In his book Planet of Slums, Mike Davis forecasts a bleak, almost apocalyptic urban future – one where there is widespread inequality and deprivation, where a majority of the urban population lives in squalor with inadequate access to basic services and with precarious employment. Although this future has not yet come to pass, there are large sections of urban populations that are increasingly vulnerable due to growing inequality, poverty, and environmental risk. However, urban regions also offer opportunities to tackle these challenges. Cities have been called “engines of economic growth,” with the ability to foster equitable development, raise the standard of living and provide economic opportunities to a wider population (Anand et al. 2014; Glaeser 2011; Sankhe et al. 2010). Cities are also extremely vulnerable to disasters and where the impacts of climate change will be felt most acutely, but they are also where some of the greatest opportunities to address these environmental challenges are emerging (Revi and Rosenzweig 2013; Revi 2009; Stone 2012).

Globally, we are at the cusp of an urban transition: 54 percent of the world's population now lives in urban centers (UN Population Division 2014). As a UN Population Division report on world urbanization prospects shows, Africa and Asia are urbanizing faster than any other part of the world: 90 percent of the urban population growth will be concentrated in these regions (ibid.). Much of this increase will take place in India and China, especially in small and emerging towns in these regions. As cities expand and push their boundaries, urban peripheries are experiencing rapid growth and development opportunities, but also the challenges that come with largely unplanned growth.