Remember the hole in the ozone? Which we’ve managed to decrease substantially thanks to a rare willingness for the world to get together and do the right thing? Turns out that, but for a happy accident, the ozone hole might have killed us all.
Looking back, it’s remarkable to ponder the serendipity of these discoveries—and how little margin for error we had. As luck would have it, DuPont had been using chlorine instead of bromine to produce CFCs. As far as anyone could tell, the two elements were interchangeable. But, as another prescient ozone researcher, Paul Crutzen, later noted, bromine is 45 times as effective at destroying ozone as chlorine. Had DuPont chosen to use bromine, the ozone hole could well have spanned the globe by the 1970s instead of being largely confined to Antarctica—long before anyone had a glimmering of the problem. It’s not hard to see what massive worldwide ozone depletion would’ve meant. Punta Arenas, the southernmost town of Chile, sits under the Antarctic ozone hole, and skin cancer rates there have soared by 66 percent since 1994. If humans had destroyed stratospheric ozone across the globe, we would likely be unable to set foot outdoors without layers of sunscreen and dark shades to prevent eye damage. Worse, the excess UV rays could have killed off many of the single-celled organisms that form the basis for the ocean’s food chain and disrupted global agriculture (studies show that bean and pea crop yields decline about 1 percent for every percent increase in UV exposure).
Happily, though, scientists did discover the ozone hole. And, despite industry warnings that abolishing CFCs would impose unbearable costs, world leaders agreed to phase out the chemicals in 1987, and economic ruin never arrived. DuPont developed a substitute for CFCs, and ozone levels in the atmosphere have stabilized, with the hole over Antarctica expected to heal by 2050. A topic that once graced the cover of Time and generated heated congressional debates now barely gets mentioned. We learned to stay within one planetary boundary without impeding human prosperity. That should give us every reason to think we can respect the others we are now barreling past.
What’s frightening is that this lucky accident of using chlorine over bromine was simply that chlorine was cheaper. Somewhere in the multiverse, there’s an alternate world doing far, far, worse because there was a run on chlorine that caused Dow to go with bromine instead.
Our world barely missed the apocalypse by accident. But with so many other threats out there being ignored, how long can our luck hold out?