‘Nuclear Winter’ Seen Killing More Than Atomic Blasts : After U.S.-Soviet War, Famine Would Peril Entire Population of World, Scientists Say

In the most detailed public study yet of “nuclear winter,” an international team of scientists theorized Thursday that a U.S.-Soviet nuclear war would result in a worldwide famine that could kill billions--far more than even the casualties of the initial blasts, fires and radiation.

In announcing the findings of nearly three years of research, the team of 300 experts said that the clouds of soot that would fill the skies after major American and Soviet industrial complexes were destroyed in nuclear attacks could wipe out a year of growth in some of the world’s major grain regions.

“We are left with the (starvation) image of Ethiopia and the Sudan as being more representative of what the world would look like after a nuclear war . . . (rather) than the sorts of images we have of Hiroshima and Nagasaki,” Mark A. Harwell, associate director of Cornell University’s Ecosystems Research Center and a member of the team, said at a news conference.

Long-Term Problem

The two-volume, 859-page report builds on several earlier studies that looked beyond the damage that would be wreaked on targets of nuclear warheads. Those studies had already pointed out the potential long-term problem of “nuclear winter”--the lowering of temperatures as the soot of industrial and urban fires obliterated the sun.

For example, a recent report prepared by a private consulting company for the Pentagon’s Defense Nuclear Agency drew attention to “far more extensive” requirements for caring for nuclear war survivors than current civil defense plans envision.

The new study, which like previous ones assumes that nuclear warheads would hit cities and fuel depots rather than missile silos in isolated regions, warned:

“The indirect effects on populations of a large-scale nuclear war--particularly the climatic effects caused by smoke--could be potentially more consequential globally than the direct effects, and the risks of unprecedented consequences are great for noncombatant and combatant countries alike.”

Deaths in Hundred Millions

Harwell estimated that, although several hundred million persons could die as a result of the direct effects of a nuclear war, “the indirect effect potentially could lead to deaths in the range of 1 to 4 billion”--a number approaching the estimated global population of 4.6 billion.

He noted, for example, that more people would die in India--as a result of the disruption of the seasonal monsoon rains, on which the subcontinent’s agriculture is dependent--than in the United States and the Soviet Union combined if the superpowers fired their nuclear arsenals at each other.

“The main mechanism by which people would die would not be the blast effect, would not be burns, would not be radiation, but rather would be mass starvation,” Harwell said.

He added: “These conclusions do not represent the views of political activists or environmental extremists or people with any particular policy position. But, rather, we feel this is a sober assessment . . . on agriculture and ecological systems.”

10 Nations Visited

The research team, which drew on visits to 10 nations and on the work of scientists from 30 countries, was directed by Sir Frederick Warner, a chemical engineer who has served as chairman of the British National Committee on Problems of the Environment, and a team assembled by the International Council of Scientific Unions. The council is a nonprofit organization composed of representatives from 70 national academies of science and representatives of other groups.

The researchers predicted that, after a nuclear exchange, smoke plumes would rise 10 to 20 miles above the Earth, higher than previously thought, at a speed of 180 m.p.h. and would quickly produce a sharp drop in temperature.

In studying individual crops around the world, the degree to which regional populations depend on them, the impact that minor and major shifts in climate can have on them and disruptions on food imports and exports, the report found that some agricultural products would be eliminated--even if they were growing in a different global hemisphere from the site of the war.

Radiation ‘Hot Spots’

In addition, it said, radiation “hot spots” and lack of fuel would contribute to the crop failures.

“During the acute period of a significant nuclear war-caused climatic event, rice production would be essentially eliminated in at least the northern hemisphere, and the southern hemisphere could experience the same fate,” the report said.

According to the U.S. Department of Agriculture, nearly 2 billion people depend on rice for more than 80% of their diet, and “a moderately serious weather problem in just a few countries can cause significant shocks in production.”

The researchers based their work on computer models, drawing on such data as food production and consumption, climatic conditions and the responses of individual species of plants to shifts in weather.

In the United States, the report said, average daily temperatures could fall about 35 degrees during the first few weeks after a nuclear war and precipitation could temporarily drop 100%.

“Climatic stresses of half this magnitude could essentially eliminate an entire growing season of production,” it found.