Multidecadal global cooling and unprecedented ozone loss following a regional nuclear conflict

Abstract

This study simulates the global impacts of a regional nuclear war with an Earth system model that includes atmospheric chemistry, ocean dynamics, and interactive sea ice and land components. Following a limited nuclear war using 100 low-yield weapons, the model shows that self-lofting smoke would spread globally, heating the upper stratosphere and cooling the surface for more than two decades. This would cause an unprecedented stratospheric ozone loss, with average ozone columns depleted by 20% and up to 50% at polar latitudes, leading to severe increases in UV radiation. Changes in the global climate would include a drop in global temperatures by 1.6 K, a 6% global precipitation loss, and a significant expansion of sea ice that would persist over more than a decade. Regionally, the growing season would be reduced by 10–40 days per year for 5 years, and agricultural productivity in many regions would be crushed. The severe climatic perturbations, including stratospheric ozone loss, UV enhancement, killing frosts, sharp precipitation shifts, and sea ice expansion, would significantly threaten ecosystems, including fisheries, and human food supplies, locally and globally. – AI-generated abstract.