Single‑Month 1.5C Breach as Policy Signal

A single month that averages above 1.5°C (relative to pre‑industrial) functions less as a scientific permanent crossing and more as a political and policy trigger: it sharpens public perception, pressures governments on mitigation/adaptation funding, and focuses media and insurers on near‑term risks. Even if a breach is temporary (e.g., El Niño amplified), recurrent monthly exceedances will change the terms of policy debate and accelerate demand for concrete measures. — Treating transient threshold exceedances as decision‑relevant signals will shift political momentum, budget priorities, and public expectations about the feasibility and timing of Paris goals.