As reported in the April issue of the journal "Environmental Health
Perspectives" (Vol. 111, No. 4), U.S. cities average 10 more hot
summer nights -- classified as above 70 degrees F in the East, South,
and Midwest, and above 80 degrees F in the Southwest -- than they did
40 years ago. Nationwide in the U.S., there has been a 300% greater
rate of warming in cities than in the rural countryside, according to
a study by Arthur DeGaetano, associate professor of Earth and
atmospheric sciences at Cornell University, and Robert J. Allen, then
a research support specialist at the university.
The study, which originally appeared in the November 2002 issue of the
"Journal of Climate", analyzed historical data on daily high and low
temperatures from 361 weather stations across the United States from
1910 to 1996, adjusting for omissions, differences in observation
times and other discontinuities, and using the hottest 10%, 5%, and
1% of all the daily high or low temperatures recorded by a station
over its period of operation.
For the period 1960-1996, the pair found that 75% of stations showed
an average increase in both hot summer days and hot summer nights.
The rate of warming was greatest in the East and least in the central
section. The results also showed that cities are warming at more than
triple the rate of rural locales.
"The ultimate test of man's conscience may be his willingness to
sacrifice something today for future generations whose words of thanks
will not be heard."
- Gaylord Nelson, Earth Day founder