Sept 16: International Day for the Preservation of the Ozone Layer

The ozone layer, at about 20 km above the earth’s surface, offers a protection against harmful ultra-violent radiation. (HANDOUT PHOTO)

Sept. 16 recognizes the date in 1987 when the Montreal Protocol on substances that deplete the ozone layer was signed.

But 26 years later the ozone layer, which wraps around the planet like a blanket about 20 kilometres above the surface and filters out damaging ultraviolet rays from the sun, is still struggling to recover.

And the Arctic remains at risk of those increased levels of harmful radiation that can cause long-term skin damage and cancer. That became clear in 2011, when a huge hole in the ozone layer opened up over Arctic Canada in the late winter and spring, exposing people, animals and marine life to more UV radiation.

On Sept. 16, the International Day for the Preservation of the Ozone Layer, the United Nations’ International Day for the preservation of the ozone layer, the focus is on the importance of protecting human health and the environment.

“Extraordinary challenges require extraordinary responses,” said Ban Ki Moon, the UN Secretary-General. “A generation ago, the world’s nations agreed to act definitively to protect the ozone layer, initiating an inter-governmental process that blazed new trails.”

But now he’s urging “governments, industry, civil society and all other partners to apply the same spirit to the other great environment and development challenges of our times.”

In the 1987 Montreal Protocol, nations said they would phase out and ban chemicals such as chlorofluorocarbons, or CFCs, found in aresol products, which contribute to ozone destruction.

But, many of these chemicals, along with new ozone-harming substances, are still in use.

And scientists now point to the growing connection between ozone loss and global warming.

That’s because heat-trapping greenhouse gases keep warmth next to the earth’s surface. These prevent the heat from rising and warming up the upper atmosphere and create the extremely cold conditions in the upper atmosphere which are ideal for CFCs to turn into ozone-destroying substances.

That happened in 2011 when a hole in that ozone layer, covering two million sq. km., allowed high levels of harmful ultraviolet radiation to hit large swaths of northern Canada, Europe and Russia.

The worst enemies of the ozone layer, produced thousands of kilometres to the south of the Arctic, include:

• CFCs — CFCs are used in aerosol products, as sterilants of medical equipment, and in food freezing, tobacco expansion, fumigation and cancer therapy;

• Halon — Halon 1211 has been widely used in portable fire extinguishers, Halon 1301 has seen widespread use in fixed systems throughout the industrial, commercial, marine, defence, and aviation industries, and Halon 2402 has primarily been used in the defence, industrial, marine and aviation sector in some countries;

• HCFCs — Hydrochlorofluorocarbons are widely used in the refrigeration, foam, solvent, aerosol and fire fighting sectors as a transitional substance to substitute CFCs. HCFCs are also used in the production of other chemical products;

• Methyl bromide — Methyl bromide is widely used as a fumigant in agriculture, for pest control in structures and stored commodities, and for quarantine treatments; and,

• Solvents, coatings and adhesives.