It has only been a few months since the passing of atmospheric chemist Dr. Mario Molina. Now are faced with the loss of yet another titan of atmospheric chemistry, Dr. Paul Crutzen, who shared with Dr. Molina the 1995 Nobel Prize in Chemistry.
Dr. Crutzen is primarily known for his contributions to ozone chemistry, particularly its destruction by NOx. His work as a chemist can perhaps only be surpassed by his work as an activist: warning international governments of deployment of supersonic jets which would inject NO directly into the stratosphere, developing the concept of a nuclear winter highlighted in his publication "The Atmosphere after a Nuclear War: Twilight at Noon," and coining our current epoch "the anthropocene," a climate period ruled by human activity.