CHAMPAIGN, Ill. -- Some of the chemicals being phased out to protect the ozone layer offer offsetting benefits, such as reducing global warming, a University of Illinois researcher says.
"By independently addressing the issues of ozone depletion and global warming, we are jeopardizing desirable options for one effect based on lesser -- or even inconsequential -- impacts on the other," said Don Wuebbles, director of the Environmental Council at the U. of I. and a professor of atmospheric sciences. "We need to stop looking at these issues as though they are separate from one another, and start considering them together when we determine environmental policy."
In the Nov. 7 issue of the journal Science, Wuebbles and colleague James Calm, an engineering consultant in Great Falls, Va., write that the regulatory actions on certain chemicals -- imposed by both the Montreal Protocol and the U.S. Clean Air Act to protect the ozone layer -- will have little impact on stratospheric ozone while contributing unnecessarily to global warming.
"Most of the chemicals responsible for ozone depletion are also greenhouse gases," Wuebbles said. "Chlorofluorocarbons [CFCs], for example, tend to be severe offenders for both the depletion of ozone and for global warming. The need for their regulation is unambiguous."
But there are other industrially important chemicals that fall into the gray area. "Some hydrochlorofluorocarbons [HCFCs], for example, have very short atmospheric lifetimes and mostly decompose before reaching the upper atmosphere," Wuebbles said. "Effects on ozone depletion from some of these compounds are likely to be negligible. Nevertheless, they are still being tightly regulated and eventually the intention of the rulings is that they be banned entirely."
One such chemical, HCFC-123, is a high-performance refrigerant commonly
used in the cooling systems of large buildings. Some of the intended replacements
for HCFC-123 not onl
'"/>
Contact: James E. Kloeppel
kloeppel@uiuc.edu
217-244-1073
University of Illinois at Urbana-Champaign
4-Dec-1997