WASHINGTON -- Researchers at NOAA's National Climate Data Center
(NCDC) have found evidence that the rate of global warming is
accelerating and that in the past 25 years it achieved the rate
of two degrees Celsius (four degrees Fahrenheit) per century.
This rate had previously been predicted for the 21st Century.
Writing in the March 1 issue of Geophysical Research Letters,
Dr. Thomas R. Karl, Director of NCDC, and colleagues analyze
recent temperature data. They focus particularly on the years
1997 and 1998, during which a string of 16 consecutive months
saw record high global mean average temperatures. This, Karl
notes, was unprecedented since instruments began systematically
recording temperature in the 19th Century. During much of 1998,
records set just the previous year were broken. Karl and his
colleagues conclude that there is only a one-in-20 chance that
the string of record high temperatures in 1997-1998 was simply
an unusual event, rather than a change point, the start of a new
and faster ongoing tr