World Ozone Day 2025 – Is ozone depletion still a concern? Which are the synergies with climate change? Join to find out!

When: Wednesday, September 17, 2025 | 14:30-15:20
Where: AC Auditorium

Organized by: ACG Center of Excellence in Sustainability

About the event

You are invited to a fascinating lecture on environmental issue of ozone layer depletion.

Join us on Wednesday, 17 September 2025, at 14:30 in the AC Auditorium for a keynote speech on the health of the ozone layer and the urgent challenges of ozone depletion.

Earth’s stratospheric ozone acts as our planet’s sunscreen, filtering out high‐energy ultraviolet light that causes skin cancer, cataracts, and DNA damage in organisms. Since the 1987 Montreal Protocol, global ozone recovery has been underway, but two rare Northern Hemisphere ozone hole events remind us that recovery is 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.

The ozone scientist, Assistant Professor Ioannis Christodoulakis, The American College of Greece Deree – ACG and Fellow of the Center of Excellence in Sustainability – ACG, will explain the phenomenon and provide us with all necessary answers

About the speaker 

Assistant Professor Ioannis Christodoulakis has devoted more than fifteen years to investigating the ozone layer. He specializes in monitoring stratospheric ozone through prototype ground-based instruments and conducting ozonesonde launches to obtain vertical profiles of ozone alongside complementary atmospheric parameters. By combining these in-situ measurements with concurrent satellite observations, he achieves deeper, analytically driven insights into ozone dynamics.

Dr. Christodoulakis has authored over thirty peer-reviewed papers, delivered more than forty-five presentations at international and national conferences, and published one textbook. Beyond ozone research, his work encompasses the study of air pollution’s effects on cultural heritage, remote sensing applications, paleoclimate reconstruction and climate dynamics, long-term climate evolution, and luminescence dating techniques.