The world observes the International Day for the Preservation of the Ozone Layer on September 16. The theme this year is "From science to global action."

The United Nations General Assembly proclaimed this day in 1994 to commemorate the Montreal Protocol signed in 1987. According to data from the United Nations Environment Programme, emissions of ozone-depleting substances (ODS) have dropped by 99 percent since 1989, and the ozone layer is expected to recover to pre-1980 levels by mid-century in most regions, helping avoid about 0.5 degrees Celsius of warming by 2100.

The ozone layer, 15 to 50 kilometers above Earth, filters about 99 percent of harmful Ultraviolet-B radiation, protecting human health, crops and marine ecosystems.

The discovery of the Antarctic ozone hole in 1985 prompted decisive global action. While the hole still exists, the United States' National Oceanic and Atmospheric Administration reported that in 2024 it was the seventh smallest since recoveries began, showing clear signs of healing.

Since its accession to the Montreal Protocol in 1991, China has phased out 628,000 tonnes of ODS and adopted ambitious national measures (2025-2030) to phase down hydrofluorocarbons (HFCs), ban HFC-using refrigerators from 2026, and manage controlled substances' full life cycles.

It is a pioneer in adopting low-global-warming-potential refrigerants like R290, with millions of R290-air conditioners already produced.

At the recent International Day of Clean Air for Blue Skies, Martina Otto, head of the Secretariat for the UN Climate and Clean Air Coalition, praised China's decisive policies and green transition efforts as models of rapid progress. Tsinghua University experts also noted that future strategies should focus on "co-benefits," integrating air quality improvement with climate and ozone protection goals.

Individuals can help protect the ozone layer by choosing products free of Chlorofluorocarbons (CFC), maintaining air conditioners properly to reduce leaks, and recycling old appliances via certified channels.

From treaties to national policy to personal choices, each effort contributes to healing our sky and safeguarding the planet.

(Cover designed by CGTN's Li Wenyi)