
A couple of nights ago, the Democratic pretenders to the presidential throne once more assembled inside my boob tube to debate. Some wanted Medicare for All. Others, Medicare for All Who Want It. Still others, Medicare for Apathetic People on Alternate Days of the Week. Tom Steyer was one of the ten contenders, seated on the far-right edge of the stage near the exit sign. A billionaire and environmental activist, Steyer stated that the U.S. Congress has never passed significant climate change legislation. My older brother, parked in my favorite purple wingback chair and glancing between the TV, his cellphone and his laptop; my brother, a multi-thousandaire and author of Hawai’i: Eight Hundred Years of Political and Economic Change; my brother, rarely shy to interject his opinion, muttered, “That’s not true.” Brilliantly, I responded: “Yes, it is.” His riposte: “No, it’s not. Ozone legislation.” I returned: “That was environmental legislation, not climate. Climate has a different chemistry.” He grumbled dismissively.
Oh no, here we go into the ozone – battling brothers edition. The upshot is that he was wrong, and right, and I was right, and wrong. Turns out, ozone is complicated.
As a popular meme, ozone first appeared in the early 1990s when President George H.W. Bush (RIP) labeled vice-presidential candidate Al Gore “ozone man” for his preoccupation with climate change. Tarring Big Al as kooky green was a family project, with George W. Bush snidely employing “ozone man” in the 2000 presidential election. Maybe it won him Florida.
Oh no, here we go into the ozone – battling brothers edition. The upshot is that he was wrong, and right, and I was right, and wrong. Turns out, ozone is complicated.
As a popular meme, ozone first appeared in the early 1990s when President George H.W. Bush (RIP) labeled vice-presidential candidate Al Gore “ozone man” for his preoccupation with climate change. Tarring Big Al as kooky green was a family project, with George W. Bush snidely employing “ozone man” in the 2000 presidential election. Maybe it won him Florida.

Ozone is three oxygen atoms bonded together. It exists naturally in the Earth's atmosphere, as a layer in the stratosphere that protects us from full bombardment of ultraviolet radiation. Chemicals called CFCs (chlorofluorocarbons), used commonly as aerosols and refrigerants, degraded strastospheric ozone in the second half of the 20th century, causing a hole in the ozone layer over Antarctica. This allowed more UV rays to penetrate, which is very bad because UV radiation plays a major role in causing non-melanoma skin cancers (basal cell carcinoma, squamous cell carcinoma) and malignant melanomas. Rich people couldn't think of a good way to buy themselves out of this fairly immediate threat to their health and still enjoy the sunshine, so they allowed the international community to produce the Montreal Protocol in 1987, which phased out CFCs and most other substances destroying the ozone layer. And it worked; the ozone layer stopped declining around 1995.

The Montreal Protocol, technically, was not legislation produced by Congress. It was an international treaty that the U.S. signed and then Congress ratified. Moreover, the treaty wasn't designed to fight climate change; the focus was almost entirely on preventing cancer. However, CFCs also happen to be potent greenhouse gases. They are far less abundant than CO2 but more powerful and longer lasting in the atmosphere. So, by happy accident, or lucky happenstance, the banning of CFCs did reduce the emission of a category of greenhouse gases that contributes to climate change. But it did not address the main driver of climate change: the burning of fossil fuels. And it wasn't hard to do, giving up cans of explosive hair spray and putting new chemicals in refrigerators. Limiting climate change by radically changing the global energy, transportation and agricultural sectors -- that's gonna by a doozy.

So, this Thanksgiving, if your contentious brother or wacky, denialist uncle or persnickety gramma starts up about ozone, you're ready. Check out the Skeptical Science website for quick comebacks about 197 global warming myths! The idea that the ozone layer is somehow causing global warming is covered in myth #137. Finally -- relax, class, we're almost done -- there's also a form of pollution called ground-level ozone. It has nothing to do with the ozone layer, but is a major component of summertime smog caused by the interaction of heat, sunlight and industrial byproducts associated with fossil-fuel combustion. Okay, that's it, there's the bell, bye-bye everybody.