to the people, their representatives in Congress and on international bodies, and their lawyers, to decide and negotiate with their counterparts in other nations.

My strong recommendation is that it is in the national interest to lean more on the side of eliminating marginal uses of weather modification at some short-range cost than to slide in the other direction. This leads me to my conclusion.

In conclusion, this country and the world face food and energy shortages. Beneficial use of the atmosphere, which must be based on international cooperation, with free exchange of data and information, could make a major, even crucial difference in our economy and in the livelihoods of multitudes. Much more is at stake than the deliberate modification of the atmosphere, potentially valuable as that surely is. Weather prediction is at stake, air and water quality, the extraction of some forms of energy and many aspects of agriculture and fisheries. Hostile use, or attempts at hostile use, of weather modification would inevitably undermine that international cooperation which is mandatory to predict, conserve and manage man's environment on this planet.

The International Global Atmospheric Research Program's Tropical Atlantic Experiment (GATE) is now going on in and above the Atlantic Ocean west of Africa. More than six nations are pooling talent, expertise and expensive facilities to surmount the key roadblocks in global weather prediction and related problems involving the air-sea interface and cloud and storm systems. The fragile basis of these cooperative efforts is painfully clear to me. This special pooling of resources and also their routine, day-to-day pooling in global weather networks are essentials for civilization that could readily be jeopardized. Major jeopardy would threaten if one or more powerful nations began to use or condone weather modification as a weapon. Is any person going freely to contribute to a neighborhood project to build a machine if he thinks one of his neighbors may use the machine to harm or to kill him?

For this priceless benefit of environmental cooperation, a price is exacted. But the price is fortunately low. We must renounce use of the current state of weather modification for warfare. Today, most aspects of weather modification are promising for peaceful use but do not provide cost-effective weapons. The avoidance of those few techniques which might be cost-effective as weapons, such as fog dispersal, constitutes a loss incomparably less harmful to our national interest than would be the loss incurred by adopting the opposite alternative.

For the future of weather modification, the national interest, backed by the hardest facts and soundest science available, dictates that we dedicate our developmental resources into open, unclassified scientific and technological programs for which the foreseeable and intended application is the peaceful betterment of man and his environment. This dedication is not just noble and desirable, but in fact is coldly and practically necessary, because the atmosphere covers the whole planet in its complex turbulent motions; its nature and problems are global. To understand, predict and control it is so difficult, that only by pooling resources, by international cooperation can man improve his life on this earth, or perhaps even maintain his very existence.

"WEATHER WARFARE: EFFORT", ARTICLE

PENTAGON CONCEDES 7-YEAR VIETNAM BY DEBORAH SHAPLEY, FROM SCIENCE

MAGAZINE, VOL. 184, JUNE 7, 1974

On 20 March, several high-ranking officials of the Department of Defense (DOD) told members of the Senate Foreign Relations Committee in detail about a $21.6 million 7-year program of cloud-seeding to induce rain over the trails of Laos, North Vietnam, South Vietnam, and Cambodia. There had been persistent allegations that the military was carrying out such operations in Southeast Asia. Their briefing, therefore, constitutes the first public description of weather modification techniques as a weapon of war.* Senator Claiborne Pell (D-R.I.), who asked for the briefing, recently released the text of it, of which excerpts follow. The use of rainmaking as a weapon of war has long been a subject of controversy among weather scientists and armis control experts. Some of the scientists have objected that military use of weather modification will inhibit international cooperation in the atmospheric science. Their work, they add, should be used for humanitarian ends such as increasing the world's food supply. Some arms control experts fear that weather modification indiscriminately hurts noncombatants and enemy troops; they also argue tha (U.S. use of it in Vietnam could lead to proliferation of this relatively simple weapon to other countries (Science, 16 June 1972). In any event, the Pentagon's briefing to Pell is far and away the most complete statement DOD has made to date of its role in weather warfare. [Even former DOD Secretary Melvin Laird hedged on the issue (Science, 5 April).] While it furnishes many new details, some other information is still missing. For example, there is only vague discussion of whether agencies other than DOD have engaged or are engaging in weather warfare-yet the Central Intelligence Agency (CIA) is alleged to have started Vietnam cloud-seeding with a rainmaking project over Saigon in 1963. There is some discussion of an ongoing National Security Council review of weather modification policies, but no statement of DOD's position on future military weather modification programs. Finally, the military's claim that they succeeded in inducing from 1 to 7 inches of rain in Southeast Asia is not supported with the kind of data that civilian scientists would need for verifying it. Hence the DOD's claim that weather modification is "a valuable tactical weapon" is not proven.

Most of the presentation was made by Lieutenant Colonel Ed Soyster of the Joint Chiefs of Staff. Other DOD spokesmen were: Dennis J. Doolin, Deputy Assistant Secretary of Defense (East Asia and Pacific Affairs); Major General Ray Furlong, Deputy Assistant Secretary of Defense (Legislative Affairs).

Soyster began by describing the regular Southeast Asian monsoon seasons. He explained that the southwest monsoon begins with a transitional period from April to June and ends with a similar period in September. During these transitional times, unpaved roads in Southeast Asia can sometimes become impassable due to sudden rains or floods: during the monsoon itself such roads are muddy all the time.

The program was to increase rainfall sufficiently in carefully selected target areas to further soften the road surfaces, cause landslides along roadways, and to wash out river crossings. These events normally *** occur anyway during the height of the rainy season. By seeding it was intended to extend the period of occurrence beyond the normal rainy season and to supplement the natural rainfall as required to maintain the resultant poor traffic conditions.

He then described some principles of tropical cumulus cloud growth and development, and how, in general, cloud-seeding works. As to the specific technique DOD cloud-seeders used:

The seeding units used to seed were developed at the Naval Weapons Center, China Lake, Calif. and are not classified. The seeding units and technique are identical to those used in publicized rainmaking projects-for example, Philippines, Okinawa, Texas-and the Stormfury research project.

Weather Modification, hearings before the Subcommittee on Oceans and International Environment, Committee on Foreign Relations, U.S. Senate (Government Printing Office, Washington, D.C., 1974).