Even the smallest nuclear war would devastate ocean systems, causing sharp declines in fish stocks, expanding ice caps in coastal communities and changes in ocean currents that would take decades or more to reverse, according to a Rutgers researcher and an international team of geoscientists. , led by Cheryl S. Harrison at Louisiana State University.
“Our model is the first large-scale effort to quantify the effects of nuclear war on the oceans,” said Alan Robock, professor emeritus of climate science in the Rutgers Department of Environmental Sciences. and co-author of the study published in the journal American Geophysical Union Advances AGU.
To model marine responses to nuclear conflict, Robock and his colleagues simulated a major US-Russian war and several smaller Indo-Pakistani wars. By examining the four countries’ nuclear arsenals and potential targets, the researchers calculated how much soot would be dispersed through the atmosphere by the resulting firestorms and block out the Sun.
The researchers then used the Community Earth System Model (CESM), a climate simulation tool supported by the National Center for Atmospheric Research, to determine the short- and long-term effects of atmospheric soot on ocean functions.
In the US-Russian War Scenario, shortwave solar radiation was reduced by 70% and the global average surface temperature decreased by 7 degrees Celsius (12 degrees Fahrenheit) in the first few months, with more extreme cooling in the northern hemisphere. In turn, the Arctic sea ice expanded by 10 million square kilometers (4 million square miles), covering more than 50% more area, including normally ice-free coastal regions that are important for fishing, aquaculture and shipping.
In all scenarios – from the detonation of a hundred warheads to thousands – the ocean “does not return to the pre-war state when the smoke clears”, according to the study. “Instead, the ocean takes decades to return to normal, and parts of the ocean would likely remain in the new state for hundreds of years or more.”
Along with expanding sea ice and developing what researchers call a “little nuclear ice age,” the cooling would alter ocean currents, upend ocean macronutrients, and deplete fish stocks by about 20 percent. during the first decade after the war.
“A nuclear war would be a significant planetary tipping point,” Robock said. “With Russia at war with Ukraine and President Vladimir Putin threatening to use nuclear weapons, these findings are a strong warning that the world simply cannot go down this path.”