This chapter presents the key theme of this book – sustainable pathways for cities and regions. Given current trends most of the expected nearly 10 billion people by 2050 will live in cities, and most of those cities will be on the coast at least in the first half of the twenty-first century. The impacts on climate change, if not managed now, will result in coastal retreat, uninhabitable areas due to drought, flooding, fire and air pollution affecting the future planning and design of urban settlements. Some cities may even go underground. As cities continue to expand into megacities along the seaboards of China, India and the United States, the risks will only increase. Choices are to be made. This chapter opens up the key discussions for alternative pathways for a more sustainable urban future – one pathway is to continue with business as usual, ignoring scientific advice on climate change, placing more and more people in harm’s way in the future; the second is to accept the current global agreements and work towards more green solutions where possible; and the third is to rise to the challenges of the urban world and, in the first instance, reduce emissions and then actively engage with local communities to implement sustainable pathways for our cities and regions. Key cities introduced later in this book are explored for leading practice: Canberra, Kuala Lumpur, Copenhagen and New York City featured as well as other examples in Melbourne, Seoul and Stockholm. The chapter outlines the approach and structure of the book; the subsequent chapters lead to a set of seven sustainable pathways proposed to improve implementation of sustainable solutions in an urbanising world adapting to social, economic and environmental change.