How we design our cities over the next four decades will be critical for our planet. If we continue to spill excessive greenhouse gas into the atmosphere, we will run out of time to keep our global temperature from increasing. Since approximately 80% of greenhouse gases come from cities, it follows that in the design of cities lies the fate of the world. As urban designers respond to the critical issue of climate change they must also address three cresting cultural waves: the worldwide rural-to-urban migration; the collapse of global fertility rates; and the disappearance of the middle class. In Five Rules for Tomorrow’s Cities, planning and design expert Patrick Condon explains how urban designers can assimilate these interconnected changes into their work. Condon shows how the very things that constrain cities—climate change, migration, financial stress, population change—could actually enable the emergence of a more equitable and resource-efficient city. He provides five rules for urban designers: (1) See the City as a System; (2) Recognize Patterns in the Urban Environment; (3) Apply Lighter, Greener, Smarter Infrastructure; (4) Strengthen Social and Economic Urban Resilience; and (5) Adapt to Shifts in Jobs, Retail, and Wages. In Five Rules for Tomorrow’s Cities, Condon provides grounded and financially feasible design examples for tomorrow’s sustainable cities, and the design tools needed to achieve them.