According to NASA, the hole in the ozone layer just shrank, and it hadn’t been that small since 1988. In fact, the ozone hole reached its peak on September 11, but then it got smaller through September and October. NASA also said that there was a decrease in the ozone depletion rate.
Though rare, sometimes there is good news when it comes to the environment. This time, the news is exceptional, and scientists hope the reduction of the ozone holes keeps on going. They said that the shrinking of the hole is due to an unstable and warmer Antarctic vortex which is the low-pressure stratospheric system that rotates in the atmosphere above the Antarctica.
The produced reactions are similar to those that found in the Arctic where the destruction of the ozone layer is far less accelerated.
“The Antarctic ozone hole was exceptionally weak this year,” said Paul A. Newman, chief scientist for Earth Sciences at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This is what we would expect to see given the weather conditions in the Antarctic stratosphere.”
The shrinking of the ozone hole is due to warmer-than-usual weather conditions
Little by little, the ozone hole was getting bigger due to toxic substances that were used and produced by humans. The implications of this phenomenon are certainly terrible and devastating for the wellbeing and the preservation of planet Earth and the different species that take part in it. On September 11, 2017, NASA published that the ozone hole reached its peak extent, covering about 7.6 million square miles.
This extent is similar to the size of the United States multiplied by 2 and a half. However, the good news is that thanks to a warmer-than-usual weather during the rest of September and during October, the ozone hole shrank, reaching its smaller extent since 1988, which is a remarkable thing.
Maybe scientists didn’t expect the hole to be reduced that much, but they did expect similar results. According to experts, warmer Antarctic vortex helps minimize polar stratospheric cloud formation in the lower stratosphere. The formation of these clouds is necessary because they lead to chemical reactions of the chlorine and bromine that deplete the ozone layer.
The depletion of ozone occurs every year, and it is accelerated in cold temperatures. Because of that, the peak extent of the ozone hole is usually reached in September when the winter in the southern hemisphere ends.
“Weather conditions over Antarctica were a bit weaker and led to warmer temperatures, which slowed down ozone loss,” said Paul A. Newman. “It’s like hurricanes. Some years there are fewer hurricanes that come onshore. . . this is a year in which the weather conditions led to better ozone [formation].”
Are actions to reduce climate change paying off?
Though this year’s maximum extent of the ozone hole was 2 and a half times the size of the United States, it was much smaller than last year’s peak when the hole was 1.3 million square miles bigger.
This might lead to think that global and national actions to reduce the ecological footprint and to reduce the effects of climate change are paying off. Maybe this could be an incentive to continue with these green initiatives worldwide.
The ozone hole was discovered by scientists about 30 years ago. Scientists noticed that chlorofluorocarbons weakened the ozone layer. People feared their skin and eyes would be damaged when being exposed to the sunlight or that they would develop skin cancer, but the foreseen consequences were so much worse including the devastation of forests, habitats, and species and the acceleration of natural disasters.
Because of the devastating consequences that the hole could have in the future generations, countries from all over the world signed the 1987 Montreal Protocol, which is a non-binding international agreement to unite efforts to reduce the ozone depletion by cutting off the chemical that accelerated this phenomenon.
“It’s extremely rewarding, because it was originally just a scientific effort, and then we were able to convince society that it was a problem — here’s what would happen if we do not deal with it,” said chemist Mario Molina, who had a key role in the discovery of the ozone hole decades ago. He was awarded a Nobel Prize for his efforts in 1995.
According to NASA — who is continuously tracking the evolution of the ozone layer — the ozone hole reached its broader extent in the year 2000. In 2014, The United Nations said that the partial recovery of the ozone layer was due to the reduction of chemicals used in air conditioners, refrigerators, and aerosol cans since the Montreal Protocol was enacted.
However, the toxic substances that deplete the ozone have long lifetimes, so they could be still producing harm in the atmosphere nowadays. Scientists expect the ozone layer to reduce to the size it had in 1988 by 2070.
Source: The Washington Post