Although it is obvious that nuclear war would be devastating for our planet and us, how disastrous? A new study shows the devastating effects of nuclear war smoke on the atmosphere. The results are predictable.
These models are among the most detailed and up-to date ever used for the job. It also accounts for complex chemical reactions that could occur in the stratosphere (one of the lower levels in Earth's atmosphere).
The new findings show that environmental damage could be more severe than previously thought and may last longer, if you include damage from nuclear explosions' initial heating effects as well as subsequent ozone layer losses.
"Although we knew that ozone would be destroyed in a nuclear war, and that would lead to enhanced ultraviolet light at Earth's surface, if there were too much smoke, it could block out the ultraviolet light," states Alan Robock, climate scientist from Rutgers University, New Jersey.
"Now, for first time, we have calculated the mechanism and quantified the effect on smoke.
The impact of a global and regional nuclear war was analyzed by the team, which released 5 megatons and 150 gigatons respectively. Researchers found that a global war would result in an average loss of 75 percent to the ozone layer over 15 years. A regional war would cause a loss of 25 percent of the ozone layer over a 12-year period.
The study found that although smoke blocks the Sun's rays at first, stronger ultraviolet light bursts would occur within a few years due to damage to the ozone layer.
The loss of ozone would be caused by both the initial blast (chemical reactions with nitrogen oxides) and the smoke itself (heating and reduction of photochemistry, which interfere with natural atmospheric interactions),
There are many UV light variations that can be linked to everything, from skin cancer to agricultural processes to the survival and growth of whole ecosystems. Having more of it on the planet would have devastating consequences for everyone and everything who survived the initial blasts. Even though a global war is more dangerous, a regional one would still be catastrophic.
"Conditions will change dramatically," Charles Bardeen (atmospheric scientist at the National Center for Atmospheric Research, NCAR in Colorado) says.
"Just like the smoke is clearing away, you'd get this UV blast with totally different impacts on agriculture and human health."
In the 1980s, the first models of nuclear war predicted a nuclear winter. The explosions and subsequent fires would block out sunlight and heat. Later models considered how temperature rises and direct damage could impact the ozone layer via the heating of stratosphere.
It is important to remember that nuclear arsenals are constantly changing: countries such as India and Pakistan most likely have gained more weapons and stronger weapons while the US and Russia are experiencing a reverse trend.
This study will include as many of these considerations as possible in order to demonstrate the differences between regional and global nuclear war. The end result is that you can't escape the effects over the next decade, regardless of where you live on Earth.
Bardeen says, "In addition to all of the fatalities which would occur almost immediately," adds Bardeen.
These are not localized to the area where war is occurring. They affect everyone.
The research was published in Journal of Geophysical Research: Atmospheres.