Professor Qing-Bin Lu from Canada’s University of Waterloo discovered that there is a large ozone hole in the tropical regions of our planet. According to findings so far, it could affect 50% of the world’s population, he said in a press release on the EurekAlert website. It should be noted that the use of different data analysis methods led to these findings.

The tropical ozone hole is seven times larger than the Antarctic ozone hole, and according to scientists, this has been happening in tropical areas since the 1980s. The hole is defined as an area with ozone depletion of more than 25% compared to the undisturbed atmosphere in the lower stratosphere, and its depth is comparable to the famous Antarctic spring hole.

Should we worry about another ozone hole?

“Tropical regions cover half the earth’s surface and are home to about half the world’s population,” Lu warned. “Existence of Tropical Ozone Hole May Cause Major Global Concern.” According to him, tropical and polar ozone holes play an important role in cooling and regulating stratospheric temperatures, reflecting the emergence of three “temperature holes” in the global stratosphere. These findings may prove to be the key to a better understanding of global climate change.

Depletion of the ozone layer can cause an increase in the amount of UV radiation falls to the earth’s surface. It increases the risk of skin cancer and cataracts, can weaken the human immune system, reduces agricultural production and negatively impacts organisms and sensitive aquatic ecosystems.

Ozone is a highly reactive gas molecule consisting of three oxygen atoms. According to the US Environmental Protection Agency (EPA), it forms in the stratosphere or in the upper layers of the Earth’s atmosphere when sunlight reacts with oxygen. Because ozone is highly reactive, it is constantly created and destroyed in the stratosphere, but its total amount is relatively stable over the long term across seasons and latitudes.

Lu’s discovery of the ozone hole was for his colleagues in the scientific community big surprise, because it is not predicted by general photochemical models. However, the data he discovered fully agreed with the model of electron reactions caused by cosmic rays and clearly showed that the Antarctic and tropical ozone holes had identical physical mechanisms.

Chemistry is to blame, restrictions don’t help much

Like the polar ozone hole, the central part of the tropical ozone hole has been shown to lose about 80% of its ozone. Preliminary reports indicate that levels of ozone depletion in equatorial regions threaten many people, and that the amount of UV radiation reaching the region is much greater than expected.

In the mid-1970s, atmospheric studies showed that the ozone layer, which absorbs most of the sun’s ultraviolet radiation, may be damaged by industrial chemicals, mainly chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), tetrachloromethane and methyl chloroform. The discovery of the ozone hole in Antarctica in 1985 confirmed that the cause of the damage was CFCs.

The process of creating and destroying ozone in the atmosphere is still ongoing, but the presence of certain chemicals can accelerate this destruction. One chlorine atom in the stratosphere can destroy up to 100,000 molecules, greatly reducing ozone levels. Although bans on the use of these chemicals have helped slow the process, evidence shows that ozone depletion continues.

“The current findings require further study of ozone depletion, changes in UV radiation, increased risk of cancer and other negative impacts on health and ecosystems in tropical regions,” stated Lu in his work.