Tim Flannery on CFCs

Had humans found bromine cheaper or more convenient to use than chlorine, it is quite likely that by the time Crutzen and his colleagues made their discovery, we would all have been enduring unprecedented rates of cancer, blindness and a thousand other ailments, that our food supply would have collapsed, and that our civilisation itself was under intolerable stress. And we would have had no idea of the cause until it was too late. (CiB link)