Contact:  Rick Peterson, Manager of News Services, 920/832-6590
For Immediate Release
October 17, 2000

Global Cooling?  Lawrence Lecture Examines Effect of Carbon Dioxide on
Upper Atmosphere


     APPLETON, WIS. -- While any stint of unseasonably warm weather
today fuels concerns about global warming, scientists also believe the
same factors contributing to the rising temperatures on Earth are having
the opposite effect above it. 
     Kate Kirby, asssociate director of the atomic and molecular physics
division at the Harvard-Smithsonian Center for Astrophysics in
Cambridge, Mass., presents "Global Cooling in the Earth's Upper
Atmosphere: Why? And Should We Care?," Tuesday, Oct. 24 in a Lawrence
University science hall colloquium.  Kirby's address, at 11:10 a.m. in
Science Hall, Room 102, is free and open to the public.
     Carbon dioxide and other so-called "greenhouse" gases trap infrared
radiation  in the lower atmosphere, producing a global warming effect.
But in the upper atmosphere -- more than 10 miles above the Earth's
surface -- carbon dioxide acts as a coolant and the build-up of the gas
substantially lowers temperatures at this level.  In her address, Kirby
will discuss the reasons for the cooling and its potential impact on
life on Earth.