Ozone Hole Is Slowly Healing Thanks to the Montreal Protocol

It's proof that nations can work together and fix things.

Earth's Ozone
The Goddard Space Flight Center's satellites observed an 11.5 million square-mile hole, a severe thinning of Earth's protective ozone layer, over Antarctica in 2000.

Newsmakers / Getty Images

Earth’s protective ozone layer is slowly healing, a new United Nations-backed report says. It confirmed the phase-out of nearly 99% of banned ozone-depleting substances, in accordance with the Montreal Protocol, which led to the ozone layer's recovery—the shrinking of the ozone hole and reducing exposure to ultraviolet radiation. 

"That ozone recovery is on track according to the latest quadrennial report is fantastic news. The impact the Montreal Protocol has had on climate change mitigation cannot be overstressed. Over the last 35 years, the Protocol has become a true champion for the environment," said Meg Seki, executive secretary of the United Nations Environment Program's Ozone Secretariat, in a statement.

What Is the Montreal Protocol?

The Montreal Protocol is an international agreement designed to phase out the production and consumption of chemicals that deplete the ozone layer. Signed in 1987 and put into effect in 1989, the Montreal Protocol treaty stemmed from increased global concern about the harmful impact that chemicals such as chlorofluorocarbons (CFCs) were having on the planet's protective ozone layer.

But don't put away your sunscreen yet—this will take a while. According to the United Nations Environmental Program (UNEP), the ozone layer will recover to 1980 values before the hole appeared, by 2066 over the Antarctic, and by 2040 over the rest of the world if things keep going the way they have been. 

It's important to note the significance of the 1987 signing of the Montreal Protocol beyond regulating refrigerants and ozone-depleting chemicals, as it became the model for dealing with climate change. Spencer R. Weart described what happened after it was signed in his book, "The Discovery of Global Warming":

"The people who had begun to worry about global warming hoped that the precedent set by the Montreal Protocol could serve as an example for negotiations to restrict greenhouse gas emissions. Industrial groups and ideologues had vehemently opposed this sort of regulation as an insufferable economic drag."

A year later, in Toronto, the "World Conference on the Changing Atmosphere: Implications for Global Security," set the groundwork.

"The Toronto Conference's report concluded that the changes in the atmosphere due to human pollution 'represent a major threat to international security and are already having harmful consequences over many parts of the globe.' For the first time, a group of prestigious scientists called on the world's governments to set strict, specific targets for reducing greenhouse gas emissions. Immediate action was needed, they said, to negotiate an 'international framework convention' as a condition for national legislation. That was the Montreal Protocol model: set targets internationally, and let governments come up with their own policies to meet the targets."

This led directly to the establishment of the Intergovernmental Panel on Climate Change (IPCC). The reason that the IPCC has so much trouble coming to a consensus on issues is a function of its design. According to Weart:

"Its principal architect was the conservative Reagan administration. Required to issue rules and reports only with the firm agreement of essentially all the world's leading climate scientists plus the consensus of all participating governments without exception, the IPCC's constitution should have been (and perhaps was intended to be) a recipe for paralysis."

The results of the 2022 United Nations Climate Change Conference (COP27) demonstrate that former President Ronald Reagan got what he wanted; achieving consensus is proving difficult. But the Montreal Protocol proved it could be done—nations could agree on targets and comply with them.

It also demonstrated that agreements could evolve. The 2016 Kigali Amendment began the phase-out of hydrofluorocarbons (HFCs) that replaced the original chlorofluorocarbons (CFCs) that Montreal regulated, although it took until October 2022 for President Joe Biden to ratify it, after years of opposition from the right wing.



We are not out of the woods with climate or the ozone layer. R-22 refrigerants are still available, theoretically, for refilling older equipment only, but we reported earlier that levels of it are spiking. We are also at the start of a heat pump revolution, and according to construction engineering company BSRIA, "over 80% of heat pumps sold in 2019 contained the HFC R410A refrigerants, with R134A being the second most common."

The recent International Energy Agency report on heat pumps noted that leakage could be a problem. "Emissions of these gases, which are powerful GHGs, threaten to offset part of the climate benefits from switching away from fossil fuels for heating," stated the report.

But still, the quadrennial assessment report is something to cheer about. It shows that the Montreal Protocol was effective, that nations can work together, and that technology and innovation can help solve these problems.

The last word goes to the World Meteorological Organization's Secretary-General Petteri Taalas: "Ozone action sets a precedent for climate action. Our success in phasing out ozone-eating chemicals shows us what can and must be done—as a matter of urgency—to transition away from fossil fuels, reduce greenhouse gases and so limit temperature increase."

View Article Sources
  1. "Ozone layer recovery is on track, helping avoid global warming by 0.5˚C." UN Environment Programme. 9 Jan. 2023. Press release.

  2. Gallagher, Katherine. "Montreal Protocol: Have Efforts to Save the Ozone Layer Been Successful?" Treehugger.

  3. Weart, Spencer R. "The Discovery of Global Warming: Revised and Expanded Edition." Harvard University Press, 2008.

  4. "BSRIA's view on refrigerant trends in AC and heat pump segments." BSRIA News, Jan. 2020.