Nuclear War: Will starve
1987/08/01 Tolaretxipi, E. Iturria: Elhuyar aldizkaria
Talking about nuclear winter is not fantasy. According to a comprehensive study by the Scientific Committee on Environmental Problems (SCOPE), nuclear winter is the largest expected climate change. For these authors, much smaller changes, such as decreasing certain degrees of temperature, can have tremendous consequences on world food production, especially if it occurs at a particular time of growth.
The direct effects of nuclear weapons (wind gusts, thermal pulse and radiation) are known both by the tests and by the two explosions carried out in Japan. Indirect effects have focused on this last five years. Several studies have analyzed the nuclear events and winters that would mean an explosion of about 5000 megatons.
Suppose the thermal pulse of a nuclear explosion causes cities and forests to burn. Fires throw huge amounts of smoke into the atmosphere. This smoke falls in the form of black rain or stays in the atmosphere destroying sunlight and preventing it from reaching Earth. The atmospheric temperature is completely changing the overall circulation pattern. The temperature of the Earth in summer drops to 20-30ºC in the center of the continent.
SCOPE research confirms the same. According to him, the explosion of 5000 megatons, half the power of the world's weapons, would drastically reduce the level of light in the north hermission. The temperature would decrease in a few days on the continents. Rain cycles would have a variation of one month or more.
This study also shows that if explosive megatons only shot a hundred in large cities, twenty percent of the advanced world would become dust. This would mean the generation of 80 million tons of fumes, of which 45 million would be pure carbon, the best shock absorber of sunlight.
The smoke that causes burning oil and coal deposits and asphalt in cities is even more important (according to the study). Fossil fuels and their derived materials, such as asphalt and plastic, generate large amounts of black soot. Wood does not generate so many problems.
The cities of the southern hemisphere will not be totally isolated from the nuclear war of the northern hemisphere. If the smoke is emitted into the atmosphere between April and September, the sun warms the smoke-laden air and propels it into the stratosphere in the form of waves. Thus, normal patterns of atmospheric circulation will not be able to return to the ground. On the contrary, the smoke will pass to the equator. Within a few weeks the thin layer of smoke can be extended to the latitudes of the southern hemisphere. But here it will be winter and therefore the temperature will not decrease in many degrees.
Fixing the smoke in the stratosphere will prevent rain falling. According to SCOPE, it will continue for a year or more, cooling the soil temperature a few degrees. Global rainfall systems will change drastically and torrential summer rains in Asia and Africa would decrease considerably.
The most recent and significant conclusions of the SCOPE study refer to the agrarian and biological effects. Major global agricultural systems are soon experiencing climate change.
Climate change has a great influence on the world's large agricultural systems. This means that the concrete details of a nuclear explosion may not be as important as people believe; a "small" nuclear war is enough to change the climate and cause great damage to agriculture.
According to the SCOPE study, a decrease in temperature from 3 to 5°C during breeding would destroy crops in North America and the Soviet Union. Japanese rice production would also suffer great damage.
According to the SCOPE, the nations at greatest risk, those in energy and food dependence and those with little energy and food for their population. SCOPE's message is that, in this case, non-participating nations will be the most affected.
This study has also taken into account the effect of pollutants on the atmosphere after the nuclear war. The ozone concentration could drop from 10% to 30% in a month and we would need a few years to refill it.
Burning wood and fossil fuels would cause the emission of large amounts of toxic substances into the lower atmosphere. Chemical and petrochemical plants have special relevance.
In the last decade there seems to be changes in the arsenals of the world superpowers. Despite this change, the scope forecast is: 7% of the territories of the United States, the Soviet Union and Europe will receive gamma rays of nuclear rain in 48 hours. According to the study, a large pump exchange would take the population to an average dose of gamma rays in the northern hemisphere of about 10 rad. This is 100 times the previous level.
As a source of global nuclear rain, the SCOPE mentions nuclear facilities. In view of all this, the doubts arising from both parties remain unresolved. On the one hand, nobody knows how that human behavior will be; how many weapons will be used, etc. On the other hand, the knowledge of physical processes is also not absolute; how far the smoke will rise, the characteristics of the great fires, etc.