Projects, events and news from the University of Cambridge Museums
So often the environmental headlines in the news discuss the lack of international agreement on climate change, unprecedented global warming and drops in renewable energy tariffs. From such headlines you would not know that the environment is full of success stories, more commonly of individual groups and organisations doing their bit, but also on an international stage as well.
Some of you may not be aware that as well as 2015 marking the 30th anniversary of the film classic ‘Back to the Future’, it also marks the 30th anniversary of the discovery of the hole in the ozone layer.
On 16 September we, for once, got to celebrate a success in environmental science and policy on International Day for the Preservation of the Ozone Layer, with the event The Ozone Hole Discovery – 30 years on.
Meet Jonathan Shanklin, retired Head of the Meteorology and Ozone Monitoring Unit for the British Antarctic Survey, conservationist and bell ringer. He is one of the trio which in the 1980s discovered the ozone hole who will be telling us all about the historic discovery, the quick actions of the international community and the future we can enjoy because of it. He will be joined by Professor John Pyle, who is the newly appointed Head of the Department of Chemistry at the University of Cambridge and who has been heavily involved in the legislative process that has come out of the discovery.
So what is the ozone hole? It is very easy to get mixed up in all the many different terms such as global warming, greenhouse effect and ozone hole, which impact our environment. Well ozone is a chemical in our atmosphere that does different things at different levels. In the lower atmosphere, ‘the troposphere’, it acts as a greenhouse gas contributing to global warming. Yet in the next level up, ‘the stratosphere’ where planes fly, this chemical provides an incredibly important protective barrier for harmful UV rays coming from the sun that we refer to as the ozone layer.
The amount of ozone in the ozone layer varies at different times of year due to the chemical reactions that take place in the presence of sunlight but the destruction of ozone is then exacerbated by the presence of chlorine. Chlorine has many sources, but an increasingly large source to the atmosphere by the 1980s was chlorofluorocarbons (CFCs) used in refrigeration and air conditioning systems. Although these chemical reactions were known, it wasn’t until research was completed in 1984 that the impact of CFCs on ozone was felt, when a hole in the ozone layer over Antarctica was discovered which was much larger than anyone had imagined. It was originally thought that the low temperatures of the area would not allow for such a fast pace of chemical reaction to destroy ozone in large quantities. What was later discovered was that these ozone depleting reactions were taking place on the surface of the ice crystals on the clouds formed in the polar stratosphere, releasing active forms of CFCs, even at low temperatures.
By 1985 the research by Jonathan Shanklin and his colleagues on the newly discovered ozone hole had been published in the journal Nature. And most astoundingly for the pace of international politics, just two years later, after a series of rigorous meetings and negotiations, the Montreal Protocol on Substances that Deplete the Ozone Layer was agreed upon on 16 September 1987. The Montreal Protocol stated that ozone depleting substances such as CFCs were to be phased out of use by 2000. It is now predicted that by 2080, Antarctic ozone will return to its 1950s levels.
So how is it that science and politics worked together so well to produce legislation that solved an environmental problem so fast, when issues such as international agreement on solutions to global warming are such a problem? The main thing to note is that the cause of the ozone hole was down to just a few substances that had a limited amount of applications such as refrigeration. Banning the use of a few substances is much more easily managed in comparison to one of the main causes of climate change, carbon dioxide, a chemical produced by many substances and sources. The second contributing factor was that replacement chemicals for CFCs were already being produced and better replacements are being developed all the time. So in this case, no lifestyle changes were necessary from the international community.
So there is still definitely much work ahead to get international cooperation on climate change as we lead up to the next international forum to discuss these issues at COP21 in Paris this December. But meanwhile we celebrate what has already been achieved on the International Day for the Preservation of the Ozone Layer, and the discovery that led to Dr Shanklin being awarded a Blue Peter badge for his discovery. What’s not to celebrate?
Rosie Amos, Education and Outreach, The Polar Museum