GOING GREEN: Marc Jacobs, Stella McCartney, Jil Sander, Burberry, Ralph Lauren, Calvin Klein, Donna Karan, Narciso Rodriguez and Versace are among the companies that have signed up for Earth Pledge's FutureFashion Jan. 31 runway show at Gotham Hall. Aside from kicking off New York Fashion Week, the event, in which the designers will create one-of-a-kind designs, is geared toward raising awareness about the need to use sustainable materials in the fashion industry. The aim is to promote renewable, reusable and nonpolluting materials and methods. Julie Gilhart, vice president of fashion merchandising at Barneys New York, has been key in pulling the event together, according to an Earth Pledge spokeswoman. Barneys, Lexus Hybrid Living and Pure & Natural are among the sponsors. For three weeks starting Feb. 1, Madison Avenue shoppers will have the chance to check out some of FutureFashion's creations in Barneys' store windows.