The French Alps' premier ski destination, Chamonix, lies in the shadow of the Mont Blanc mountain range. Its snow-covered slopes give off a pristine glint in the sunlight. At its apex, Mont Blanc (15,781 feet) overlooks everything, a symbol of the resort's long, rock-ribbed traditions. It is the highest peak in Western Europe. But concerns about air quality, as well as troubling, climate-related changes in the landscape of the surrounding mountains, are causing local government and conservation groups to rethink how much future tourism the delicate ecosystem can handle.

In the wooded hills outside Knoxville, Tenn., researchers are bringing back a small but expensive slice of the '80s. Scientists at Oak Ridge National Laboratory are using a couple of newly constructed buildings -- a two-story brick-clad office building and a metal warehouse -- to see how energy conservation might be improved. They were built to the requirements of decades-old building codes.