Planet posts temperature record for 1997.Last year, Earth squeaked past the previous record high for globally averaged temperatures, continuing a balmy trend that has made this decade the hottest in more than a century of temperature data, report three teams of climate scientists.
"All of us are pretty happy with the agreement of the different methods," says Thomas R. Karl Thomas R. Karl (Born 22 November 1951, Evergreen Park, Illinois) is the director of the National Oceanic and Atmospheric Administration’s National Climatic Data Center. of the National Climatic Data Center (NCDC) in Asheville, N.C., who announced his group's findings last week. "There are differences [among the teams' findings], but they are small."
Earth's land and ocean surface last year was 0.42 [degrees] C warmer than the long-term average of 16.5 [degrees] C for the reference period 1961 through 1990, says Karl. The NCDC team analyzed data from more than 5,000 land stations and from water temperature readings collected by satellite sensors, buoys, and ships.
1997 came in almost a tenth of a degree warmer than the previous record years, 1990 and 1995, which were virtually identical in the NCDC data. Researchers play down the differences among these three years because the uncertainties in the figures exceed the gaps between them. The important message, they say, is that 9 of the top 10 warmest years on record have occurred since 1987.
Such evidence adds weight to arguments that humans are altering climate in noticeable ways. It is likely, says Karl, that greenhouse gas greenhouse gas
Any of the atmospheric gases that contribute to the greenhouse effect.
greenhouse gas emissions are playing a role in the sustained upward trend in temperatures.
El Nino helped push Earth's temperature into new territory last year by producing a vast pool of warm water in the equatorial Pacific Ocean. Even without El Nino, however, global temperatures would have remained high. During the first few months of 1997-before El Nino blossomed-the land surface was already quite warm, says Karl.
In contrast to the global pattern, eastern North America North America, third largest continent (1990 est. pop. 365,000,000), c.9,400,000 sq mi (24,346,000 sq km), the northern of the two continents of the Western Hemisphere. stayed cooler than normal last year, as did the eastern Mediterranean and northern India.
In their analysis of global temperatures, researchers at the United Kingdom Meteorological me·te·or·ol·o·gy
The science that deals with the phenomena of the atmosphere, especially weather and weather conditions.
[French météorologie, from Greek Office in Bracknell found 1997 to be 0.43 [degrees] C above average--the highest since they began keeping records, in 1860. Their calculations do not yet include December data, but the value will not change appreciably, they say.
A third study of global temperatures, conducted at NASA's Goddard Institute for Space Studies The NASA Goddard Institute for Space Studies (GISS), at Columbia University in New York City, is a component laboratory of NASA's Goddard Space Flight Center Earth-Sun Exploration Division and a unit of The Earth Institute at Columbia University. in New York New York, state, United States
New York, Middle Atlantic state of the United States. It is bordered by Vermont, Massachusetts, Connecticut, and the Atlantic Ocean (E), New Jersey and Pennsylvania (S), Lakes Erie and Ontario and the Canadian province of , puts 1997 temperatures at 0.40 [degrees] C above the average for the base years 1951-1980.
Although consistent with each other, these surface measurements contrast with satellite readings of Earth's lower atmosphere. The temperature between the ground and an altitude of 6,000 meters last year hovered slightly below the average value for the years 1982 through 1991. In the 19-year record of satellite data, 1997 ranked as the eighth coolest, says John R. Christy of the University of Alabama The University of Alabama (also known as Alabama, UA or colloquially as 'Bama) is a public coeducational university located in Tuscaloosa, Alabama, USA. Founded in 1831, UA is the flagship campus of the University of Alabama System. in Huntsville.
Satellite data indicate that the lower atmosphere has cooled over the last 19 years. However, when Christy corrects for the strong cooling effects of volcanic eruptions volcanic eruptions
discharging of fumes, dust and lava from volcanoes. They have damaging potential in addition to those of being physically overpowering by the lava flow or the ash or dust fallout. and warming effects of El Nino, the satellite trend turns into a warming of 0.07 [degrees] C per decade. The surface has warmed at twice that rate.
Climate scientists are investigating this discrepancy. The two data sets need not agree perfectly, because they measure different parts of the planet. Still, the size and duration of the difference has raised concerns. It is highly unlikely that the atmosphere and surface could behave independently for so long, says NASA's James Hansen For the American politician from Idaho, see Jim D. Hansen. For the American politician from Utah, see James V. Hansen.
James E. Hansen (born March 29 1941 in Denison, Iowa) heads the NASA Goddard Institute for Space Studies .
Last year, a team of researchers reported finding evidence of problems that artificially lowered the satellite temperature measurements Satellite temperature measurements have been obtained for troposphere since 1978. By comparison, the usable balloon (radiosonde) record begins in 1958.
Satellites do not measure "temperature" as such. (SN: 3/15/97, p. 156). Christy counters that these satellite readings agree almost perfectly with balloon readings.