Geoengineering cities to stabilise climate

Geoengineering typically refers to planetary-scale or perhaps regional-scale technological responses to the deleterious effects of human-induced climate change. This paper explores the idea that urbanisation could constitute a successful form of distributed, bottom-up geoengineering. Through the redesign of existing urban areas and the creation of more efficient new ones, per capita energy consumption and carbon dioxide generation could potentially be radically reduced. However, implementing these changes requires a combination of new technology and altered behaviour, coordination across sectors and geography, and unusually strong political action. In particular, civil engineers and economists would need to create methods for determining the most cost-effective ways for each city to become more resource efficient. Urban redesign carries a lower risk and offers more ancillary benefits than most other geoengineering schemes. Given the potentially catastrophic consequences of global warming, engineers, planners and politicians need to calculate how quickly and extensively cities can change to become positive forces for repairing the climate.