HOW TO BUILD A ‘SPONGE CITY’ Meanwhile, in Berlin: Landscape architects and designers in the German capital have identified a strategy designed to keep water where it lands, to imitate the natural water cycle otherwise absent from built-up areas. The goal: To cool environments otherwise dominated by hard and reflective surfaces by deploying green roofs and façades on buildings and urban wetlands and swales at ground level. [Bloomberg Businessweek] Video: Bloomberg Businessweek