What would happen in the atmosphere if a nuclear war broke out? A new study that has taken into account the chemical reactions that would occur in the stratosphere, one of the lowest layers of the Earth and where the ozone layer is located, concludes that the latter would be seriously affected and, as a consequence, increase ultraviolet light, which is related to skin cancer, agricultural processes and even the survival of entire ecosystems.
The results that have now been obtained indicate that the damage to the environment could be more serious than previously believed , taking into account the damage from the initial warming effect of nuclear explosions, as well as the subsequent loss of the ozone layer .
“Although we suspected that ozone would be destroyed after a nuclear war and that would lead to an increase in ultraviolet light on the Earth’s surface, if there was too much smoke, it would block the ultraviolet light,” says climate scientist Alan Robock from Rutgers University of New Jersey. “Now, for the first time, we have calculated how this would work and quantified how it would depend on the amount of smoke.”
The researchers analyzed the impact of a regional and global nuclear war, with 5 megatons and 150 megatons of soot released respectively. What they saw is that a world war would cause an average loss of the ozone layer of 75% over the course of 15 years, while a regional war would cause a loss of 25% of the ozone layer in a period of 12 years.
According to the study, although the smoke would initially block the sun’s rays, after a few years stronger bursts of ultraviolet light would be produced that would reach the surface of the Earth due to the damage caused to the ozone layer.
Both the initial explosion, through chemical reactions with nitrogen oxides, and the smoke itself through heating and the reduction of photochemistry that interfere with natural atmospheric interactions, would contribute to the loss of ozone.
Ultraviolet light is related to a wide variety of situations such as skin cancer , agricultural processes and even the survival of ecosystems . If this, as a result of the destruction of the ozone layer, reaches us in greater quantity, the consequences would be very serious. And while a global war would be worse, a regional war would still be devastating.
“Conditions would change dramatically, and adaptations that may work at first will be useless when temperatures warm again and UV radiation increases,” says atmospheric scientist Charles Bardeen of the National Center for Atmospheric Research (NCAR) in Colorado. “Just as the smoke is clearing, this UV burst would come with completely different impacts on human health and agriculture .”
The first models of nuclear warfare that were developed in the 1980s envisioned a nuclear winter, with smoke from explosions and subsequent fires blocking out the sun and its heat. The models that have followed have considered how rising temperatures, as well as direct damage, could affect the ozone layer through warming of the stratosphere.
The present study, which has been published in the Journal of Geophysical Research: Atmospheres , concludes that you cannot escape the effects of nuclear war in the following decades, regardless of where you are on Earth .
“In addition to all the deaths that would occur almost immediately, the effects of weather and the effects of ultraviolet rays would be widespread,” says Bardeen. “They are not local in the place where the war is taking place. They are global, so they would affect us all.”
Fuente: Bardeen, C. G., Kinnison, D. E., Toon, O. B., Mills, M. J., Vitt, F., Xia, L., et al. (2021). Extreme ozone loss following nuclear war results in enhanced surface ultraviolet radiation. Journal of Geophysical Research: Atmospheres, 126, e2021JD035079. https://doi.org/10.1029/2021JD035079
