(CU)_It has been a known fact that the ozone layer is the gas which protects the planet Earth from harmful levels of ultraviolet radiation (UV) of the sun. This is why the Montreal protocol became the only UN treaty ever to be ratified by every country on Earth, with the aim of regulating the production and consumption of nearly 100 man-made chemicals, namely chlorofluorocarbons (CFCs) which were once commonly used in refrigerators.
More than three decades later, a group of experts from the United States, the United Kingdom and New Zealand have found that the ban on these toxic chemicals gave humans a fighting chance of limiting global warming to 1.5°C as set out by the Paris accord. The authors of the report conducted their study based on a theoretical rise in CFC use of 3 per cent a year since 1987, and found that the ozone-wrecking chemicals, which were also used in insulation foams and aerosols, would have driven global warming by an extra 2.5°C. And since the current level of warming is about 1.2°C, we would have been facing 3.5°C of warming if CFCs were still in use.
According to the experts, without the ban on the harmful chemicals, CO2 in the atmosphere would have been 40 to per cent higher from the present-day levels of 420 parts per million, based on projected fossil fuel emissions. Accordingly, the additional carbon dioxide would have increased global warming by 0.8°C, leaving the goals of the Paris accord in tatters. On the other hand, CFCs are also powerful greenhouse gases. If they had not been regulated over 30 years ago, they would have boosted global warming by another 1.7°C, by the end of this century.
“A world where these chemicals increased and continued to strip away at our protective ozone layer would have been catastrophic for human health, but also for vegetation,” Dr Paul Young, the lead author of the report, said. “With our research, we can see that the Montreal protocol’s successes extend beyond protecting humanity from increased UV to protecting the ability of plants and trees to absorb CO2.”
“Although we can hope that we never would have reached the catastrophic world as we simulated, it does remind us of the importance of continuing to protect the ozone layer,” he added.
