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 simulate a conflict at the Ukraine-Russia border that releases five million-tons of black carbon (BC) 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 by ~ 6 years. Long-lived radionuclides transported with BC disperse globally, with ~ 40% depositing in the Southern Hemisphere. These findings underscore the importance of nuclear-risk reduction and provide a robust benchmark for food-security and humanitarian-impact assessments.