Climate Collapse

Based on accelerating global trends, the most likely world-ending scenario is irreversible climate collapse. Rising temperatures, driven by unchecked greenhouse gas emissions, are exacerbating extreme weather events, sea-level rise, and biodiversity loss. By mid-century, tipping points like melting permafrost and collapsing ice sheets could release massive methane stores, triggering runaway warming.

This would lead to widespread crop failures, mass migrations, and societal breakdowns as billions face famine, water scarcity, and uninhabitable regions. Geopolitical tensions over resources could spark conflicts, but the root cause—environmental tipping—would render recovery impossible, culminating in human extinction or near-extinction within centuries. Technological and societal adaptations are outpaced by the scale of change, making this the predominant existential risk.