Jaime Lerner, the former three-time mayor of Curitiba, Brazil, is credited with halting his predecessor's plan to replace Curitiba's historic buildings with a network of roads, instead making it "the greenest city on Earth." How did Lerner's background as an architect and city planner likely influence the city's now - enviable sustainability strategy? How might the city be different if his main area of expertise had instead been finance or commercial development?