Ozone layer may be on the mend

Recent research findings by European scientists suggest that man’s efforts to protect the environment are beginning to pay off. Ozone data collected by a number of satellite stations indicate that the ozone layer is gradually beginning to recover.

Ozone is a protective layer in the stratosphere that acts as a sunlight filter, shielding life on Earth from harmful ultraviolet rays that can lead to skin cancer and cataracts. The gradual depletion of this protective layer, monitored in the second half of the twentieth century, had scientists ringing alarm bells and led to the signing of the Montreal Protocol in 1987- an international agreement to reduce ozone depleting emissions adopted by 24 countries. For close to two decades there was little sign of improvement but the last few years indicate that a combination of atmospheric circulation and man’s protective measures may have triggered a gradual improvement –particularly visible over the northern hemisphere. The Czech Hydro-Meteorological Institute issued a report this week saying that after 25 years the ozone layer above the Czech Republic had returned to “normal”. Dr. Karel Vaníček from the Solar and Ozone Observatory of the Czech Hydro-Meteorological Institute explains:

“Our ground base monitoring systems and satellite instruments show us that this phenomenon is typical for the major part of the middle and higher altitudes of the Northern hemisphere. During the last ten years we ascertained by our measurements that the amount of ozone-depleting substances in the stratosphere was decreasing but the effect of this trend in terms of increasing ozone had not been identified globally. In 2010 measurements showed without a doubt that the ozone layer was being replenished thanks to man’s contribution in protecting the environment, but mainly due to the positive circulation processes.”

Is that a temporary phenomenon then?

“Yes, it is a temporary phenomenon, but for us it is important to see if, in the coming years, the frequency of such years with increased total ozone or thickness of the ozone layer will increase. If this situation is repeated in the next five or ten years then we can say that we are in a new phase of the recovery of the ozone layer.”

Although the situation over the Northern hemisphere currently shows a marked improvement the ozone hole over the South Pole which forms every year in September is still there. Scientists say it may take 10 to 15 years before it starts getting smaller. And, in view of the adverse effect of global warming, they predict that even under the best possible scenario the ozone layer will not be fully restored until the second half of the 21st century.