"We've detected unexpected decreases in the lower part of the stratospheric ozone layer, and the outcome of this result is that it's offsetting the recovery in ozone that we had expected to see", said William Ball, a scientist with the Physical Meteorological Observatory in Davos, Switzerland. However, the ozone layer swathes the whole Earth, the latest study reveals that the layer is getting thinned over the non-polar areas in the lower stratosphere.
After it was discovered that man-made chemicals were drastically damaging the global ozone, the 1987 Montreal Protocol was established to phase out the likes of chlorofluorocarbons (CFCs).
The ozone layer is very important for Earth as it protects us from harmful UV radiations of the Sun.
Ozone forms in the section of the atmosphere called the stratosphere. "The decreases in ozone are less than we saw at the poles before the Montreal Protocol was enacted, but UV radiation is more intense in these regions and more people live there", Joanna Haigh from Imperial College London, a coauthor on the study, said in another statement. The Montreal Protocol agreement of 1987 led to the phasing out of CFCs and the first signs of fix in the upper stratosphere over the Antarctic.
There, the scientists found a relatively small but hard-to-explain decline of ozone in the lower part of the stratosphere, the layer of the atmosphere that extends from about 6 miles to 31 miles above the planet's surface, since the year 1998.More news: Astros reach 2-year deal with World Series MVP Springer
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For some unknown reasons, Earth's ozone shield keeps depleting in some other parts of the lower stratosphere. Or, it could be a result of climate change, which has been exacerbated by human activity, and the changes it is causing to atmospheric circulation. The research was published in Atmospheric Chemistry and Physics on Tuesday.
Prof Joanna Haigh, worldwide research team member and Co-Director at the Grantham Institute for Climate Change and the Environment of Imperial College London said in a statement that, "The study is in lower to mid-latitudes, where the sunshine is more intense, so that is not a good signal for skin cancer".
"The finding of declining low-latitude ozone is surprising since our current best atmospheric circulation models do not predict this effect", said William Ball, the leader of the analysis.
Although the exact cause of this thinning of the ozone layer at the lower latitudes could not be decoded, the scientists are suspecting that climate change might be obstructing the ozone layer to heal.
There's also a possibility that a new class of chlorine-containing chemicals not limited by the Montreal Protocol, dubbed "very short-lived substances", could be contributing to the problem.
VSLSs include chemicals used as solvents, paint strippers, and as degreasing agents.