CFCs and the ozone hole

In the 1940s a number of new, synthetic chemicals were invented as non-toxic and non-flammable gases for use in refrigeration, aerosol sprays and in foam and packaging manufacture. These chemicals, such as chlorofluorocarbons (CFCs) and related gases, became widely used around the world before research found that they had a negative effect on the ozone layer. The ozone layer is a naturally forming layer of gas in the Earth’s stratosphere, 15 to 30 kilometres above the surface, that protects life on Earth from excessive ultraviolet radiation—the most well-known consequence of which is skin cancer.

In 1985, the first scientific paper suggested a mechanism linking CFCs and a reduction in the density of the ozone layer during spring. The reduction was most noticeable at the south pole, where ozone concentrations were found at record lows. From the mid-1980s onwards a thinning, or hole, in the ozone layer formed over the Antarctic each September due to a combination of CFCs, low temperature, high altitude winds circling around the pole and the arrival of sunlight in spring. While the ozone breakdown is most noticeable in Antarctica it occurs in the atmosphere at other latitudes to a smaller extent. During the 1980s and 1990s, the average ozone concentration over Australia was about 6% less than the concentration prior to 1980.

This reduction in ozone has enabled more UV to reach the Earth’s surface; if the increase in UV had continued over the long term it was predicted to cause a reduction in plant growth, including important food crops, as well as a reduction in phytoplankton in the ocean, which is a major food source for marine life. These changes were in addition to the likelihood of significant increase in skin cancer and eye cataracts in humans and other animals. These risks caused the world’s governments to agree to a global phase down in the use of CFCs, known as the Montreal Protocol.

Montreal Protocol

In 1987, just two years after the link between CFC emissions and the damage to the ozone layer was demonstrated, the Montreal Protocol on Substances that Deplete the Ozone Layer was agreed upon by the 196 parties of the United Nation’s Vienna Convention for the Protection of the Ozone Layer. The Protocol required a 50% reduction in the use of ozone-depleting substances over ten years, including CFCs. This progressive phase-out placed binding obligations on both developed and developing countries to remove these gases from use and replace them with less damaging alternatives. The Montreal Protocol came into force at the start of 1989. It is the only treaty to be ratified by all members of the United Nations and is considered to be the most successful international environmental treaty to date.

Australia was one of the countries that helped negotiate the Montreal Protocol and was one of the first to sign in 1988, ratifying the Protocol by passing it through Parliament less than a year later. Upon ratification, the then Minister for the Environment and the Arts, Senator Graham Richardson announced that:

This is the first time there has been a commitment by countries around the world to control emissions of harmful chemicals before serious environmental damage becomes apparent.

Australia has supported this international initiative and has taken an active part in the negotiations leading up to this historic agreement.

The Ozone Protection Bill 1989 was passed through Federal Parliament, which introduced legislation that controlled not only the use of CFCs and related gases, but their production, import and export. Minister Richardson announced that this legislation was:

One of the world's most stringent pieces of legislation controlling and reducing the manufacture and use of CFCs and halons… Under this legislation, by 1995 Australia will have reduced its consumption of ozone depleting substances by 50%. We will achieve the target of the Montreal Protocol in half the time required by the Protocol.

Effect of the Montreal Protocol

The Montreal Protocol has been very successful at achieving its goals, both in Australia and internationally. A 2016 review of Australia’s Ozone Protection and Synthetic Greenhouse Gas Programme found that the country had phased out 99% of the ozone-depleting substances covered by the Montreal Protocol.

The September hole in the ozone layer over Antarctica reached its thinnest in 1994 and has since been slowly improving. A 2018 study by NASA shows that the hole has ‘thickened’ by about 20% since 2005 and that this increase directly correlates to the reduction in CFCs in the Antarctic atmosphere.

Next steps

Since the Montreal Protocol started, a number of amendments have brought forward scheduled phase-outs, as well as added new chemicals to be controlled. The latest is the 2016 Kigali Amendment, which adds hydrofluorocarbons (HFCs) to the Montreal Protocol. HFCs were developed as a replacement to CFCs and HCFCs for use in refrigeration and air-conditioning equipment, as they were considered less damaging to the ozone layer. However, research has since determined that some HCFCs and HFCs have a global warming effect that can be hundreds or thousands of times stronger than carbon dioxide. Under the Kigali Amendment, parties to the Montreal Protocol must phase down their production and import of HFCs by 85% between 2019 and 2036.

Australia was one of the co-chairs of the negotiation of the Kigali Amendment, and one of the first ten countries to sign. An amendment to the Ozone Protection and Synthetic Greenhouse Gas Management Act 1989 passed Parliament, enforcing the HFC phase-down in Australia from 1 January 2018.

By restricting the use of HFCs, the Kigali Amendment is also predicted to ‘prevent up to 0.5 degrees Celsius of global warming by the end of this century, while continuing to protect the ozone layer’. This ‘could be the single largest real contribution the world has made so far towards keeping the global temperature rise "well below" 2 degrees Celsius’.

The Montreal Protocol remains the premier example of international cooperation through the United Nations to negotiate effective action on global environmental issues, as well as showing the significant role Australia can play in multilateral negotiations.