Why don’t the greenhouse gases escape through the Ozone Hole?

Can we blame him for the confusion?
Can we blame him for the confusion?

Don’t laugh. The perception of the TV viewer in this cartoon (which first appeared a couple of years ago in the Akron Beacon Journal in Ohio, United States) is more common that you’d think. In recent years, as climate change rose up in the media’s news agenda and the public’s list of concerns, I have met a number of people – from across educational and cultural spectra – who harbour similar confusion about the two issues.

I showed this cartoon, and referred to the wide-spread confusion, in my opening remarks to the Ozone Media Roundtable, an event to engage Asian media professionals on the nexus between ozone depletion and climate change. The meeting, held in Chiang Mai, Thailand, on 8 – 9 October 2009, was organised jointly by the United Nations Environment Programme (UNEP) and TVE Asia Pacific for invited senior journalists and broadcasters from the Asia Pacific region.

Ozone layer depletion and climate change are linked in a number of ways, but ozone depletion is not a direct or major cause of climate change.

In fact, the relationship between ozone and climate is both complex and nuanced, which has prompted some experts to call it a ‘Tango in the Atmosphere’. Ozone affects climate, and climate affects ozone. The authoritative UNEP GRID Arendal website says: “Ozone depletion and climate change are two distinct problems but as they both modify global cycles, they cannot be totally separated. There are still many uncertainties concerning the relations between the two processes.”

Read more about this at the Ozone Hole website.

Since the late 1980s, Montreal Protocol on substances that deplete the ozone layer has successfully phased-out 97 per cent of 100 chemicals that damage the protective shield that filters out harmful ultra violet rays to the Earth.

In recent years, research has outlined that global efforts to protect the ozone layer has also delivered climate benefits as many of the chemicals that damage the ozone layer – such as chloroflurocarbons or CFCs – also cause global warming.

In 2007 a scientific paper calculated the climate mitigation benefits of the ozone treaty as totalling an equivalent of 135 billion tonnes of C02 since 1990 or a delay in global warming of seven to 12 years. That same year countries meeting in Canada, under the Montreal Protocol, agreed to an accelerated freeze and phase-out of Hydrochloroflurocarbons (HCFCs)—chemicals designed to replace the old, more ozone-damaging CFCs – in the main for the climate benefits.