| | 2002 will be the second warmest of last 24 years(12/13/2003)With December temperatures being influenced by an El Nino Pacific Ocean warming event, 2002 will go into the record books as the second warmest year of the past 24, according to data analyzed by scientists at The University of Alabama in Huntsville (UAH). It will also be only the second calendar year during that time in which all 12 months saw global average temperatures warmer than seasonal norms. Through the first eleven months of 2002, temperatures in the lowest layer of the atmosphere averaged more than 0.2 degrees Celsius (more than 0.35 degrees F) warmer than seasonal norms. Temperatures through the first half of December were also more than 0.2 C warmer than seasonal averages. "With an El Nino driving temperatures through December, there's very little chance that things are going to cool off," said Dr. John Christy, director of UAH's Earth System Science Center. The ongoing 16-month string of warmer than average temperatures has pushed the long-term global climate trend upward to 0.07 degrees C of warming per decade since January 1979. If that trend continued for a century, it would mean a global warming of 0.7 degrees C -- about 1.25 degrees Fahrenheit. "While part of that warming can probably be attributed to humaninfluence, including the release of greenhouse gases into the atmosphere, a warming trend this small is still well within the bounds of natural climate change," Christy said. "We don't really know enough about the climate to say with any confidence how much of this warming is natural and how much is caused by human activities. "Earth's climate has changed dramatically several times during the past several thousands of years without human influence. There is no scientific reason to believe that the climate has permanently stabilized and won't change again." The warmest year in the past 24 was 1998, when the "El Nino of the century" pushed the yearly global temperature more than 0.47 degrees C warmer than average. The "hottest" month in the 24-year record was April 1998, with a global average temperature 0.75 C (1.35 degrees F) warmer than seasonal norms. The third warmest year was 1987, with an average global temperature that was 0.13 C warmer than average. The coldest year in the dataset was 1984, when global temperatures dipped more than .25 C below norms. As part of an ongoing joint project between UAH, NOAA and NASA, Christy and Dr. Roy Spencer, an ESSC principal research scientist, use datagathered by microwave sounding units aboard NOAA satellites to get accurate temperature readings for almost all regions of the Earth. This includes remote desert, ocean and rain forest areas for which reliable atmospheric climate data are not otherwise available. The satellite-based instruments measure the temperature in the atmosphere from the surface up to an altitude of about eight kilometers above sea level. Using that data, they have created a global climate dataset going back to January 1979, when the first satellite microwave sounding unit went into service. During that time, there have been 12 years warmer than norms and 12 cooler. The calendar year average global temperature anomalies since 1979, listed from warmest to coolest are: 1998 +0.471 2002 +0.207 1987 +0.130 1988 +0.129 1991 +0.124 2001 +0.122 1980 +0.113 1990 +0.094 1995 +0.088 1981 +0.077 1983 +0.052 1997 +0.011 1996 -0.014 1999 -0.022 2000 -0.034 1979 -0.048 1994 -0.064 1989 -0.085 1986 -0.113 1982 -0.128 1985 -0.179 1993 -0.192 1992 -0.220 1984 -0.253 -- 30 -- For more information: Phil Gentry, (256)824-6420 John Christy, (256) 961-7763 |
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