They say there's a hole in the ozone layer, caused by our use of CFC's. But what are CFC's and how do they cause harm? NASA helps to explain at this site, which explores the topic and charts the depletion of the ozone since 1979. It's a visually engaging look at the issue though still images and videos.
NASA
• Pictures and/or Illustrations
• High School Middle School Elementary School
Mark Hannah
