Climate change from nuclear war's smoke could threaten global food supplies, human health

According to researchers from Rutgers University and the National Center for Atmospheric Research, nuclear war would result in many deaths. However, the smoke from the resulting fires could also cause climate change that can last up to 15 years and threaten global food production. Credit: Ready.gov
According to researchers from Rutgers University and the National Center for Atmospheric Research, nuclear war would result in many deaths. However, the smoke from the resulting fires could also cause climate change that can last up to 15 years and threaten global food production.

The Journal of Geophysical ResearchAtmospheres published the study.

Scientists have known for a long time that large-scale nuclear weapons attacks on cities and industrial areas can cause large-scale fires. The smoke in the stratosphere could cause climate change. This is why the term "nuclear Winter" was coined.

Researchers used a new climate model that included aerosols and nitric dioxide emissions for the first time to simulate the effects of sunlight absorption by smoke from nuclear wars.

This could result in the loss of most of our protective Ozone layer. It will take a decade for this to happen and it will cause several years of very high ultraviolet light at Earth's surface, further threatening human health and food supply.

"Although we knew that ozone would be destroyed in a nuclear war, and that would cause enhanced ultraviolet light at Earth's surface, if there were too many smokes, it would block out ultraviolet light," stated Alan Robock, a Rutgers University-New Brunswick Distinguished Professor in Environmental Sciences. "Now, we have quantified the effect of smoke on how this would work for the first-ever time and calculated how it would be done.

The study found that the enhanced ultraviolet light would start within one year for a five-million tons of soot-generating nuclear war between India & Pakistan. It would take eight years for a global war between Russia and the United States to begin if it generated 150 megatons. The effects of intermediate levels of smoke would be in the middle between these extremes.

Heating in the stratosphere, and other factors, would cause a 15-year-long decrease in the ozone column. This would result in a loss of 75% globally and 65% in the tropics. This is much higher than the 1980s predictions, which were based on large nitrogen oxides injections and did not consider the effects of smoke.

The global column ozone would drop by 25% in the event of a nuclear war. Recovery will take 12 years. The recovery time is faster than in previous simulations, but the lifetime of soot in these simulations is shorter.

Robock stated, "The bottom line was that nuclear war will be worse than we thought and must be avoided." "For the future, we have done other work and calculated how agriculture would change depending on changes in temperature, rainfall, sunlight, and sunlight, but have not yet considered the effects of UV light. The ultraviolet light could also cause damage to animals, such as us, and increase the risk of developing cancer or cataracts.

Further information: Charles G. Bardeen and colleagues, Extreme Ozone loss following nuclear war results in enhanced surface ultraviolet radiation, Journal of Geophysical Research - Atmospheres (2021). Information from Journal of Geophysical Research – Atmospheres Charles G. Bardeen et. al., Extreme Ozone loss following nuclear war results in Enhanced Surface Ultraviolet radiation, (2021). DOI: 10.1029/2021JD035079