Unprecedented Recovery: Ozone Layer Heals Ahead of Schedule

High-Altitude Integrated Carbon Observation System (ICOS) Jungfraujoch Station in Switzerland

The high-altitude Integrated Carbon Observation System (ICOS) Jungfraujoch station in Switzerland was one of the sampling stations used to take atmospheric measurements of hydrochlorofluorocarbons. Credit: Jungfrau.ch

Recent findings indicate significant reductions in hydrochlorofluorocarbons (HCFCs), harmful to both the ozone layer and climate. This success, stemming from the Montreal Protocol, shows that global efforts to phase out these substances are effective, with reductions exceeding earlier predictions.

A new study by an international team of researchers has revealed significant progress in the drive to reduce atmospheric levels of chemicals that destroy the Earth’s protective ozone layer, confirming the success of historic regulations limiting their production and use. Empa scientists contributed to this study with measurements from the high-alpine research station at Jungfraujoch.

Montreal Protocol and HCFCs

The study, led by researchers at the University of Bristol and published recently in Nature Climate Change, shows for the first time a notable decline in the atmospheric levels of potent ozone-depleting substances (ODS), called hydrochlorofluorocarbons (HCFCs). These HCFCs are also harmful greenhouse gases (GHGs), so their reduction should also lessen global warming.

“The results are very encouraging.” — Luke Western

Dusty star-for

The Montreal Protocol was agreed to internationally in 1987 to introduce controls on the production and use of ODS, which were once widely used in the manufacturing of hundreds of products, including refrigerators, aerosol sprays, foams, and packaging. HCFCs were developed as replacements for chlorofluorocarbons (CFCs). While production of CFCs has been banned globally since 2010, HCFC production and use are currently still being phased out globally, with a completion date slated for 2040. They will be replaced by non-ozone-depleting hydrofluorocarbons (HFCs) and other compounds.

Ozone-Depleting CFCs Chart

For Empa scientist and co-author Stefan Reimann, the study represents a “milestone in the history of measures to contain the ozone hole, in which we were able to show for the first time that even the replacement products for the even more ozone-depleting CFCs are now decreasing – and this even five years earlier than expected.” Credit: EMPA

“The results are very encouraging. They underscore the great importance of establishing and sticking to international protocols,” says lead author Luke Western from the University of Bristol’s School of Chemistry. “Without the Montreal Protocol, this success would not have been possible. So it’s a resounding endorsement of multilateral commitments to combat stratospheric ozone depletion, with additional benefits in tackling human-induced climate change.”

Decline Faster Than Anticipated

The international study shows the total amount of ozone-depleting chlorine contained in all HCFCs combined peaked in 2021. Because these compounds are also potent GHGs, their contribution to climate change also peaked in that year. This maximum occurred five years earlier than predicted in the last ozone assessment report published in 2022. Although the drop between 2021 and 2023 was less than 1%, it still shows HCFC emissions are heading in the right direction.

For Empa scientist and co-author Stefan Reimann, the study represents a “milestone in the history of measures to contain the ozone hole, in which we were able to show for the first time that even the replacement products for the even more ozone-depleting CFCs are now decreasing – and this even five years earlier than expected.” According to the Empa researcher, this was only possible thanks to the continuous tightening of international protocols and their verification with the help of atmospheric measurements, for instance on Jungfraujoch.

Ensuring Future Environmental Stability

The results rely on high-precision measurements at globally distributed atmospheric observatories, using data from the Advanced Global Atmospheric Gases Experiment (AGAGE) and the National Atmospheric and Oceanic Administration (NOAA) in the US, including the high-alpine research station on Jungfraujoch, where Empa scientists carried out their atmospheric measurements.

“We use highly sensitive measurement techniques and thorough protocols to ensure the reliability of these observations,” said co-author Martin Vollmer, an atmospheric scientist at Empa.

Co-author and NOAA scientist Isaac Vimont added: “This study highlights the critical need to be vigilant and proactive in our environmental monitoring, ensuring other controlled ozone-depleting and greenhouse gases follow a similar trend, which will help to protect the planet for future generations.”

For more on this research, see Scientific Insights Into a Key Environmental Victory.

