I have blogged before about the idea of nuclear winter. If there is a nuclear conflict in which at least a hundred nuclear warheads are detonated, the soot, soil and smoke thrown into the atmosphere would shut out sunlight for years and crop failures would kill billions that survived the actual conflict. Now scientists are studying what effect a nuclear war might have on the world’s oceans.
Nicole Lovenduski at the University of Colorado Boulder led the team that carried out the new study. Their report on the study was published in the journal Geophysical Research Letters in January of this year. They used estimations of the amount of soot thrown into the atmosphere in four different nuclear war scenarios. The soot was measured in teragrams which represent one trillion grams or one thousand kilotons. Three of the scenarios involved different levels of nuclear war between India and Pakistan with five teragrams, twenty-seven terragrams and forty seven terragrams of soot injected into the atmosphere. The fourth scenario dealt with an all-out nuclear war between Russia and the U.S. with one hundred and fifty terragrams of soot.
Michelle Taylor at LaboratoryEquipment.com offered a summary of the effects of the least powerful nuclear exchange involving five teragrams of soot. She wrote, “… the researchers found that the conflict would likely generate huge amounts of black carbon high in Earth’s atmosphere, causing the globe to cool. Interestingly, the researchers found that the fallout from a nuclear detonation would come in two stages: the first within one year, and the second between three and five years post-bombing.
Soon after denotation and no longer than one year later, global climate models showed the acidity of the world’s oceans would likely dip. Years later, the world’s saltwater would begin to suck up more carbon dioxide from the air. Supplies of carbonate in the oceans would shrink, removing the key ingredient that corals use to maintain their reefs and oysters use to sustain their shells.”
Lovenduski told Taylor that there would be a severe disruption of the food web in the oceans that would definitely have a major impact on the human food chain. Taylor wrote that there are more than three billion people who are dependent on ocean fisheries for food and/or income. Crustaceans in the oceans would heavily impacted.
Brian Toon at University of Colorado Boulder was co-author of the report. He said, “This result is one that no one expected. In fact, few people have previously considered the impact of a nuclear conflict on the ocean.” Lovenduski added, “A lot of things would change in the oceans once you dim the lights [via soot in the atmosphere]. The way the water moves in the ocean, for example, is sensitive to how much heat it gets from the atmosphere …
It makes me question whether organisms could adapt to such a change. We’re already questioning whether they can adapt to the relatively slower process of man-made ocean acidification, and this would happen much more abruptly.”
Lovenduski said that it was too early to say exactly what the fate of shelled creatures would be in the event of nuclear war. She hopes that her research group’s conclusions will shine more light on how devastating even a limited nuclear exchange would be. She wrote, “I hope this study helps us to gain perspective on the fact that even a small-scale nuclear war could have global ramifications.”