Over the last few decades, environmental scientists have played a critical role in tracking and describing the flows of urban resources such as energy, water, materials, wastes, greenhouse gases and chemical contaminants through cities, their regions and the global commons. There have been major technological advances in environmental chemistry, analytical instrumentation and numerical modelling of the transport of contaminants through air, water, soil and biota. There is now a much greater appreciation of the complexity of biogeochemical, hydrological, social and economic interactions that affect the behaviour of chemical contaminants in urban, industrial, agricultural and natural ecosystems.Arguably, this past emphasis has been on the descriptive and predictive approaches to urban environmental research with a strong emphasis on the biophysical, chemical, biogeochemical, hydrological and atmospheric sciences. The emerging challenge is how environmental scientists can more effectively bring their knowledge to those decision-makers who are responsible for changing urban and industrial processes that cause environmental impacts in the first place. As the global urban population grows, there are a range of new and complex urban climate adaptation challenges and opportunities in the built environment. These challenges include housing the vulnerable, improving indoor air quality, lowering health impacts in cities and adaptations to heat stress. The complexity and scale of these challenges will require environmental scientists to work collaboratively with other urban professionals, including engineers, planners, designers, economists, policymakers, managers and lawyers, and communities to bring about climate adaptation in urban environments.