Reference: “A decrease in radiative forcing and equivalent effective chlorine from hydrochlorofluorocarbons” by Luke M. Western, John S. Daniel, Martin K. Vollmer, Scott Clingan, Molly Crotwell, Paul J. Fraser, Anita L. Ganesan, Brad Hall, Christina M. Harth, Paul B. Krummel, Jens Mühle, Simon O’Doherty, Peter K. Salameh, Kieran M. Stanley, Stefan Reimann, Isaac Vimont, Dickon Young, Matt Rigby, Ray F. Weiss, Ronald G. Prinn and Stephen A. Montzka, 11 June 2024, Nature Climate Change.
DOI: 10.1038/s41558-024-02038-7

10 Comments on "Unprecedented Recovery: Ozone Layer Heals Ahead of Schedule"

  1. Clyde Spencer | July 6, 2024 at 8:29 am | Reply

    While there may well be an unexpected decline in HCFCs, the real concern is ozone. (Actually, the real concern is surface UV flux; however, that is another story.) If one goes to this website — https://ozonewatch.gsfc.nasa.gov/ — and scrolls down near the bottom, on the left side is a pair of graphs labeled “Annual Records.” It is evident that there isn’t much difference in recent years in the size or ‘depth’ of the Antarctic “Ozone Hole” from what it was in the 1990s, shortly after the Montreal Protocol was agreed to. It appears to me that the average Spring temperature, and strength of the circumpolar vortex, are more important than anthropogenic HCFCs! It appears that the ozone situation has been essentially stable since about 1994, except for anomalous spikes in 2002 and 2019 when the circumpolar vortex was weak when it was unusually warm in the Antarctic. If anything, there has been an increase in the size of the ‘hole’ over the last 4 years.

    This is not the first time that someone has claimed that the “Ozone Hole” is healing. Unfortunately, the publicly available evidence does not support the claim. Why would someone make a claim that can’t be backed up with obvious evidence? Scientists shouldn’t engage in wishful thinking.

    • Michael Wallace | July 6, 2024 at 3:44 pm | Reply

      I can’t find a hole of any kind in the data, but there does seem to be solar forcing, which in my view should be the null hypothesis against which cfc stokers should have to prove against.

      • Clyde Spencer | July 6, 2024 at 6:31 pm | Reply

        The so-called “ozone hole” is really a misnomer that has been popularized by the main stream media. Liberals have a penchant for assigning scary terms, like “ocean acidification” and “global heating,” that impact emotions more than simple descriptive terms like “lowering pH” and “warming trend.”

  2. Clyde Spencer | July 6, 2024 at 8:37 am | Reply

    “Although the drop between 2021 and 2023 was less than 1%, it still shows HCFC emissions are heading in the right direction.”

    What is the annual variance in HCFC emissions? Is 1% larger than the confidence interval? What is the margin of error for the measurements? Mathematics has been called the “language of science.” Yet, there seems to be more waving of arms than movement of lips.

  3. Ralph Johnson | July 8, 2024 at 6:41 am | Reply

    Sorry I’m going to get a little political here. If Don Trump gets elected this will change also his march against ecology is going to reverse all that is of any efforts to help our ecosystem.

    • Clyde Spencer | July 8, 2024 at 8:56 am | Reply

      You are not only getting “political,” you are getting psychic. You are claiming to know what the future holds and what another person is thinking and planning. How is your track record on forecasting the future? Are you a billionaire? If not, why should we trust a simple claim based on what you think will happen?

      BTW, “ecology” means the study of ecosystems. Are you also suggesting that Trump has something against studying ecosystems?

      • Yes because Trump never used news that he would often distort to his own needs in order to fuel his own agenda. This is what I was afraid, Trump supporters coming out of the woodwork and spreading misinformation.

  4. Honestly, why would you publish this. This is just going to allow trump supporters and similar to fuel their conspiracy agenda about how climate change is a hoax. These guys can’t tell the difference between ozone and pollution.
    I can already see campaigns supporting coal and oil coming in.

    • Clyde Spencer | July 13, 2024 at 10:44 am | Reply

      You appear to share some things in common with Ralph Johnson. Although, your remark about “these guys” adds generalization to his psychic abilities. What makes you think that “trump supporters,” which is a political attribute, are the only ones who question the claims about the climate?

      Incidentally, one of the important distinctions between ozone and pollution is the altitude at which the ozone resides. Are you aware of that?

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