Cities’ role in the climate transition is more important than ever, and they are leading on climate action, but significant structural barriers hinder progress. The EU-funded NetZeroCities initiative will support European cities in significantly reducing greenhouse gas emissions to achieve climate neutrality by 2030. It recognises the need for cities to develop new capabilities and adopt new systemic approaches. Helping cities overcome structural, institutional and cultural barriers, the initiative will support a series of Pilots to help drive rapid learning about achieving the required systems change.