'Green roofs' growing more popular (CNN)

NEW YORK (AP) -- An architectural organization has unveiled a new "green" roof for its own building to showcase a trend toward environmentally-friendly technology.

The leafy rooftop of the American Society of Landscape Architects (ASLA)building in downtown Washington is a model of the techniques used increasingly to cool temperatures, filter air, and lessen the burden on sewers by absorbing rainwater.