Scientists continuously monitor ozone-depleting gases

Today's Video of the Day from NASA Goddard describes how computer models helped scientists pinpoint the source of an ozone-depleting gas. In 1987, countries around the world signed the Montreal Protocol in an effort to reduce emissions of long-lived gases such as chlorofluorocarbons, which can destroy the ozone layer.  Scientists around the world are continuously monitoring the atmospheric concentration of these gases, particularly CFC-11. A few years ago, NOAA expert Dr. Steve Montzka noticed that CFC levels have been declining slower than expected across …