The future of urban experimentation through ten critical lessons from decades of practice

Since the ratification of the Kyoto Protocol, the signing of the Paris Agreement, the adoption of the Sustainable Development Goals, and the New Urban Agenda, there has been a major growth of urban involvement in addressing sustainability challenges. This has sparked a thriving era for city governments around the world to engage with urban experimentation that aims to enable transformations towards low-carbon and more resilient, just and sustainable cities. Reflecting on insights from eight databases covering close to two thousand urban experiments, here we provide ten critical lessons about urban experimentation across three themes: key processes, politics and governance, and impact. We end with a call to action to empower and embed urban experimentation as an enduring governance practice, to develop whole-of-systems approaches across sectors, places and policy silos, and to design relational and institutional infrastructures that ensure continuous and reflexive approaches to the monitoring and evaluation of urban experimentation.