Scientists Cut Worst-Case Warming Ceiling from 4.5°C to 3.5°C — Solar and Wind Deployment Credited

Leading climate scientists from the Scenario Model Intercomparison Project (ScenarioMIP) announced that the upper limit of the worst-case warming scenario has been revised down from 4.5°C to 3.5°C above pre-industrial levels by 2100. The revision directly credits the plummeting cost and rapid deployment of solar and wind power, which has made a high-fossil-fuel future increasingly implausible as a pathway. Current policy trajectory still suggests approximately 2.5°C of warming by 2100. The scientists cautioned that while the worst-case ceiling has been lowered, the best-case 1.5°C Paris Agreement target remains under threat, and urgent acceleration of the clean energy transition is still required. The findings will feed into future IPCC assessment cycles.