ABSTRACT
Demographers predict that within the next 40 years world population will continue to grow. All of that growth will take place in cities, which must grow either by expanding outward or by increasing in density. During that same period of time, much of our already-aging urban infrastructure will reach the end of its useful life and will need to be replaced. Cities will be impacted by a destabilized climate with drought, heat waves, altered growing conditions, increasingly severe storms, and sea levels at least several feet higher than today. At the same time, the passing of peak oil will mean an end to the era of cheap and available fossil fuels on which cities currently depend.
