September 16 is observed every year as the International Day for the Preservation of the Ozone Layer, commonly known as World Ozone Day. In 2026, the day is being marked under the theme “Global Action for a Cooler Planet – Celebrating 10 Years of Sustainable Cooling under the Kigali Amendment to the Montreal Protocol.”
The United Nations General Assembly designated 16 September as World Ozone Day in 1994 to commemorate the signing of the Montreal Protocol on Substances that Deplete the Ozone Layer on 16 September 1987. The Montreal Protocol is widely regarded as one of the most successful environmental treaties in history. It has phased out nearly 99% of ozone-depleting substances and put the ozone layer on a path to recovery.
This year’s theme highlights the 10th anniversary of the Kigali Amendment (adopted in 2016). While the original Montreal Protocol targeted ozone-depleting chemicals, the Kigali Amendment expands its scope by driving the global phase-down of hydrofluorocarbons (HFCs) — potent greenhouse gases commonly used in refrigeration, air-conditioning, and other cooling applications.
HFCs do not deplete the ozone layer but have a high global warming potential. Fully implementing the Kigali Amendment could avoid up to 0.5°C of global warming by the end of the century, with even greater benefits when paired with energy-efficient cooling technologies.
World Ozone Day 2026 underscores the need for continued collective action — by governments, industries, and individuals — to accelerate the transition to safer alternatives, improve energy efficiency in cooling systems, and support innovation in the sector.
The day serves as a reminder that protecting the ozone layer and addressing climate change are interconnected goals that benefit people and the planet.