Nuclear Conflict Could Alter the Conditions of Our Oceans

What do Pakistan, France, U.K., India, U.S.A., Russia, and many other countries have in common? Each have hundreds of nuclear bombs. If any future conflict were to go nuclear, the effects on the attacked countries would obviously be darkly immense. What’s less obvious is the global impact. As cities burn from the massive explosions, their ashes are lofted high up into atmosphere, shielding the Earth to an extent from the Sun’s light. The effect is abrupt global cooling known as nuclear winter.

Climate scientists have long understood that huge amounts of tiny particulates (like dirt, ash) in our upper atmosphere can cause quick cooling, lasting for a few years. However, scientists haven’t looked as deeply into how a fast-cooling climate can affect other parts of the Earth – specifically the ocean. A research team determined that all of our oceans would change in two fundamental ways from a regional, nuclear conflict: the oceans would become less acidic, and the calcium carbonate in their waters will dissolve more readily. Calcium carbonate is the chemical that comprises many animal’s shells including coral reefs. The findings were published recently in Geophysical Research Letters.

Moving past the macabre context for these changes on our oceans, the two effects are contradictory at first blush. Recent ocean acidification, caused by CO₂ dissolving into its waters, has drawn concern for marine animals because more acidic water better dissolves their calcium shells. Now, these scientists report a scenario where less acidic water accompanies the same problem. Why? It’s because there’s more ways that one to coax calcium carbonate into dissolving. Lower temperatures also increase its solubility (and lower temperatures incidentally tends to lower ocean acidity as well). Essentially, the authors discovered that many carbon-shelled marine animals may be threatened despite decreases in acidity, not because of it. There’s also the concerning question of how well all marine life can handle abrupt changes in acidity. The change in acidity from a large-scale, regional nuclear conflict would be significantly more abrupt than the “gradual” ocean acidification we’ve experienced over the past half century.

The scientists simulated two potential conflicts as examples to reach their conclusions. The main one is Pakistan and India. Each is suspected of owning more than 200 nuclear warheads and have been skirmishing with each other since the late 1940s. In some cases, the skirmishes escalated to all-out war.. The other is U.S. and Russia. While nuclear conflict may seem less likely with these two countries, they do have around 90% of the world’s estimated 14,000 nuclear bombs. The U.S. and Russia unloading their arsenals on each other is the scientists’ worst-case scenario.

While the effects on the ocean are intriguing to consider, the magnitudes of the conflicts the scientists assess are extreme and represent a worst-case scenario. The U.S.-Russia conflict they simulate is roughly equivalent to hundreds of Hiroshima-size cities being destroyed. The concern regarding the effect on oceans might not be something you’ve considered before and is interesting to investigate. But at that level of nuclear war, there’s likely already a long list of anxiety-inducing consequences spreading across the globe.

Managing Correspondent: Jordan Wilkerson

Original Article: The Potential Impact of Nuclear Conflict on Ocean Acidification, Geophysical Research Letters