What Ever Happened To The Hole In The Ozone Layer?

If you are a Millennial, you have probably spent your whole life hearing about the “h

ole” in the ozone layer. Before you can understand the hole through, you gonne know what the ozone layer is.

The ozone layer isn’t really its own thing instead 90% ozone floots around the stratosphere about 10 to 50 KM above our heads. Ozone is 3 oxygen atoms linked together, O3. When in the stratosphere, ozone absorbs harmful UV-B radition, protecting us and other life here in the ground (in the troposphere).

In the late 19th and early 20th centuries, people were just beginning to harnless the power of refrigeration using toxic gases like ammonia, methyl chloride and sulfur dioxide. In 1928, an enterprising inventor at General Motors created a non-toxic chemical for refrigeration called CFC (chlorofluorocarbon). It was patented as Freon by DuPont and sold in air conditioners, fridges, bug sprays, spray paints, hair conditioners and helthcard products. And it’s peak companies were making a million metric tons of CFCs every year. Then in 1974 study in Nature found this great nontoxic refrigerant was wreakng on the atmospheric ozone layer. Sure at the sea level, CFCs are non toxic and safe for humans, but if they get into the upper atmosphere, they are subject to photodissociation where UV (ultra voilet) ratition breaks a Chlorine atom of the CFC (chlorofluorocarbon). If that the free chlorine finds a molecule of ozone (O3) it will react with it, destroying the ozone by ripping off one of it’s oxygen atoms to make Chlorine Monoxide, leaving regular old O2 or oxygen. Then the Chlorine Monooxide gets hit by UV and broke up again. so it has to find another O3 molecule to stabilize it and the cycle repeats itself. It’s bad.

In 1977, the ozone layer was fine. By 1981, there were hints something was amiss. Then in 1984, scientists suddenly registered a giant hole in the ozone layer. They published their findings and in 1987, the Montereal Portocal was signed, beginning the phasing out CFCs shortly thereafter. Meanwhile even throught the house was clearly on fire, Du Pont and other companies insisted everything was fine and fought thooth and nail to keep CFCs legal. But they finally relented after scientific evidence became indisputable. A looming environmental disaster that pitted corporations againsts the scientific community. Those CFCs can hide in the atmosphere for 40 to 150 years, withouh the emission of new CFCs, eventually that free chlorine cycle will stop. If the chlorine runs into some methane (CH4) up there, it would break it up forming hydrogen chloride (HCL) which is stable enough to rain down to Earth.

In 2015, about 30 years after the Protocol was signed, the ozone hole reached the largest size EVER. But since the peak (due mostly to volcanic erutions that sprew bromine, another Ozone depleting gas), scientists have finally started to see the ozone layer repair itself ! A study published in Science last year found the hole had decreased in size from the year 2000 and the most of that decrease was specifically because of the MOntereal Protocol..
Without the chlorine wafting up into the stratosphere, ozone was able to form naturally, when UV light breaks up regular old oxygen from O2 into O3. Without the chlorin to messit up, this process could restart! It can still be messed up by volcanic eruptions but overall withoud our meddling, the ozone layer may someday be back to normal. Based on the new study, the ozone layer might be back to 1980 levels by 2040. You can actually see how the ozone layer is doing right now on the NASA’s website.

This is science, so we can’t have all happy endings. We still need AC and fridges and the replacement gas, HFCs(hydrofluorocarbons) are a potent greenhouse gas. So now, global warming is a concern. We can never win !

Ozone Layer