Science

Earth’s Ozone Shield Keeps Depleting

Even though we were thrilled with the information that the hole in the ozone layer has been showing signs of healing and appears to be smaller than ever, the Earth’s Ozone shield continues to deplete in other places around the world, according to the scientists. The decline of the ozone shield is located above some of the most populated places on our planet. Furthermore, the depletion of Earth’s ozone shield could result in even more damage than the hole located above the Antarctic.

Earth's Ozone Shield
skeeze / Pixabay

The ozone layer forms in a section of the atmosphere which is called the stratosphere. The ozone layer blocks deadly UV radiation coming from the sun, and in that way it protects plants, animals, and humans from receiving high levels of UV radiation which can damage them and jeopardize their health.

During the 1980’s scientists discovered that a large hole had formed in the ozone layer, and exposed the Antarctic to much higher levels of the radiation compared to the other locations on Earth. Scientists blamed aerosols and refrigerants for the formation of the ozone hole, as they release ozone-depleting substances such as chlorofluorocarbons, better known as CFCs.

The Montreal Protocol agreement

The continuous depletion of Earth’s Ozone Shield led scientists to sign the Montreal Protocol agreement in 1987. That led to governments phasing out the CFCs, which led to the first results of healing of the ozone shield above the Antarctic.

Still not known why?

For some unknown reasons, Earth’s ozone shield keeps depleting in some other parts of the lower stratosphere. Researchers revealed their findings in a study published in Atmospheric Chemistry and Physics. Researchers determined that the affected area spreads from latitude 60N which is the line that goes through Canada and Russia, down to 60S which is above Antarctica.

“The potential for harm in lower latitudes may actually be worse than at the poles. 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 people live there,” Joanna Haigh, study co-author, co-director of the Grantham Institute for Climate Change and the Environment at Imperial College, London, said in a statement.

Researchers conducted an analysis on 11 different locations and gathered information which helped them create a subtle model of the ozone throughout the last 30 years. They discovered that the amount of ozone in the lower stratosphere was still decreasing.

The scientists were surprised by the results that defied the expectations of the already existing models. William Ball from ETH Zurich and PMOD/WRC Davos, who led the analysis said in a statement: “The finding of declining low-latitude ozone is surprising, since our current best atmospheric circulation models do not predict this effect. Very short-lived substances could be the missing factor in these models.”

The chemicals that are used as solvents, including paint strippers and degreasing agents could be the reason behind Earth’s ozone shield depleting. One of such chemicals is actually used to create a CFC replacement.

Also, scientists suggested that climate changes could be responsible for these changes in the ozone layer as well.