Okay, let's stay calm. First the review: CFCs are chlorofluorocarbons, molecules that contain chlorine, fluorine, and carbon, and were used as refrigerants (and whatnot) for many years. Unfortunately, these long-lived molecules make their way into the stratosphere, where they interact (read destroy) ozone. This is an unambiguously bad thing because that ozone resides in the "ozone layer." The ozone layer is an unambiguously good thing because ozone strongly absorbs ultraviolet light, which damages and mutates living cells. So the OZONE LAYER stops the ULTRAVIOLET RADIATION from giving us SKIN CANCER, but the CFCs destroy the OZONE, allowing harmful radiation to reach the surface. Okay that is the CFC science review. As for the history, basically some chemists (Rowland, Molina, Crutzen) figured out that these molecules do destroy ozone, and linked them to observed "ozone holes," mostly found over Antarctica (but not exclusively). Somehow governments from around the world actually got together and ratified the Montreal Protocol in 1987, strengthened it in London in 1990, and CFCs should be eliminated completely by 2010. They'll still be in the atmosphere and ocean, but slowly they will disappear.
Okay, I won't do a review of the greenhouse effect. Suffice to say that greenhouse gases absorb infrared radiation, which essentially trap energy in the atmosphere, warming it. There are six main greenhouse gases (not including water vapor), and the two most important are carbon dioxide (CO_2) and methane (CH_4). The new report says that the replacements for CFCs are also "heat trapping gases." Okay, that is bad news, but the amount of that material must be miniscule compared to carbon dioxide. The response should be an investment in finding more suitable replacements for these materials, and as pointed out by UN Environment Program spokesperson Michael Williams, proper treatment of the currently used materials:
"'What you can do is prevent leaks. You can make sure that when these substances need to be replaced or when the equipment is being thrown out that they are not simply being vented into the atmosphere. That they are destroyed afterwards - contained and destroyed,' he said. 'We also need to have more research on some of the emerging technologies where there could be gases that do not have this problem, where they could be good for both the ozone and the climate change. And, that obviously will be the long-term solution.' "
While this is a problem that should be addressed, we can not lose sight of the big picture. The flux of carbon dioxide into the atmosphere must be reduced before we do irreparable harm to the climate system.