25 June 2009
On June 22, CSD scientists David Fahey and John Daniel and coauthors published a study on the projected future impact of hydrofluorocarbons (HFCs) on climate. The study, published in the Proceedings of the National Academy of Sciences, finds that HFCs – especially from developing countries – will become an increasingly larger factor in future climate warming. HFCs are used as substitutes for ozone-depleting compounds such as chlorofluorocarbons (CFCs) in applications such as refrigeration, air conditioning, and the production of insulating foams.
Background: The 1987 international agreement known as the Montreal Protocol has gradually phased out the use of CFCs and other ozone-depleting substances, leading to the development of long-term replacements such as HFCs. HFCs are in the "basket of gases" regulated under the 1997 Kyoto Protocol, an international treaty to reduce emissions of greenhouse gases.
Significance: Global use of HFCs is expected to grow in coming decades. Projections indicate that by 2050, HFCs could have a climate change contribution that is 7 to 12 percent of that from carbon dioxide emissions. Today it is less than 1 percent.
Velders G. J.1, D. W. Fahey2, J. S. Daniel2, M. McFarland3, and S. O. Andersen4, The large contribution of projected HFC emissions to future climate forcing Proceedings of the National Academy of Sciences, doi:10.1073/pnas.0902817106, 2009.