A sustainable city, ecocity or ecopolis is an entire city edicated to minimizing the required inputs (of energy, water and food) and its waste output (of heat, air pollution as co2, methane, and water pollution.) Richard Register first coined the term "ecocity" in his 1987 book, Ecocity Berkeley: building cities for a healthy future Another leading figure who envisioned the sustainable city was architect Paul F. Downton, who later founded the company Ecopolis Architects.