Two days ago, my sister Evangeline complained that it was too hot. “I thought we are not entering the Christmas season,” she pointed out. “But why is too hot? It’s even hotter compared to summer months.”
I’m sure no one will disagree with her. Our electric bills are going up because we are using our air-conditioners and electric/ceiling fans more often. We are opening our refrigerators every now and then to drink water or any liquid just to quench our thirst as temperature surges.
Is the weather going crazy? Is climate change really upon us now?
But there’s one thing we forget. What about our ozone layer? That’s the shield we have against the scorching heat of the sun. It must be remembered that in the past, ozone depletion was a big thing. Whatever happened?
I think it’s a good time to discuss about ozone layer again as this month, the international community observes the International Day for the Preservation of the Ozone Layer – or simply Ozone Day.
On September 16, 1987, some members of the United Nations signed the Montreal Protocol on Substances that Deplete the Ozone Layer. It wasn’t until a year later that the Philippines signed it and ratified it on March 21, 1991.
The Montreal Protocol is an international agreement that regulates the production and consumption of ozone depleting substances (ODS). Examples of ODS, which are tongue-twisters, are chlorofluorocarbons (CFCs), halons, carbon tetrachlorides (CTCs), methyl chloroforms (MCs), methyl bromides (MBs), hydrofluorocarbons (HFCS), and – the longest of them all! – hydrochlorofluorocarbons (HCFCs).
On January 1, 2010, the following substances had been phased out in the country, according to the Department of Environment and Natural Resources (DENR): CFCs, halons, CTCs, MCs, and non-quarantine and pre-shipment MBs.
Our country is also set to phase-out HFCs in 2024 while HCFCs are expected to be phase-out by 2040. HFCs are non-ODS alternatives to HCFCs but which have high global warming potential.
Are you asking why we need to protect our ozone layer?
The atmosphere our planet where we live is divided into several layers. According to science, the lower region – called troposphere – extends from the planet’s surface up to about 10 kilometers in altitude. (For the uninformed, Mount Everest, the tallest mountain on the planet, is only about 9 kilometers high.) All human activities occur in this layer.
Ozone at the ground level, at the bottom of the troposphere is a harmful pollutant. One of the greenhouse gases, it is actually a result from the exhausts of automobiles and other vehicles and other sources.
After the troposphere comes the stratosphere, which continues from 10 kilometers to about 50 kilometers. Most commercial airline traffic occurs in the lower part of the stratosphere. It is in this layer where the ozone shield is found.
“If all the ozone contained in the atmosphere from ground level to a height of some 50 kilometers could be assembled at the earth’s surface, it would comprise a layer of gas only about three millimeters thick, weighing some 3,000 million tons,” a science scribe wrote.
The ozone layer’s is our protective shield from the ultraviolet (UV) rays of the sun. Once it is thinner, then we will have excessive exposure to UV rays which make us susceptible to the skin cancers, damaged immune systems, and stunted growth.
If you don’t believe me, here’s what Meg Seki, executive secretary of the ozone secretariat of the United Nations Environment Program (UNEP): “The Montreal Protocol protects the stratospheric ozone layer which, in turn, protects human health and the environment by blocking most of sun’s harmful ultraviolet radiation from reaching the earth’s surface. Skin cancer can result from overexposure to the sun, so it is imperative for everyone to remain vigilant and ensure they protect themselves adequately with hats and sunscreen.”
Not that you don’t walk under the sun or stop going to the beach to swim. We need some sun, mainly for the production of vitamin D which helps to prevent the development of bone diseases such as rickets, osteomalacia, and osteoporosis. But too much sun can be dangerous – and even deadly.
Let me quote the words of renowned ozone hole expert Professor Susan Solomon of the Massachusetts Institute of Technology: “The ozone hole above the Antarctic is now smaller than it was around the year 2000, by about four million square kilometers.”
That’s a relief, indeed. But we should not be complacent though. The ozone hole still averages about 17 million square kilometers in size. “It isn’t completely healed,” Prof. Solomon pointed out, “but it’s better than the 21 million we had around 2000.”
