MIT researchers warn feedstock loophole in Montreal Protocol could delay ozone recovery by seven years

New research shows that leaked feedstock chemicals could delay the ozone layer's recovery by 7 years, necessitating a fix to the Montreal Protocol.

By: AXL Media

Published: Apr 16, 2026, 7:55 AM EDT

Source: Information for this report was sourced from Massachusetts Institute of Technology

The Emergence of a Hidden Environmental Threat

Scientists at the Massachusetts Institute of Technology have identified a significant "bug in the system" of the Montreal Protocol that may significantly impede the healing of the Earth's ozone layer. Despite the treaty's success in eliminating chlorofluorocarbons from aerosols and refrigeration, a regulatory loophole allows the continued use of ozone-depleting substances as "feedstocks" to manufacture other materials like plastics and nonstick chemicals. Susan Solomon, a professor of environmental studies and chemistry at MIT, explains that while production of these chemicals has nearly ceased for consumer use, their industrial application as raw materials remains a persistent source of atmospheric contamination.

Revised Leakage Estimates Challenge Old Assumptions

The initial decision to exempt feedstock chemicals was based on the assumption that only 0.5 percent of the substances would escape into the atmosphere during industrial processes. However, modern monitoring by the Advanced Global Atmospheric Gases Experiment (AGAGE) network has revealed that actual leakage rates are substantially higher, averaging approximately 3.6 percent for most chemicals. According to researcher Luke Western, the original belief was that companies would naturally prevent leaks to protect their profit margins, but atmospheric data now confirms that these industrial emissions are far more prevalent than the international community previously estimated.

Projecting the Impact on Stratospheric Healing

The international research team, which included experts from Switzerland and the United Kingdom, used the higher 3.6 percent leakage rate to model the long-term impact on the stratosphere. Their analysis, published in the journal Nature Communications, indicates that if current industrial practices continue, total emissions will level off around 2045 rather than continuing to decline. Under the current baseline of high leakage, the ozone layer is not expected to return to its healthy 1980 state until the year 2073. This represents a seven-year delay compared to a scenario where feedstock emissions are entirely eliminated, which would see a recovery by 2065.