A study published earlier this year pointed to a decrease in the size of the ozone hole over the Antarctic.
This healing process indicates the success of the Montreal Protocol, the 1989 treaty intended to limit the production and use of ozone-harming chemicals.
Ratified by all United Nations Members, as well as Niue, the Cook Islands, the Holy See and the European Union, it’s been hailed as “perhaps the single most successful international agreement to date.” (Kofi Annan)

Ten Circles – magnolia leaf crotched with cotton yarn
Artist: Susanna Bauer
It’s worth noting that the movement to reduce the production and use of gases that affect the ozone layer came long before ‘scientific consensus’ was actually reached.
Like the discussion surrounding carbon emissions and climate change, scientists who argued for a reduction in chlorofluorocarbon (CFC) production and use (mainly for refrigeration purposes and aerosol spray propellant) faced an array of opposition.

One, Two, Three
Artist: Susanna Bauer
DuPont held the patent for Freon, a CFC widely used around the world, but one which was losing profitability. The company put up aggressive arguments against any regulation of CFC production for several years – while searching for replacement alternatives.
The publication of ozone hole images in the 1980s focused public attention on the issue, just around the time DuPont felt it had found viable gas alternatives and the Freon patent had expired.
DuPont switched course, became an active supporter of CFC limitation and a strong proponent of international action. It also earned itself a reputation as a company concerned with the environmental impact of its products. (It bears mentioning that most of the alternative products also count as harmful greenhouse gases with varying levels of atmospheric toxicity.)

Common Ground (II)
Artist: Susanna Bauer
The Montreal Protocal was the result of a rare confluence of public opinion, environmental interests and corporate action. Corporate and government reluctance to limit CFC production was otherwise similar to today’s climate change discussion.
In the end, it always seems to come down to habits, inertia and money (or lack thereof) on the one side, and an amassing of scientific proof and activism on the other.

Moon (II)
Artist: Susanna Bauer
Perhaps what the Montreal Protocol really had going for it was the image of the hole in the atmosphere, a singular lens that could focus attention, fears, research and opinion.
It’s profoundly encouraging that the positive effects of an international treaty on a large-scale environmental challenge can be measured in a relatively short span of time.
Here’s hoping this visible progress can impact the usual cost-benefit conversations when it comes to climate change negotiations.

Images of the Antarctic ozone hole. If current trends continue, the hole is expected to close by 2040.
Images/graphic: NASA Goddard Space Flight Center/ Business Insider