The ARC3.3 Circular Economy in Cities Element is opening a call for case studies related to the successful application of circular economy in urban spaces. ARC3.3 case studies are designed to provide a detailed and action-oriented analysis of a specific climate change topic in a selected city. Case studies have a page length of 3 – 5 pages, are between 1200 – 2000 words, and have 2-3 high-resolution figures/images. Completed case studies will be uploaded to UCCRN's Case Study Docking Station with DOIs.