(CBS) It’s a surprising but true fact: the number one cause of global warming isn’t cars, but buildings.

All those office complexes, schools and homes produce about half of all glacier-melting pollution, says CBS News correspondent David Pogue.

But not the 20 houses built for the 2007 Solar Decathlon, a competition for colleges that’s run by the U.S. Department of Energy. Not a single one creates any global-warming pollution.

The goal of the competition is to demonstrate what is possible in terms of solar energy.

http://www.cbsnews.com/stories/2007/11/01/sunday/main3441061.shtml