Recently I and two co-authors – Kwesi Quagraine and Erle Ellis – proposed a new metric for how to measure and track the progress of the clean energy transition worldwide. This was published as a Commentary in Nature on 26 January 2026 under the title: ‘As we breach 1.5 °C, we must replace temperature limits with clean-energy targets’. We’ve had a lot of interest in the Clean Energy Shift, and lots of questions to field via email and social media.