A curious piece in The Conversation describes a study on the link between the hole in the ozone layer and global warming. And you might think well, if the hole in the ozone caused a lot of warming then it leaves less warming for everything else to have caused including CO2. But it’s not that simple. The author says she and her colleagues ran some computer models with and without CFCs and related chemicals and it turns out if you set the parameters a certain way the CFCs, not the UV light getting in, caused a lot of warming. But hang on: If CFCs caused a good deal of warming and now they’re being phased out, doesn’t it still mean CO2 matters less after all, and warming should slow down? No of course not. It never means that.
The study contains the usual rhubarb about how “Record-breaking Arctic warming and the dramatic decline of sea ice are having severe consequences on sensitive ecosystems in the region” thus proving the validity of predictions made 40 years ago that the ice would vanish and so forth. (Speaking of predictions whose failure ought to have consequences, it’s remarkable the way organizations like, say, the Canadian government that knows better have decided to deal with the failure of that vanishing-Arctic-ice prediction by asserting over and over again that it came true.) But it’s the logic pretzel at the end that really requires attention.
Attributing blame for warming is like sharing out a pie. The bigger a slice Fred Chlorofluorocarbon gets, the smaller a piece Joe Carbon, Mr. Sun and the others can have. And vice versa. Which is why alarmists are so allergic to the (frankly obvious) natural warming cycle at the end of the Little Ice Age; it hogs the blame they are determined to pin on Joe Carbon. But it’s also why if arch-climate-villain Siegfried Methane is less dangerous than the IPCC has long maintained, as some now suggest (and not just cattle farmers who have some hide in the game) some of the concern can shift from it back to boring old CO2.
Or at least it would be so in any other field of science. But not once you go through the climate change looking glass. The Conversation article ends: “Thirty years ago, those who signed the Montréal Protocol were not thinking about climate change. Yet, research such as ours underscores the important role this agreement will play in mitigating future warming as the concentrations of ozone-depleting substances decline over time. That said, without massive reductions in carbon dioxide emissions in the coming decades, the gains we will achieve through the Montréal Protocol will be quickly overwhelmed. Further action is needed to protect the Arctic — and our planet.”
See? Even though CO2 is a far less potent GHG than we feared and the warming is slower, CO2 is just as potent as we feared and the warming just as fast. Quod Erat Adsumendum.