Empa Led Research Highlights Rising Chemical Emissions Threatening Ozone Recovery Timeline

The Jungfraujoch high alpine research station is located at 3,580 meters above sea level on a mountain saddle in the central Swiss Alps. Image: Empa

(IN BRIEF) A study led by Empa has found that emissions from industrial feedstock chemicals could delay the recovery of the ozone layer by several years. These substances, still used in manufacturing processes, have been underestimated in both usage and emission levels, with leakage rates significantly higher than previously assumed. The research indicates that continued emissions could push full ozone recovery from around 2066 to approximately 2073. In addition to harming the ozone layer, these chemicals also contribute to climate change, highlighting the need for updated regulations and coordinated global action to reduce their impact.

(PRESS RELEASE) DÜBENDORF, 16-Apr-2026 — /EuropaWire/ — Empa has led an international study revealing that the recovery of the Earth’s ozone layer may be delayed by several years due to ongoing emissions of industrial feedstock chemicals. These substances, still widely used as raw materials in manufacturing processes, have largely remained outside the scope of international environmental agreements.

Although many ozone-depleting compounds such as chlorofluorocarbons and carbon tetrachloride were phased out of consumer applications decades ago, they continue to be used in industrial production, including in the manufacturing of modern refrigerants and plastics. Until now, their environmental impact has been underestimated, particularly in terms of how much escapes into the atmosphere during production and handling.

The research team found that between three and four percent of these feedstock chemicals leak into the atmosphere during manufacturing, transport, and processing—far exceeding earlier estimates of around 0.5 percent. In addition, their overall use has grown significantly in recent decades, driven by demand in industries such as refrigeration and advanced materials.

Stefan Reimann, atmospheric scientist at Empa and lead author of the study, explained that these substances not only contribute to ozone depletion but also act as potent greenhouse gases. Reducing their emissions would therefore provide dual benefits for both ozone layer recovery and climate protection.

The findings are based on extensive atmospheric measurements collected through global monitoring networks such as the Advanced Global Atmospheric Gases Experiment (AGAGE), which includes high-altitude observation stations like Jungfraujoch in the Swiss Alps. By analyzing long-term concentration trends of these chemicals, researchers were able to identify discrepancies between reported production data and actual atmospheric emissions.

The study highlights that emissions are increasing not only due to higher leakage rates but also because of rising global demand for feedstock chemicals. Since 2000, their use has grown by approximately 160 percent. Initially used to produce hydrofluorocarbons as substitutes for banned refrigerants, these chemicals are now also essential in producing newer alternatives such as hydrofluoroolefins, as well as in the polymer industry. Materials such as fluoropolymers used in products like non-stick coatings and lithium-ion batteries further contribute to growing demand.

Using various future scenarios, the researchers assessed the long-term impact on ozone layer recovery. Previous projections suggested that the ozone layer would return to its 1980 state around 2066. However, if current emission levels persist, recovery could be delayed by roughly seven years, potentially extending to around 2073, with some uncertainty in the estimate.

In addition to their impact on ozone depletion, these emissions could significantly affect the climate. By mid-century, emissions from feedstock chemicals could reach levels equivalent to around 300 million metric tons of carbon dioxide annually, comparable to the emissions of major European countries.

The study underscores the need to reassess current regulatory frameworks, including the Montreal Protocol, which has been widely regarded as a successful global agreement to protect the ozone layer. While the treaty addressed many ozone-depleting substances, feedstock chemicals were largely exempt due to earlier assumptions about minimal emissions.

Researchers emphasize that addressing this issue will require renewed collaboration between science, policymakers, and industry to update regulations and reduce emissions. By doing so, it may be possible to mitigate further delays in ozone recovery while also contributing to broader climate goals.

SOURCE: EMPA