The discovery of a "giant" hole in the ozone layer threatens half of the Earth's population
Scientists at the Canadian University of Waterloo have discovered a "giant" hole in the ozone layer above most parts of the Earth's equatorial region.
The hole appears throughout the year, and is seven times larger than the hole over Antarctica that appears in the spring of each year.
Professor King Bin Lu told the British newspaper, The Independent , that his research indicates that the hole has been around for 30 years, and covers a huge area that may affect half of the Earth's population.
He added, "Unlike the Antarctic ozone hole, which appears only during the spring, the hole in the equatorial region has been present during the entire seasons since the 1980s, and the area it covers is approximately seven times larger."
He stressed that the hole may cause global concern, in particular, with its potential to raise ultraviolet radiation waves on Earth, and the subsequent skin cancer, cataracts and other negative effects on health and ecosystems in tropical regions.
He said that there are "preliminary reports showing that levels of ozone depletion over the tropics are already threatening large numbers of their populations, and that the associated ultraviolet radiation reaching the regions was much greater than expected."
Why was the discovery of this hole delayed?
The professor acknowledges that "it may seem inconceivable that the large tropical ozone hole has not been discovered before, but there are some fundamental challenges in making this discovery."
“First, a tropical ozone hole was not expected using prevailing photochemical theory. Second, unlike the seasonal Antarctic/Arctic ozone holes that appear mainly in the spring, the tropical ozone hole does not change fundamentally across seasons, thus It is not visible in the original observed data."
As happens in the Antarctic hole, the new hole showed an 80 percent depletion of ozone in its center, according to the research published in the scientific journal " AIP ".
The research also sheds light on the differences between the prevailing theories about the causes of ozone depletion.
Previously, it was believed that the presence of chlorofluorocarbons (CFCs) resulting from chemical manufacturing was the biggest cause of ozone depletion, and the newspaper reported that since the launch of the Montreal Protocol in 1987, banning the use of the materials it produces has had a significant impact on reducing their global use.
But despite the ban, the study says that large, deeper core holes in the ozone layer were detected in the late 2000s and between 2020 and 2021.
"This was not expected from any model based on the theory of photochemistry and climate," the professor added.
Professor Lu and his colleagues had presented another theory 20 years ago, known as the "cosmic ray-driven electron interaction" or (CRE) for short.
"The recorded results strongly indicate that both Antarctic and tropical ozone holes were formed by a single mechanism, and the CRE mechanism showed excellent agreement with the documented data," he said.
At the same time, the professor emphasized that "chlorofluorocarbons, without a doubt, are the main cause of ozone depletion, but cosmic lusts play a major catalytic role in causing ozone deposits in the poles and the equatorial region."
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