Article image

Decline in ozone-depleting chemicals is an encouraging trend 

A new study led by the University of Bristol has reported significant advancements in reducing atmospheric levels of ozone-depleting chemicals, confirming the success of historic regulations. 

Particularly, the experts found a notable decline in hydrochlorofluorocarbons (HCFCs), which are both harmful to the ozone layer and potent greenhouse gasses.

Limiting the use of ozone-depleting chemicals 

The Montreal Protocol, established in 1987, played a critical role by limiting the production and use of ozone-depleting substances (ODS). Initially, HCFCs were introduced as replacements for the more harmful chlorofluorocarbons (CFCs). 

While the global production of CFCs has been banned since 2010, HCFCs are currently being phased out, with a target completion date of 2040.

“The results are very encouraging,” said lead author Luke Western, a postdoctoral fellow at the University of Bristol’s School of Chemistry. “They underscore the great importance of establishing and sticking to international protocols.” 

“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.”

Adopting ozone-friendly alternatives 

The study revealed that the total amount of ozone-depleting chlorine in all HCFCs peaked in 2021. This peak also marked the highest contribution of HCFCs to climate change, occurring five years earlier than predicted. Although the decrease in HCFC emissions between 2021 and 2023 was less than 1%, it indicates a positive trend.

“Their production is currently being phased out globally, with a completion date slated for 2040. In turn, these HCFCs are being replaced by non-ozone-depleting hydrofluorocarbons (HFCs) and other compounds. By enforcing strict controls and promoting the adoption of ozone-friendly alternatives, the protocol has successfully curbed the release and levels of HCFCs into the atmosphere,” Western explained.

Protecting the planet for future generations

The study relied on high-precision measurements from globally distributed atmospheric observatories, using data from the Advanced Global Atmospheric Gases Experiment (AGAGE) and the National Atmospheric and Oceanic Administration (NOAA). 

“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 the Swiss Federal Laboratories for Materials Science and Technology (EMPA).

“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,” said Isaac Vimont, a research fellow at NOAA.

Overall, the findings offer a hopeful outlook on the effectiveness of global protocols in reducing harmful emissions and addressing both ozone depletion and climate change. Continued vigilance and adherence to these protocols are necessary to ensure the full recovery of the ozone layer.

What is ozone depletion?

Ozone depletion refers to the gradual thinning of the Earth’s ozone layer in the stratosphere. This phenomenon is primarily caused by the release of ozone-depleting chemicals containing gaseous chlorine or bromine from industrial and consumer products. 

Contributing factors

The most significant contributors are chlorofluorocarbons (CFCs), halons, and other related substances. 

When these chemicals are released into the atmosphere, they eventually reach the stratosphere, where ultraviolet (UV) radiation breaks them down, releasing chlorine and bromine atoms. 

These atoms then react with ozone (O3) molecules, causing the ozone to break apart into oxygen molecules (O2) and single oxygen atoms, thus depleting the ozone layer.

Impacts of ozone depletion

The depletion of the ozone layer has significant environmental and health impacts. 

A thinner ozone layer allows more harmful UV-B radiation to reach the Earth’s surface, which can lead to an increase in skin cancers, cataracts, and other health issues. 

It also affects ecosystems, particularly marine life, as increased UV radiation can harm phytoplankton, the base of the marine food web.

The study is published in the journal Nature Climate Change.


Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

Check us out on EarthSnap, a free app brought to you by Eric Ralls and


News coming your way
The biggest news about our planet delivered to you each day