As the world rushes to reduce the negative impacts of climate change, ambitious sub-national actors are rising to the fore. The recent One Planet Summit exemplifies this trend. Earlier this month…

Prashant Kapoor, Marc Forni |

In Mali, residents of Timbuktu take part in the maintenance of the Djingareyber Mosque, a World Heritage Site, applying traditional repair techniques. (Tiecoura Ndaou / UN Photo) Imagine a city…

Sameh Wahba, Barbara Minguez Garcia |

​Today, a quarter of the world’s population lives in urban “agglomerations”—supersized metropolitan areas that cut across jurisdictional boundaries and bring together one or more cities along with…

Ede Ijjasz-Vasquez, Philip E. Karp, Maria Angelica Sotomayor |