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Publication of the FY2011 Annual Report on Ozone Layer Monitoring

August 24, 2012

The Ministry of the Environment of Japan has compiled its FY2011 annual report on ozone layer monitoring, covering the status of (i) ozone layer, (ii) atmospheric concentration of ozone depleting substances (ODS), and (iii) solar ultraviolet radiation, pursuant to the Law Concerning the Protection of the Ozone Layer through the Control of Specified Substances and Other Measures (the "Ozone Layer Protection Law").

(i) The current condition of the ozone layer
- The global total ozone has been largely reduced from 1980s to the first half of 1990s. After the end of 1990s, it has been showing little increase. However, the status of total ozone remains depleted compared to 1979.
- The ozone hole formed over Antarctica every spring expanded from the 1980s to the 1990s, and remained stable with year-to-year variable since then. The Antarctic ozone layer is still in critical condition.
- In the high-latitude areas of the Northern hemisphere, recent total ozone remains low compared with values observed during the 1980s. The largest scale of the ozone depletion in the past was observed above the high-latitude areas of the Northern hemisphere spring in 2011.

(ii) Concentration of ozone-depleting substances in the atmosphere
- In the mid-latitude areas of the Northern hemisphere, atmospheric concentrations of chlorofluorocarbons (CFCs) have been decreasing very slowly, as observed in Hokkaido. On the other hand, concentrations of hydro chlorofluorocarbons (HCFCs) have been rapidly increasing. The concentrations of hydro fluorocarbons (HFCs), which do not deplete the ozone layer but has high greenhouse effects, have been rapidly increasing.
- CFCs stay in the atmosphere for a very long time; therefore, it is predicted that from now on, its concentration will reduce very slowly due to complete abandonment of its production. As for HCFCs, it is predicted that its concentration in the atmosphere will increase and reach its peak within 20 to 30 years, and then start decreasing.

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