City transitions infrastructure innovation, green economy and the eco-city

Three radical and interconnected transitions are central to sustainable urban development in the 21st century: transition to a green economy, to sustainable urban infrastructures and to eco-cities. They are framed against a formidable set of challenges to urban sustainability and resilience now confronting all societies as identified by Newton and Doherty. These include resource constraints, climate change, extreme events exhibiting shorter return periods, population growth, urbanization and built environment intensification, biosecurity, financial uncertainty, failing infrastructures, widening socio-demographic disparities and fragmenting social and human capital. This chapter explores the essential features of each prospective transition, some of the critical cross-connections, the barriers to change as well as emerging pathways for transformation. A common feature for all transitions is the set of normative goals that they address, viz. using resources more efficiently and reducing non-renewable resource consumption, reducing emissions and utilizing wastes as resources, restoring environmental quality, enhancing human wellbeing, and developing human settlements that are liveable, productive, environmentally sustainable and socially inclusive.