Nuclear Winter

By: Jack, Casey, and Rachel

Nuclear Winter

Nuclear winter (also known as atomic winter) is a hypothetical climatic effect, most often considered a potential threat following a countervalue or city-targeted, Nuclear War.

The Cold War

In the 1980's, work conducted jointly by Western and Soviet scientists showed that for a full-scale nuclear war between the United States and the Soviet Union the climatic consequences, and indirect effects of the collapse of society, would be so severe that the ensuing nuclear winter would produce famine for billions of people far from the target zones.

Some Possible Images

In 1990, in a paper entitled "Climate and Smoke: An Appraisal of Nuclear Winter," TTAPS give a more detailed description of the short- and long-term atmospheric effects of a nuclear war using a three-dimensional model.

First 1 to 3 months:

  • 10 to 25% of soot injected is immediately removed by precipitation, while the rest is transported over the globe in 1 to 2 weeks

  • SCOPE figures for July smoke injection:

    • 72 °F drop in mid-latitudes

    • 50 °F drop in humid climates

    • 75% decrease in rainfall in mid-latitudes

    • Light level reduction of 0% in low latitudes to 90% in high smoke injection areas

  • SCOPE figures for winter smoke injection:

    • Temperature drops between 38 and 39 °F

Following 1 to 3 years:

  • 25 to 40% of injected smoke is stabilised in atmosphere (NCAR). Smoke stabilised for approximately 1 year.

  • Land temperatures of several degrees below normal

  • Ocean surface temperature between 36 and 43 °F

  • Ozone depletion of 50% leading to 200% increase in UV radiation incident on surface.

The Outcome

In 1983, a conference on the issue of a nuclear war was organised by American scientists. The conference was titled ‘The Long-Term Worldwide Consequences of Nuclear War’. It concluded that a nuclear war would involve the use of 5,000 megatons of nuclear bombs. These bombs would produce 225 million tons of smoke alone. The darkness created by these explosions would last for weeks and even months. Without the rays of the Sun penetrating through to the Earth’s surface, daily temperatures away from the coast would fall to 5 to –13 degrees Fahrenheit. This was the ‘nuclear winter’; crops would not grow; farm animals would die from radiation poisoning as would people. Areas throughout the world unaffected by actual bomb explosions would be affected by the ‘nuclear winter’ as the winds would carry radiation worldwide. Once the dust had settled the Sun’s rays would once again get to ground level. However, the ozone layer would have been so weakened that much higher ultra-violet radiation would cause severe damage to the immune system to those humans who had survived.

Scientists at the conference estimated that just 8 days after a nuclear attack, world temperatures would have collapsed with even sub-Saharan Africa and the Amazon Basin experiencing daytime temperatures that would hover around the 0 degrees Celsius mark.

The conference concluded with the following conclusion:

“In the aftermath of a 5,000 MT nuclear exchange, survivors would face extreme cold, water shortages, lack of food and fuel, heavy burdens of radiation and pollutants, diseases, and severe psychological stress – all in twilight or darkness. It is clear that the ecosystem effects alone resulting from a large-scale thermo-nuclear war would be enough to destroy civilisation as we know it in at least the Northern Hemisphere. These long-term effects, when combined with the direct casualties from the blast, suggest that eventually there might be no human survivors in the Northern Hemisphere. Human beings, other animals, and plants in the Southern Hemisphere would also suffer profound consequences.”