Overview
- The UNEP report Limiting Overshoot, published on Wednesday, September 2, 2026, concludes the world will likely cross the Paris 1.5°C limit within years and reframes strategy toward minimising any overshoot, peaking warming and then driving temperatures back down.
- Even full implementation of current national pledges would likely produce a peak near about 1.8°C, while current policies could push median warming to roughly 2.6°C by 2100, showing a large gap between pledges and policies.
- Breaching 1.5°C raises the odds of stronger heatwaves, floods, fires, faster glacier and ice‑sheet loss, rising seas and a higher risk of irreversible tipping points such as collapse of parts of the West Antarctic or Greenland ice sheets, AMOC disruption, or Amazon degradation, and some harms will be permanent with limits to adaptation.
- Bringing temperatures back below 1.5°C would require substantial carbon dioxide removal beyond tree planting—which UNEP says can deliver at most about 0.1°C of cooling—so reliance on novel CDR methods faces major technical, cost and governance uncertainties.
- UN leaders and the report call for immediate, sustained mitigation including faster fossil‑fuel phaseout and deep methane cuts, scaled finance and governance for adaptation and CDR, and equity‑focused policies to protect vulnerable communities such as small island states and mountain populations ahead of COP31.