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Context:
World Ozone Day 2024 was celebrated on 16th September globally.
What is ozone?
- Ozone is a gas that occurs both in the Earth’s upper atmosphere and at ground level.
- It is a special form of oxygen molecule that contains three oxygen atoms with formula O3.
- Most atmospheric ozone is concentrated (about 90%) in a layer in the stratosphere, about 9 to 18 miles (15 to 30 km) above the Earth's surface.
- At any given time, ozone molecules are constantly formed and destroyed in the
Importance of the ozone layer
- The ozone layer in the stratosphere absorbs a portion of the radiation from the sun, preventing it from reaching the planet's surface.
- Most importantly, it absorbs the portion of UV light called UVB.
- UVB has been linked to many harmful effects, including skin cancers, cataracts, and harm to some crops and marine life.
- Because of this beneficial role, stratospheric ozone is considered “good” ozone.
Bad ozone
Excess ozone at Earth’s surface that is formed from pollutants is considered “bad” ozone because it can be harmful to humans, plants, and animals.
Ground-level or “bad” ozone is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight.
Emissions from industrial facilities and electric utilities, motor vehicle exhaust, gasoline vapors, and chemical solvents are some of the major sources of NOx and VOC.
Breathing ozone can trigger a variety of health problems including chest pain, coughing, throat irritation, and congestion.
It also damages vegetation and ecosystems. It leads to reduced agricultural crop and commercial forest yields, reduced growth and survivability of tree seedlings, and increased susceptibility to diseases, pests and other stresses such as harsh weather.
Depletion of ozone layer and formation of ozone hole
- This “good” ozone is gradually being destroyed by man-made chemicals referred to as ozone-depleting substances (ODS), including chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, methyl bromide, carbon tetrachloride, and methyl chloroform.
- These substances were formerly used and sometimes still are used in coolants, foaming agents, fire extinguishers, solvents, pesticides, and aerosol propellants.
How it works
- Once released into the air these ozone-depleting substances degrade very slowly.
- In fact, they can remain intact for years as they move through the troposphere until they reach the stratosphere.
- There they are broken down by the intensity of the sun’s UV rays and release chlorine and bromine molecules, which destroy the “good” ozone.
- Scientists estimate that one chlorine atom can destroy 100,000 “good” ozone molecules.
How Does the Depletion of “Good” Ozone Affect Human Health and the Environment?
- Human Health: Ozone depletion can cause increased amounts of UV radiation to reach the Earth which can lead to more cases of skin cancer, cataracts, and impaired immune systems.
- Overexposure to UV is believed to be contributing to the increase in melanoma, the most fatal of all skin cancers.
- Crop damage: UV can also damage sensitive crops and reduce crop yields.
- Marine food chain: Some scientists suggest that marine phytoplankton, which are the base of the ocean food chain, are already under stress from UV radiation.
- This stress could have adverse consequences for human food supplies from the oceans.
Steps taken
Vienna Convention for the Protection of the Ozone Layer
- This was formalized in the Vienna Convention for the Protection of the Ozone Layer, which was adopted and signed by 28 countries, on 22 March 1985.
- In September 1987, this led to the drafting of The Montreal Protocol on Substances that Deplete the Ozone Layer.
The Montreal Protocol and Kigali Agreement
- The Montreal Protocol on Substances that Deplete the Ozone Layer is considered the world’s most successful international environmental treaty.
- It was adopted on 16 September 1987 and entered into force in 1989.
- Universal ratification: On 16th September 2009, the Vienna Convention and the Montreal Protocol became the first treaties in the history of the United Nations to achieve universal ratification.
- Under the Protocol, nations phased out chlorofluorocarbons (CFCs) – a class of compounds that were used mostly in aerosol sprays, refrigerants, foams and as solvents, and were damaging the protective ozone layer.
- Because ozone-depleting substances and many of their substitutes are also potent greenhouse gases, their phase-out under the Montreal Protocol is critical to international efforts to address climate change.
Kigali agreement
- A landmark agreement was reached October 15, 2016, at the 28thMeeting of the Parties of the Montreal Protocol in Kigali, Rwanda, to phase down hydrofluorocarbons (HFCs).
- On January 1, 2019, the Kigali Amendment entered into force.
- HFCs are not harmful to the ozone layer, but a fast-growing source of potent greenhouse gases contributing to climate change.
- HFCs are widely used in refrigeration and air conditioning, foam blowing, and other applications.
- The Kigali Amendment sets out a schedule of targets and timetables for all developed and developing countries to phase down their use of HFCs (Phase-out by 2030 in developed countries and 2040 in developing countries).
- The amendment links these control requirements with a renewed commitment by developed countries to provide financial support for developing countries through the Protocol’s Multilateral Fund.
The Multilateral Fund
- The Multilateral Fund for the Implementation of the Montreal Protocol was established in 1991 under Article 10 of the treaty.
- The Fund's objective is to provide financial and technical assistance to developing country parties to the Montreal Protocol whose annual per capita consumption and production of ODS is less than 0.3 kg to comply with the control measures of the Protocol.
- Since its inception, the Multilateral Fund has supported over 8,600 projects including industrial conversion, technical assistance, training and capacity building worth over US$3.9 billion.
Success achieved to date and the job ahead
Recovery of Ozone hole
- Globally, the ozone layer is expected to return to average 1980 levels by 2040. The Antarctic ozone hole will persist until 2066.
- It has been estimated that the Montreal Protocol is saving an estimated two million people each year by 2030 from skin cancer.
- To date, the Parties to the Protocol have phased out 98% of ODS globally compared to 1990 levels.
Reduction in global temperature
- From 1990 to 2010, the treaty’s control measures are estimated to have reduced greenhouse gas emissions by the equivalent of 135 gigatons of CO2, the equivalent of 11 gigatons a year.
- Under the Kigali Amendment, actions to limit the use of HFCs are expected to prevent the emissions of up to 105 billion tonnes of carbon dioxide equivalent of greenhouse gases, helping to avoid up to 5 degree Celsius of global temperature rise by 2100 and will keep the global temperature rise "well below" 2 degrees Celsius, a target agreed at the Paris climate conference.
Sustainable Development Goal
The Montreal Protocol also makes important contributions to the realization of the UN Sustainable Development Goals.
World Ozone Day 2024
- 16 September the International Day for the Preservation of the Ozone Layer, commemorating the date of the signing, in 1987, of the Montreal Protocol.
- The General Assembly of the United Nations vide resolution, 49/114, of December 1994, designated 16 September as the World Ozone Day.
- This year’s theme is: Montreal Protocol: Advancing Climate Action.
Must read articles
Ozone: https://www.iasgyan.in/daily-current-affairs/ozone#:~:text=Why%20is%20Ozone%20Layer%20important,most%20of%20the%20ocean%20life.
Ozone pollution: https://www.iasgyan.in/daily-current-affairs/ozone-pollution-in-delhi
Source:
https://www.epa.gov/sites/default/files/documents/gooduphigh.pdf
https://www.un.org/en/observances/ozone-day/science
https://www.unep.org/ozonaction/who-we-are/about-montreal-protocol
https://www.un.org/en/observances/ozone-day
https://www.dcceew.gov.au/about/news/world-ozone-day-2024
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PRACTICE QUESTION
Q.Discuss the causes, consequences, and global efforts to mitigate ozone depletion. How can international cooperation address this environmental challenge effectively? (250 Words)
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