From Milan to New York to Tokyo, the buzziest fashion statement is ... sustainability. One Italian brand is replacing nylon fiber with a material made from ocean plastic; a California consignment shop is inspiring a generation of thrifters to reduce their carbon footprint; and a denim shop in Tokyo's ritziest neighborhood aims to make its operations carbon-neutral by 2050. We'll hit the ateliers and runways to see how cutting-edge designers are trying to keep us -- and our planet -- looking good.