Global warming renders more than 20 percent of currently inhabited land thermally uninhabitable before 2050.

Question

Six frontier AI models put this at 3% by 20 Sept 2076. Full reasoning from every model.

WillHappen.ai · Accepted Answer

3% — the median of 6 frontier models, resolving by 2076-09-20.

Answer

Gemini (Google): 2% — Hitting 20% uninhabitable land before 2050 requires catastrophic warming (>4°C) that physics and emissions trajectories rule out. IPCC AR6 projects 1.5°C to 2.5°C warming by 2050; wet-bulb extremes above 35°C remain localized to narrow coastal and river basins. Present inhabited land spans 100M+ km²; covering 20M km² requires virtually all of South Asia, the Sahel, and the tropics to fail. A runaway methane feedback triggering >5°C warming by 2045 is the only plausible mechanism, carrying under 2% probability.

Answer

Claude (Anthropic): 1% — Requires wet-bulb extremes to make 20%+ of populated land unlivable by 2050, far beyond any credible climate projection. Even worst-case IPCC scenarios show dangerous wet-bulb extremes limited to small tropical/subtropical regions by 2050, not 20% of inhabited land. Human adaptation (AC, migration, infrastructure) means 'unlivable' thresholds rarely translate into abandonment of settlements at this scale. No credible climate model or peer-reviewed study projects anything close to 20% land abandonment due to heat by mid-century.

Answer

GPT (OpenAI): 12% — Crossing this threshold requires sustained extreme humid heat across several major populated regions, not isolated lethal events. IPCC pathways make dangerous wet-bulb heat more frequent by mid-century, but widespread >35°C wet-bulb conditions remain rare. More than one-fifth of inhabited land would require failures of adaptation, cooling, water and migration across South Asia, Gulf and tropics. I would raise this sharply if observations show recurring 35°C wet-bulb exposure over populous regions before 2040.

Answer

Grok (xAI): 3% — Whether routine >35°C wet-bulb covers >20% of today's populated land by 2050. CMIP6/SSP5-8.5 still yields only brief, localized exceedances by 2050, not 20% of inhabited area. Vecellio/Raymond physiology papers plus ~1.8°C median warming leave current hotspots livable with shade/AC; 20% needs ~4°C. Only an implausible climate-sensitivity jump or emissions explosion would change the outlook.

Answer

DeepSeek (DeepSeek): 2% — This needs a threshold no climate model projects this century, let alone by 2050. Wet-bulb 35C events are currently rare and localized; IPCC AR6 projects they remain confined to small regions even at 2-3C warming. Land area hitting routine fatal wet-bulb by 2050 is projected in the low single-digit percent, far below the 20% threshold. Even extreme scenarios (SSP5-8.5) don't reach 20% uninhabitable land by 2050; the statement would require a climate trajectory outside any published range.

Answer

Qwen (Alibaba): 3% — Requires wet-bulb temps to permanently exceed survivability across vast inhabited areas within ~25 years of today. Even RCP8.5 projections show <2% of land exceeding 35°C wet-bulb by 2050; 20% would require warming far beyond any credible scenario. Current inhabited land spans ~150M km²; losing 20% means ~30M km² becoming uninhabitable, which no climate model projects before 2100+. Would require either a climate sensitivity far above IPCC's 2.5-4°C range or a methane feedback cascade not observed in any current data.

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