by Laura Spacey –
33 years after the Montreal Protocol was finalised, there is now clear evidence to show that it is having a significant impact on the ozone layer. A recent report, published in Nature, has shown that the tables have turned and that ozone levels over Antarctica have risen by 8% per year (2001-2013) in some areas1. This not only means that ozone layer should be healed completely by the end of this century, but that decisive, global action can have strong impacts on our planet.
What is Ozone?
Ozone (O3) is a greenhouse gas that protects the Earth from harmful UV rays, which can cause skin cancer and damage crops. The ozone layer is protected under the Montreal Protocol3.
What is the Montreal Protocol?
The Montreal Protocol was a landmark piece of international agreement that came about because of the 1985 report by the British Antarctic Survey that showed O3 depletion had occurred faster than anyone had previously thought2. A later report showed that CFCs (chlorofluorocarbons) were to blame3. They convert ozone through a series of chemical reactions into oxygen (O2). The response from the international community was quick, that same year the Vienna Convention was introduced, which led the way for the Montreal Protocol in 1987. The protocol meant that all major Ozone Depleting Substances (ODSs) had to be phased out by 20103. Knowing the current levels of the ozone is critical in making sure the agreement is being followed. So, how is it done?
An ozonesonde being launched at Mauna Loa Observatory in Hawai’i. Image: NOAA Earth System Research Laboratories esrl.noaa.gov
How was the research carried out and what were the results?
Finding out about ozone levels is no easy feat. Data was collected inside the south polar vortex region, from nine Antarctic research stations. This study is the first to measure solely inside the polar vortex region! This was done because ozone loss occurs primarily within the polar vortex zone in the spring, when the loss is greatest1. To collect this data, an ozonesonde (pictured below), which is a modified weather balloon that collects ozone levels, temperature and pressure, up to 35km4, is used. Incredibly, this report shows that at 15km the ozone levels had increased by 8% per year, a significant and substantial change. There was increases all throughout the ozone layer, with a 2% increase per year at 12km and at 22km1. This puts the ozone layer on track to fully heal by 2060, in line with a recent report by the United Nations5.
Conclusion
This report is important not only because it shows that the ozone layer is healing, which is good news for the Antarctic ice sheet, but it shows that global collaboration works. The success of this protocol gives hope to the international community that similar agreements made about climate change may be successful. This is a climate issue that was discovered and dealt with in the space of one lifetime, so why couldn’t climate change be the same?
References
- Kuttippurath, J. and Nair, P. (2017) The signs of Antarctic ozone hole recovery. Scientific Reports, 7, 585.
- Farman, J. C., Gardiner, B. J., Shanklin, J. D. (1985) Large losses of total ozone in Antarctica reveal seasonal ClOx/NOx interaction. Nature, 315, 207-10.
- Middleton, N. (2019) Global Casino. New York: Routledge.
- National Ocean and Atmospheric Association (2008) https://www.ozonelayer.noaa.gov/action/ozonesonde.htm (2/12/2020).
- World Meteorological Organisation. (2018) Scientific Assessment of Ozone Delepletion: 2018. Global Ozone and Monitoring Project,
