The US and Russia have recently agreed to hold talks on the New START Treaty, the only accord left regulating the two largest nuclear arsenals in the world. While this is undoubtedly good news, we must not allow it to lull us into complacency. Global events this year, most notably in Ukraine, have raised fears of a nuclear conflict to levels not seen since the cold war. There are more than 10,000 nuclear warheads remaining in the world, and the Kremlin’s language regarding weapons of mass destruction has became increasingly threatening in 2022.

Beyond the horrible fates of victims in the strike zones, a large-scale nuclear exchange would profoundly alter the climate system as we know it, while more limited scenarios could have a devastating impact. An ever-growing body of work has shown that even a local nuclear conflict could usher in a climate catastrophe. As marine scientists, we have considered what this could specifically mean for the world’s oceans.

Global famine and climate breakdown

In 1982, a group of scientists including Carl Sagan began to raise the alarm on a climate apocalypse that could follow nuclear war. Using simple computer simulations and historic volcanic eruptions as natural analogues, they showed how smoke that lofted into the stratosphere from urban firestorms could block out the sun for years.

They found that this “nuclear winter”, as it came to be called, could trigger catastrophic famine far from the location of the war. Ronald Reagan and Mikhail Gorbachev, leaders of the United States and Soviet Union in the 1980s, both cited this work when they declared that a nuclear war could not be won.

The contemporary threat has prompted a new era of research into the potential climate impact of a nuclear war. Using the latest computational tools, we have investigated what the consequences would be for all life on Earth. In our most recent research, we show that a nuclear conflict would massively disrupt the climate system and cause global famine. It could also dramatically disturb the ocean and its ecosystems for decades and potentially thousands of years after a conflict.

Read full story https://theconversation.com/even-a-limited-nuclear-war-could-devastate-the-worlds-oceans-heres-what-our-modelling-shows-193900.