Climate change
Climate change is the slow case: a chronic threat that works through food, water, coasts, health and the stability of states. The mainstream scientific assessments do not project human extinction. The concern is compounding, irreversible change and what it does to societies that have no spare capacity.
Why it is in scope
We apply the same test as everywhere on this site: what is the credible pathway to civilisational-scale harm? For climate the candidates are crossing irreversible thresholds, correlated failures across food-producing regions, and the knock-on effects of both on migration, conflict and government. We say how strong the evidence is for each, and we report the central estimates, not only the worst cases.
Articles
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One point five, and counting
The world is running at or above the 1.5°C line in most months of 2026 with a strong El Niño building. What the numbers say, and how little the policy trajectory has moved.
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Tipping points: where the evidence is firm, and where it is not
Coral reefs, ice sheets, the Atlantic circulation and the food system. A system-by-system account of what is established, what is contested, and what would make it existential.
Key numbers
| Measure | Latest | Source |
|---|---|---|
| Global temperature above 1850–1900, 2025 | 1.47°C (Copernicus); 1.44°C (WMO) | Copernicus; WMO |
| September 2026 above 1850–1900 | 1.63°C, second-warmest September | Copernicus |
| Atmospheric CO₂, Mauna Loa, May 2026 | 432 ppm (up 1.8 ppm in a year) | Scripps; NOAA |
| Remaining 1.5°C carbon budget, start of 2025 | about 130 GtCO₂, roughly three years of emissions | Indicators of Global Climate Change |
| Projected warming by 2100 | 2.8°C on current policies; 2.3–2.5°C if all national pledges are met | UNEP Emissions Gap Report 2025 |