By Jim Lobe
WASHINGTON, Jan 8 1998 (IPS)

The year 1997 was the warmest on record, as measured by land and ocean surface temperatures, according to top U.S. government scientists. Global temperatures last year increased by an average of .083 degrees Celsius over the previous record year, 1990.

The greatest increases were recorded in the eastern Pacific, the northeastern Atlantic, and much of northern and east Asia, according to data released Thursday by the National Climatic Data Center of the National Oceanic and Atmospheric Administration (NOAA).

The scientific findings are certain to bolster warning that the Earth’s climate is warming and computer projections show that the buildup in the atmosphere of “greenhouse gases” could heat up the global climate by between 1.0 and 3.5 degrees Celsius during the next 100 years, NOAA officials said.

The future emission of such gases, which are produced by burning fossil fuels, was the subject of a tentative international agreement reached last month in Kyoto, Japan. It requires 38 industrialised nations to reduce their emissions below 1990 levels by about six percent overall between 2008 and 2012.

The pact faces substantial opposition in the United States, the world’s biggest producer of greenhouse gases. Critics, dominated by oil, gas, and coal interests, argue that fast-industrialising poor countries, particularly China, India, and Brazil should also be bound by the treaty and that substantial reductions in U.S. emissions will have a devastating effect on the economy. They have also questioned the accuracy of the computer projections.

NOAA’s Senior Scientist, Tom Karl, pointed out that the record- breaking conditions in 1997 continue a pattern of very warm global temperatures and nine of the past 11 years have set new records. With the new data factored in, temperatures taken since 1900 show that the warming now exceeds 0.5 degrees Celsius per 100 years, with land temperatures increasing at a somewhat faster rate than ocean surface temperatures.

Based on that finding, Karl told a news conference, “It is likely that the sustained trend toward increasingly warmer global termperatures is related to anthropogenic increases in greenhouse gases.” He added that the new findings are consistent with computer models that have predicted warming due to greenhouse emissions.

NOAA also released new data showing that the Earth’s higher latitudes have received increasing amounts of rain and snowfall since the beginning of the century, while the tropical zones have received decreasing amounts of rainfall over the same period. According to Elbert Friday, the Centre’s Assistant Administrator for Oceanic and Atmospheric Research, those trends also conform to predictions made by computer models based on the likely impact of greenhouse emissions on the global climate.

Karl said that the mean land temperature for 1997 fell short of the 1990 record. Despite that, 1997 was still one of the five warmest years over land since 1880. Including 1997, he said, the top ten warmest years over the land have all occurred since 1981.

Ocean temperatures during 1997, on the other hand, were the warmest ever. They exceeded the previous record warm years of 1987 and 1995 by about .165 degrees Celsius.

That increase was related in major part to the El Nino effect, the global weather pattern that begins with a natural warming of the eastern Pacific around Indonesia. The 1997 El Nino was reputed to be the strongest on record.

El Nino spurs greater than normal precipitation along most of the Pacific coastline of the Americas, the Horn of Africa, and parts of the Indian Ocean. It also is associated with drought conditions in much of Southeast Asia, northeastern South America and parts of the Caribbean and southern Africa. The relationship between El Nino and global warming is a matter of considerable controversy.

“Global warming definitely has an influence on El Nino,” said Friday, “but it’s not clear what it is.” One school of thought was that global warming is increasing the frequency of El Nino but “the jury is still out on that,” he said.

Even discounting El Nino’s influence in warming ocean temperatures in various parts of the world, 1997 would still have been among the top ten warmest years on record, according to Karl, who ten years ago was counted among the sceptics about the global warming theory. “A lot more pieces (of the puzzle) are fitting (the models) than not fitting,” he said.

According to a NOAA map of global temperatures anomalies recorded during 1997, the greatest above-average increases in temperature – two degrees Celsius or more – occurred in West Europe, the west coast of the Americas, the Caribbean, sub-Arctic regions, West and southeastern Africa, southern India, and northern southeast Asia.

Lower-than-normal temperatures, on the other hand, were recorded in eastern North America, the Black Sea area, northern India and Pakistan, Indonesia and northern Australia. The fact that specific regions of the world were actually cooler than usual does not undermine the general global warming thesis, warned Friday. “Everything we know about it is consistent with natural variability coupled with human impacts,” he added.

Similarly, the new findings about precipitation over the past century is consistent with the modeling done for global warming. The precipitation map released Thursday shows that most of Central America, the Caribbean, Chile, northern South America, an entire band of Africa stretching from the equator northwards to the Sahel, most of Indonesia and peninsular Southeast Asia, and the western Pacific, including Japan, have all experienced progressively less rainfall since 1901.

By contrast, precipitation has increased over the same period in most of North America, the Nordic countries, the Atlantic coast of Europe, all of northern Russia, central Asia, Australia, and eastern South America, according to NOAA.

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