by Amro Al-Zoubi/Jordan
John Carl Alonsagay/Philippines
Dr. Alemayehu Kefalew/Ethiopia
Graphic by Javan Lev Poblador/ATO - ClimatEducate Project
Ozone is the gaseous layer that exists 10 to 60 kilometers above the earth’s surface, in the stratosphere. It protects lives on earth by filtering out most of the sun’s harmful ultraviolet UV radiation. Ozone depletion is referred to as thinning of the ozone layer and was first discovered by scientists in the 1970s.
The depletion of the Ozone layer would allow more UV radiation to reach the Earth’s surface and consequently risks human health. Some negative effects of ozone depletion include skin cancers and immune deficiency disorders. The depletion would also affect terrestrial ecosystems, altering growth, food chains, and biochemical cycles. Aquatic life under the water’s surface, which is the basis of the food chain, could also be affected by high UV levels. UV radiation does not only harm human and animal lives, but also negatively impacts plants, affecting its growth and reducing agricultural productivity.
Ozone depletion is greatest at the South Pole, which occurs in early spring (August-November) and peaks in October. This severe depletion is often called an ‘ozone hole’ and it was seen by the scientists using satellite observations. Although less radical, ozone depletion is also observed over the Arctic and continental Europe.
The chart below shows the development of the maximum annual size of the ozone hole over the Antarctic. It can be seen from the chart that the hole started to decrease after the year 2000. This is presumably due to an international agreement titled as "Montreal Protocol" that urged the world to protect the earth’s ozone layer from substances emitted by human activities.
The Montreal Protocol has defined over 90 chemicals as ozone-depleting substances; and arguing countries around the world has shown their efforts to decrease the use of these substances. Global consumption of ozone-depleting substances has been reduced by 98% since countries began taking action under the Montreal Protocol.
Figure 1: Maximum Ozone Hole Area. Source: European Environment Agency (February 2020)
Although the Montreal Protocol has played a huge role in decreasing the depletion of the ozone layer and allowing it to start recovering, much is still needed to be done to ensure a steady recovery.
Atmospheric concentrations of ozone depend naturally on many factors such as the temperature, weather, latitude, and altitude; and substances emitted by natural events such as volcanic eruptions can also affect ozone levels.
In fact, the ozone layer is not only being depleted by a natural event but also by anthropogenic effects that include the use of a wide range of industrial and consumer applications such as refrigerators, air conditioners, and fire extinguishers. Most of these ozone-depleting substances remain in the stratosphere for decades, causing a very slow recovery for the ozone layer.
In order to decrease the depletion of the ozone layer, industries must decrease and eventually stop relying on the use of ozone-depleting substances. In 1987, the first international treaty was signed by all countries of the world and is considered the greatest environmental success story in the history of the United Nations. Leading to the establishment of the Montreal Protocol on ozone-depleting substances, which aims to cut down the production and consumption of ozone-depleting substances.
Almost all man-made ozone-depleting substances are also greenhouse gases, which contribute to Climate Change. Therefore, by phasing-out ozone-depleting substances such as Hydrochlorofluorocarbons (HCFCs) and Chlorofluorocarbons (CFCs), would also make a significant positive contribution to the fight against climate change, considering their significant global warming effect.
In order to decrease the depletion of the ozone layer, governments of the world must establish strict and advanced legislation on ozone-depleting substances.
It’s worth mentioning that the global phase-out of ozone-depleting substances defined by the Montreal Protocol has led to a large increase in the use of other types of gases, such as the fluorinated gases, which do not damage the ozone layer but have a significant global warming effect. Therefore, in 2016, Parties to the Montreal Protocol agreed to add the most common type of fluorinated gases, hydrofluorocarbons (HFCs), to the list of controlled substances.
Amro El-Zoubi is currently a project member of the ATO - ClimatEducate Project. He has a master’s degree in Environmental Engineering and Land Planning from Politecnico di Milano, Italy. He is a resourceful and courageous engineer, experienced in climate change mitigation, chemicals, and waste management, and passionate about sustainable development and the resilient built environment.
John Carl Alonsagay is currently the project liaison officer and the organization president of the ATO. He has an undergraduate degree in education. He studied environment and natural resource management at the East-West Center in Honolulu, Hawai’i. He currently does his graduate studies at the University of the Philippines Open University (UPOU). He is an enthusiast in climate policy, bioculturalism research, language, conservation, and graphic designing.
Dr. Alemayehu Kefalew is currently a project member of the ATO - ClimatEducate Project in Africa and a facilitator for ClimatEducate Educators' Network. He has an undergraduate degree in Teaching Biology from Debub University (Ethiopia). He did his M.Sc in Botanical Science and PhD in Vegetation Ecology from Addis Ababa University (AAU, Ethiopia). He has published books and research articles on reputable journals. He is now working as a lecturer in Botany in Debre Markos University, Ethiopia. He has a strong interest in environmental education and climate action.