ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Sunday, July 14, 1996 TAG: 9607150082
SECTION: NATIONAL/INTERNATIONAL PAGE: A-2 EDITION: METRO
DATELINE: WASHINGTON
SOURCE: Associated Press
How hot was it? Last year was the hottest year on record, according to NASA's top world temperature taker.
The globe's average temperature for 1995 was an estimated 59.8 degrees Fahrenheit, barely edging out 1990 and about 0.8 degree above the 1950-1980 average. That's according to James Hansen, writing in the June 15 issue of Geophysical Research Letters.
It was Hansen who first brought the threat of global warming to national attention, telling a congressional committee in 1988 that he was ``99 percent sure'' greenhouse warming was under way.
Temperatures are running a little cooler this year, he says, thanks to a slight chilling of the water in the tropical Pacific Ocean.
``But over the next few years,'' he added last week, ``I would, with a pretty high degree of confidence, expect the global temperatures to exceed even the 1995 level.''
Some researchers, however, wonder whether the globe really has begun to overheat. Taking the Earth's temperature isn't as simple as sticking a thermometer in one's mouth.
Even Hansen, while choosing last year as the hottest ever, reports that readings for 1990 and 1995 are so close that their relative rank might vary from one analysis to another because of differences in sampling, measurement errors and various ways the data can be analyzed.
Further, the 1991 eruption of the Mount Pinatubo volcano in the Philippines cast tons of dust into the atmosphere, screening out some of the sun's light and reducing global temperatures for a few years.
``The important point is that the global surface temperature has recovered to about the level of 1990, previously the warmest year of the century,'' reported Hansen, of NASA's Goddard Institute for Space Studies.
A United Nations panel has warned of danger from excessive greenhouse warming, including the threat of damaged crops, rising sea levels, changing storm patterns and a spread of tropical diseases.
Hansen isn't the first to report a hot 1995; but as a pioneer researcher in the area, his report adds weight to other studies.
In January, researchers at the University of East Anglia in England reported that the world's average surface temperature for 1995 was 58.72 degrees Fahrenheit, or 0.7 degree higher than the average for 1961-1990. The previous record temperature was 58.64 degrees in 1990.
The British predicted 1996 will be slightly cooler.
The National Weather Service said 1995 was the second warmest year on record, averaging 52.36 degrees. That estimate, based on land-surface measurements, was 0.18 degree cooler than 1990, the warmest year recorded by the Weather Service.
In April, the World Meteorological Organization weighed in, saying 1995 was the hottest year, with an average surface temperature 0.72 degree higher than in the prior three decades.
The possibility of greenhouse warming has been discussed for years by scientists, and many dissent on whether it has begun.
The theory holds that increasing amounts of carbon dioxide and other industrial gases being added to the atmosphere will trap some heat previously radiated out to space, causing Earth to warm up.
Dissidents such as Virginia State Climatologist Patrick Michaels have questioned whether Earth has really begun to overheat, noting the relatively short period for which accurate temperature records are available.
Weather varies widely from place to place and time to time.
The British data concentrate on land areas, where temperature fluctuates more than over the oceans. Satellite measurements seek to cover the whole planet but go back less than 20 years and focus on the lower-middle atmosphere rather than the surface readings of other records.
In addition, there have been major changes in the mere 100 years records have been kept, with cities growing up and adding heat to sites where readings are taken, and new and relocated thermometers giving different readings that may or may not be comparable with those taken earlier.
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