CFCs: A larger greenhouse role



The extreme sensitivity of the atmosphere to human intervention is demonstrated by new evidence of the rapidly expanding role of chlorofluorocarbons in greenhouse warming.

A new study indicates that CFCs, present in just a few parts per billion in the atmosphere, are responsible for fully a quarter of greenhouse warming over the last decade, more than previously estimated. Projections suggest that if CFC production had not declined after 1974 the compounds would today be the largest single trace gas cause of climate change, responsible for nearly as much eventual warming as carbon dioxide, methane, and nitrous oxide combined.