Nuclear Conflict in Eastern Europe: Climate Disruption & Radiological Fallout

Geopolitical tensions in Eastern Europe underscores the urgency of addressing the climatic and radiological consequences of a regional nuclear conflict. Using an Earth System Model, we explore the fallout from a hypothetical frontline conflict involving air- and surface-burst detonations near the Ukraine-Russia border, releasing substantial amounts of aerosol particles (Black Carbon (BC)) and radionuclides into the stratosphere. The extended stratospheric lifetime of BC induces hemispheric climate disruption: the Northern Hemisphere cools by ~1 °C in year-1, with anomalies of −5 °C in Russia and −4 °C in the United States; surface solar radiation declines by ~30 W m⁻² over the US; and precipitation decreases by ~40% across mid-latitude croplands. Stratospheric warming alters subtropical and polar jets, displacing the Intertropical Convergence Zone ~2–6° southward, delaying climate recovery. To contrast the impacts of a high- versus low-latitude nuclear conflict, we compare the hypothetical Ukraine-Russia conflict with the India-Pakistan case, the latter being the most extensively studied regional nuclear conflict in past literature. We examine its impacts on global and regional climate, the trajectory of long-term climate recovery, and both short- and long-term radiological fallout. These findings underscore the importance of nuclear-risk reduction and provide a robust benchmark for food-security and humanitarian-impact assessments.