Nuclear War

The convergence of climate-induced resource scarcity (water, arable land), geopolitical rivalries (US-China, NATO-Russia, India-Pakistan), and the erosion of arms control treaties makes a nuclear conflict the most immediate existential threat. As food and water shortages intensify, nations may adopt aggressive postures to secure supplies, increasing the risk of miscalculation. A regional conflict could draw in major powers, triggering a full-scale nuclear exchange. The resulting nuclear winter would collapse global agriculture, leading to mass starvation and the end of organized human civilization. Unlike slower-moving threats like climate change or AI, nuclear war could unfold within hours, leaving no time for course correction.