Earth's Ozone Layer Has Been Healing Since 33 Years: Why It Matters In Climate Change Fight

About 33 years ago, the Montreal Protocol came into effect in 1987, where the world pledged to cease the harm it was causing to the ozone layer through CFCs. CFC gases were commonly used in refrigeration equipment, air conditioning devices as well as certain kinds of aerosol sprays. And while several countries have pledged to stop the use of such gases, switching to non-harmful alternatives, not all countries are doing so.

In 2017, reports revealed that that chemicals widely used for paint stripping and manufacturing PVC, are in fact, not decaying before reaching our upper atmosphere, as previously thought. These ¡°very short-lived substances¡± are doing more damage than we realise.?

One of these chemicals, Dichloromethane, is used as an industrial solvent and a paint remover, whereas the other, dichloroethane, is used in construction, agriculture and to manufacture PVC.?

Researchers claim that levels of these chemicals (mostly made in China) have increased by 60 percent over the past 10 years, and it could take our ozone layer 30 additional years to repair.

Satellite measurements from 2017 show that the hole in the Earth¡¯s Ozone layer that forms over the Arctic each September was the smallest it had ever been. According to scientists from NASA and the NOAA (National Oceanic and Atmospheric Administration), the ozone hole was smaller than every other observation since 1988.

NASA says the hole in 2017 reached its largest width on September 11, stretching over an area two and a half times the size of the US, and then shrank through the rest of that month and the next. We¡¯ve also had the least amount of ozone deplete this year in the last 30 years.

In February of 2018, researchers discovered unexpected decreases in the lower part of the stratospheric ozone layer, offsetting the recovery in ozone that we had expected to see.?

While we did see the ozone layer heal, it was the outer layer. That hasn¡¯t been the same for the ozone layer over lower latitudes, where humans live. In fact, they found that these areas showed a small decline in ozone levels in the lower stratosphere since 1998. The upper stratosphere, meanwhile, has continued to recover.

In October of 2019, we witnessed the smallest ozone hole over Antarctica, signalling that we are on the right track to healing the ozone layer.?

As per NASA and the NOAA (National Oceanic and Atmospheric Administration) the ozone hole over Antarctica reached its peak of 6.3-million square miles on September 8 and shrank all the way to 3.9-million square miles during the remainder of September and October.

In March 2020, scientists observe that the ozone layer over Antarctica has recovered to the point that several atmospheric changes in the Earth¡¯s southern hemisphere have come to a halt.?

Researchers indicate that the check on ODS (ozone-depleting substances) production had a hand in stopping this shift of jet streams to further south of the planet. Using simulations, the researchers have managed to show a distinctive relation between the Montreal Protocol and the migration of the jet stream.

While we were celebrating healing of the ozone layer, scientists discovered a million-kilometre gap in the North pole. A hole is commonly seen over the Antarctic -- which is to the south pole. However, in March this year, we saw one in the North too.

This was spotted by Scientists from the German Aerospace Centre, looking at the data from Copernicus Sentinel-5P satellite. They noticed unusually strong depletion of ozone layer over the northern polar region.

Last week, scientists discovered that the million-kilometre ozone layer hole over the Arctic had been healed. The healing of the hole in the Earth¡¯s ozone layer is not due to the reduction in pollution due to COVID-19 lockdown. Instead, it is because of the polar vortex - high-altitude currents bringing cold air to the polar regions.?

Copernicus ECMWF explains that the polar vortex experienced this year was extremely powerful, with very cold temperatures inside it. This further resulted in the generation of stratospheric clouds that destroyed the ozone layer by reacting with CFC gases.

With the polar vortex weakening, the ozone layer will roll back to its normal state in the polar region. Copernicus ECMWF predicts that it will form again, but it would not affect the ozone layer as much the next time.