MSNBC writes up two new studies on the links between global warming and the ozone layer and the results are... a bit maddening, to be honest. To recap, the Montreal Protocol of the late 1980s was incredibly successful at saving the ozone layer—the nations of the world banded together, brushed off the industry-funded deniers who were screaming that the science was "uncertain," agreed to phase out CFCs, and, as a result, the ozone layer has slowly been recovering. Recently, though, scientists writing in Geophysical Research Letters say they've discovered that as the hole in the ozone over Antarctica shrinks, the continent could start warming even further as a result. That's... not encouraging, even though banning CFCs was still necessary and proper.
The other study comes from Science, and reports that one of the more "promising" geoengineering ideas out there—a proposal to inject sulfates into the air to mimic the cooling effect that was caused by the eruption of Mount Pinatubo in 1991—could end up obliterating the ozone layer in the Arctic (which would, in turn, affect large swaths of the Northern Hemisphere; since the ozone shields us from cosmic radiation and whatnot, this would be a rather suboptimal outcome). This comes on the heels of an earlier study suggesting that the sulfate plan would wreak havoc on global rainfall patterns.
Anyway, trying to avert catastrophic climate change by decarbonizing the global economy is, as Brian says, an incredibly daunting task, but it still looks far less daunting to me than trying to muck with an extremely complex climate system via these wacky geoengineering schemes.
--Bradford Plumer