This quiz application from the Sierra Club offers exciting information on that basic of most human needs - air, and its impact in our daily lives. Air is good: it's all that stands between us and outer space. This application explores our atmosphere with wide-ranging inquiries and casually erudite answers. Where is the planet's cleanest and dirtiest air found? Why do divers get the bends? This application addresses global warming, the Kyoto Protocol, CFCs and the ozone layer, and cow digestion. A portion of this mobile application's sales proceeds are donated to the Sierra Club for environmental protection causes.