Many studies have documented the growing fragility of a majority of the globe's ecosystems. Policymakers and resource managers often frame such ecosystem challenges as primarily about protecting natural systems in rural areas. However, that conception misses a key part of the story: the rapid growth of urbanizing areas. Home to more than 50 percent of the world's human population for the first time in modern history, urbanizing regions concentrate pressure on ecosystem services, which are necessary to sustain healthy urban living conditions and vibrant commerce. This dramatic urbanization presents both challenges and opportunities for novel ecosystem services management. A transdisciplinary framework is needed to discover innovative solutions to these wicked problems because they involve complex linkages between natural and human systems that transcend any single discipline. The framework should integrate natural and social sciences with stakeholders' intimate knowledge of ecosystem services and urban systems. Here we describe such a framework for training scientists and managers and present four novel cases that illustrate ecosystem management solutions for urbanizing areas.