The Montreal Protocol is a landmark international treaty
signed by all 198 countries around the world in 1987.
After we discovered that the emissions of the very long lived
gases such as chlorofluorocarbons can go into
the atmosphere and destroy the ozone layer, these countries
around the world come together and sign this protocol to reduce
the emission of this long live gases.
My name is Qing Liang, I am a research scientist working in
NASA Goddard Space Flight Center.
Due to the successful cooperation between the
scientific community and the policy makers, the atmospheric
concentration has been declining since the 1990s. And then the
stratospheric ozone layer is on the road to recovery.
CFC 11 is one of the most important chlorofluorocarbons
gases, the scientists around the world has always been
continuously monitoring the atmospheric concentration of
CFCs from the global observation of stations. A few years ago,
Dr. Steve Montzka from NOAA ha noticed that the globa
concentration of CFC levels ha actually been declining slowe
than expected. That's inspire the community to think ther
might be additional emission that we're not aware of. Th
scientists has also used th atmospheric observations o
these gases from a Korea station and found out that abou
half of the emission was comin from increasing emissions i
eastern China
So what I do is really taking my model get some background
calculation and provide them to the University of Bristol teams
as well as the other modeling teams. They use that as the
underlying atmospheric distribution of these gases. As
the problem was detected, and these papers were published, it
seems that the Chinese government has taken effective
measures to stop the illegal production and usage of these
gases. This is absolutely detective work. This is reason
why we say although we're very happy with the progress of the
Montreal Protocol it's of crit cal importance for NASA, NOAA, a
ong with other internati nal agencies to continue to
ake atmospheric observation of these gases. Without t
ese measurements, it is not poss ble for us to detect the problem
and take action to solve the prob