Muscat - There has been a substantial reduction in ODSs emissions over the last two decades, and there is evidence that the ozone layer is healing itself and can recover by the middle of this century, according to the UN Environment Programme (UNEP), thanks to the agreement.
The Antarctic Zone hole is expected to close by the 2060s, while other regions will return to pre-1980s values even earlier. To date, nearly 99 percent of ODSs have been phased out, UNEDP said.
The Sultanate of Oman has acceded to the Vienna Convention for the Protection of the Ozone Layer and the Montreal Protocol by Decree (73/98) and is now implementing the third phase of the Hydrochlorofluorocarbons (HCFC) phase-out strategy project in cooperation with the United Nations Environment Program and the United Nations Development Organization, the Civil Aviation Authority said in a statement.
“We celebrate 35 years of the Montreal Protocol’s success in protecting the stratospheric ozone layer against synthetic chemicals that also cause climate heating,” said Secretary-General Antonio Guterres in his message to mark the international day.
The Montreal Protocol, which was adopted in 1987 and entered into force in 1989, is considered one of the world’s most successful environmental treaties. “Thanks to a global agreement, humanity has averted a major health catastrophe due to ultraviolet radiation pouring through a massive hole in the ozone layer,” the Secretary-General said.
The Protocol provides a set of practical ways to phase out ODSs – including through stringent measures worldwide to control products containing the chemicals.
In 2016, the Protocol was amended in Kigali to also phase out the production and use of hydrofluorocarbons (HFCs) - which became a replacement for ODSs but proved to be more potent than carbon dioxide, and detrimental to the climate.
35 years ago, the Montreal Protocol to Protect the Earth's Ozone Layer was born, to which 197 countries and the European Union committed themselves, marking a global effort to tackle climate change and reduce emissions that deplete the ozone layer.
What is the ozone layer?
The ozone layer is a thin shield of gas in the Earth’s atmosphere that protects the planet, absorbing the sun’s ultraviolet (UV) rays and helping to preserve all life on the planet. But the ozone layer is not immune to harmful human activities. A collection of human-made greenhouse gases known as ozone-depleting substances (ODSs), including chlorofluorocarbons that can be found in everyday products such as air conditioners, refrigerators, and aerosol cans, have been destroying the ozone layer.
Why does it matter?
The consequences of any damage to the ozone layer are multifold. Harmful ODSs can carve a hole in the ozone layer, allowing UV rays to directly hit the Earth. Long-term exposure to UV radiation threatens human life - causing skin cancer, eye diseases, and other health problems - and seriously harms most animals, plants, and microbes. Moreover, many ozone-depleting substances are also potent greenhouse gases that contribute to climate change when they accumulate in the atmosphere and warm the planet.
Scientists have also noted that ozone protection efforts have evidently slowed climate change by avoiding an estimated 135 billion tons of carbon dioxide equivalent emissions from 1990 to 2010. A successful reduction in HFCs in the atmosphere can avoid up to 0.4 degrees Celsius of global temperature rise by 2100 while continuing to protect the ozone layer.
For humans, the Montreal Protocol has potentially helped to prevent up to 2 million cases of skin cancer globally each year by 2030 and resulted in an estimated US$1.8 trillion in health benefits, mostly in skin cancer treatment alone.
“The Montreal Protocol stands ready to provide more: to protect all life on Earth, create a cooler environment, and safeguard biodiversity to help feed growing populations,” said Inger Andersen, the head of UNEP, in her message for the day.
What causes the thinning of the ozone layer around the globe and the “ozone hole” above Antarctica?
Manmade chemicals containing halogens were determined to be the main cause of ozone loss. These chemicals are collectively known as ozone-depleting substances (ODSs). ODSs were used in literally thousands of products in people’s daily lives around the world.
The most important ODSs were chlorofluorocarbons (CFCs), which at one time were widely used in air conditioners, refrigerators, aerosol cans, and in inhalers used by asthma patients. Other chemicals, such as hydrochlorofluorocarbons (HCFCs), halons, and methyl bromide also deplete the ozone layer. Most of our computers, electronics, and parts of our appliances were cleaned with ozone-depleting solvents. Car dashboards, insulation foams in our houses and office buildings, water boilers, and even shoe soles were made using CFCs or HCFCs. Offices, computer facilities, military bases, airplanes, and ships extensively used halons for fire protection. A lot of the fruit and vegetables we ate were fumigated by methyl bromide to kill pests.
How do these chemicals deplete ozone?
When a CFC molecule reaches the stratosphere, it eventually absorbs UV radiation, causing it to decompose and release its chlorine atoms. One chlorine atom can destroy up to 100,000 ozone molecules. Too many of these chlorine and bromine reactions disrupt the delicate chemical balance that maintains the ozone layer, causing ozone to be destroyed faster than it is created.