Istanbul Technical University's Faculty of Aeronautics and Astronautics, Department of Meteorological Engineering, has issued a stark warning concerning the depletion of the ozone layer and its potential health consequences. This depletion, driven by various factors, including human activities and a recent volcanic eruption, may persist over the coming winters.
Scientists have been expressing concerns about the depletion of the ozone layer since the late 1970s. Notably, in 1985, scientists Jonathan Shanklin, Brian Gardiner and Joe Farman made a significant discovery related to the ozone layer in Antarctica. Two years later, in 1987, world leaders gathered to sign the "Montreal Protocol on Substances that Deplete the Ozone Layer." This historic agreement aimed to ban the worldwide use of chlorofluorocarbons (CFCs), chemicals known to cause ozone depletion. The protocol's signing date, Sept. 16, has been designated as the "International Day for the Protection of the Ozone Layer" since 1995, following a United Nations decision.
Professor Deniz Demirhan, a faculty member at Istanbul Technical University's Faculty of Aeronautics and Astronautics, highlighted the vital role of the ozone layer in protecting life on Earth. The ozone layer is a 3-millimeter-thick gas layer situated within the stratosphere, the second layer of Earth's atmosphere, extending to a thickness of 25-30 kilometers. This layer plays a crucial role in safeguarding ecosystems and human health by absorbing 99% of harmful ultraviolet (UV) rays from the sun.
Demirhan emphasized that the term "ozone depletion" is more accurate than "depletion of ozone gas" since the ozone layer itself is comprised of gas. He noted that the reduction in the total ozone level in the stratosphere since the late 1970s is primarily attributed to harmful gases emitted into the atmosphere as a result of human activities.
"These gases were used in products that have a very important place in our lives, such as refrigerators, coolers and fire extinguishers. These harmful gases can persist for years, even decades in the atmospheric layer known as the troposphere, which is closest to where we live and breathe," Demirhan explained.
Demirhan further highlighted the severe health implications of ozone layer depletion, including an increased risk of skin diseases, DNA damage, sunburns, cataracts, premature aging and weakened immune systems due to direct exposure to harmful UV rays from the sun.
The impact of ozone depletion extends beyond human health. Marine ecosystems, particularly plankton, are vulnerable to damage from harmful UV rays, disrupting the aquatic food chain. Additionally, plants exposed to intense UV rays may experience slower growth, delayed blossoming and photosynthesis disruptions.
While human activities have contributed significantly to ozone layer depletion, volcanic eruptions exacerbate the issue. Large volcanic eruptions release sulfur dioxide into the stratosphere, where it reacts with chlorine from human-generated harmful gases, accelerating the destruction of ozone.
Demirhan emphasized that the ozone layer's thickness varies seasonally and geographically. Ozone levels begin to rise in July with warming weather and decline in November as temperatures cool. The most pronounced ozone depletion occurs at the poles, with the South Pole experiencing a slightly greater decrease than the North Pole.
In a concerning development, the eruption of the Hunga Tonga volcano in January 2022, the most significant volcanic eruption in a century, injected ice and water vapor deep into the stratosphere. This event raised water vapor levels by 5%-10% and blocked sunlight from reaching Earth, leading to stratospheric cooling over the Southern Hemisphere. Excess water vapor has contributed to ozone depletion in the Southern Hemisphere, and this trend is expected to continue over the next few winters.
