All scenarios / Earth systems
Climate Catastrophe
Slow, then all at once. Bring sunscreen.
What it is
Climate catastrophe doesn't mean the planet becoming uninhabitable overnight. It means warming that's severe enough to trigger cascading failures: crop losses, deadly heat, water shortages, mass migration and conflict, all piling up faster than societies can adapt. The danger rises steeply with each extra fraction of a degree, and the risk grows if tipping points such as ice-sheet loss or ocean-current collapse are crossed.
Why it ranks where it does
Climate risk is driven this season by a looming super El Niño, which the scientists cited by Reuters warn could cause around 450,000 heat-related deaths. It's forecast to peak in late 2026 and could strain food, power and water supplies into 2027. Because it lands on top of record warming, the near-term pressure is unusually high. We track live prediction markets on the El Niño event.
Evidence on the board
- A looming 'super' El Niño could lead to 450,000 heat‑related deaths, per experts cited by Reuters. Reuters ↗
- El Niño is forecast to peak in late 2026, threatening food, power and water into 2027. EY ↗
What the experts say
Most climate scientists don't expect warming alone to cause human extinction. Toby Ord estimates about a 1 in 1,000 chance of a climate-driven existential catastrophe this century. The higher risk is a long, grinding catastrophe that kills millions and destabilizes states. That's why climate ranks high on a board that measures civilization-scale harm, not just extinction.
What would move the number
Up
- A confirmed strong El Niño with crop failures in several breadbaskets at once
- Evidence that a major tipping point has been crossed
- Global emissions rising again
Down
- A weaker-than-forecast El Niño
- Rapid emissions cuts and adaptation spending
- Good harvests in 2027
Live signals we track
The baseline above is set from the evidence as of October 13, 2026. On the live board, your browser adjusts it in real time using these feeds. Chatter can only nudge a score in proportion to its evidence, so attention alone can't make an unlikely scenario look likely.
- Prediction market: Super El Niño this winter, 97.2% at snapshot Polymarket ↗
- Public attention: daily Wikipedia pageviews for Climate change
- Public attention: daily Wikipedia pageviews for Tipping points in the climate system
- Online chatter: Hacker News stories mentioning "climate change" this week vs. the prior eight weeks
Sources
- 80,000 Hours: Toby Ord's existential risk estimates
https://80000hours.org/articles/existential-risks/ - Wikipedia: Climate change
https://en.wikipedia.org/wiki/Climate_change - Wikipedia: El Niño–Southern Oscillation
https://en.wikipedia.org/wiki/El_Ni%C3%B1o%E2%80%93Southern_Oscillation - Reuters
https://www.internazionale.it/ultime-notizie-reuters/2026/10/11/middle-east-war-high-debt-levels-to-dominate-imf-world-bank-meetings-in-bangkok - EY
https://www.ey.com/en_gl/insights/geostrategy/geostrategic-analysis - Polymarket: Super El Niño this winter
https://polymarket.com/event/will-there-be-a-super-el-nino-this-winter-202627-20260721221614682
Baseline scores are an editorial threat index from 0 to 100 that combines current reporting with published expert estimates. They're meant for comparing risks, not as actuarial forecasts. See how the numbers work.