Is ozone depletion still a concern? Which are the synergies of climate change?
On Wednesday, September 17, 2025, the ACG Center of Excellence in Sustainability hosted a special lecture to mark World Ozone Day. The event explored the state of the ozone layer and the urgent challenges posed by ozone depletion.
Drawing on over fifteen years of research, the keynote speaker, Assistant Professor Dr Ioannis Christodoulakis of Deree-The American College of Greece and Fellow of the Center of Excellence in Sustainability, delivered an engaging presentation and shared insights from his work monitoring stratospheric ozone through ground-based instruments and satellite data.
Dr. Christodoulakis provided the audience with all the necessary information regarding the role of the ozone layer as our planet’s protective shield, filtering out harmful ultraviolet radiation that causes skin cancer, cataracts, and DNA damage in organisms. Since the 1987 Montreal Protocol, global ozone recovery has been underway, but Dr. Christodoulakis reminded the audience that two rare Northern Hemisphere ozone holes underlying that recovery are not guaranteed.
In spring 2020, an unusually strong polar vortex over the Arctic trapped frigid air and formed polar stratospheric clouds that catalyzed rapid ozone loss, creating ozone values below 220 Dobson Units across extensive regions—an Arctic record since observations began.
In early 2025, sustained cold conditions and a stable polar vortex drove daily total ozone columns down to 214 Dobson Units on 17 February, breaching the 220 DU threshold that usually defines an ozone hole in the Antarctic and signaling a near‐hole event in the north.
After explaining this complex phenomenon, the ozone scientist, Dr. Christodoulakis, answered the audience’s valuable questions.
The event is connected to and promotes the 17 UN Sustainable Development Goals and is part of the relevant ‘Campus as a Living Lab’ taking place at the ACG under the Erasmus+ Project SDG4U.
