1997 Ranks as Warmest Year of the Century

The year 1997 was the warmest of the 20th century, the federal government announced Thursday, fueling fears that the so-called greenhouse effect is contributing to global warming.

The new figures are even more worrisome, in the view of many scientists, when combined with other data showing that the warmest five years of the century--when such recordings began--have all occurred since 1990.

“Are there reasons to be skeptical that greenhouse gases are having an impact? No. There are no reasons to be skeptical,” said Tom Karl, the senior scientist of the National Oceanic and Atmospheric Administration’s National Climatic Data Center.

President Clinton seized on the new data, saying at a fund-raising event in New York: “We need a national consensus to do something on global warming. It is significant, and what we need is an understanding that we can grow the economy and still preserve the environment.”

His administration is embarking on what is likely to be a difficult campaign to win Senate approval of an international agreement, negotiated last month in Kyoto, Japan, to reduce emissions of carbon dioxide and five other gases.

These gases, many scientists say, trap heat in the atmosphere much the way a greenhouse roof holds in the sun’s warmth.

Still, the announcement of the new temperature data prompted skepticism from longtime critics of the theory that global warming is real and that it is being brought on by such centerpieces of modern life as the automobile, refrigerators and energy-demanding televisions.

“The surface of the ocean has warmed, obviously the effect of El Nino,” the periodic warming of ocean waters that wreaks havoc--as it has for the past several months--with global weather patterns, said S. Fred Singer, an atmospheric physicist and president of the Science and Environmental Policy Project, an organization of mostly retired academics that has questioned the evolving theory of global warming.

“El Nino will last only a year. I’d bet next year will be much cooler. One year does not make a trend,” he said.

As for the steadily warming temperatures reported throughout the decade, he said they were based on data contaminated by recordings made at airports close to cities that reflect the “heat island” effect that warms urban areas where cooling shade trees, lawns and meadows are lacking.

According to the National Climatic Data Center’s figures, the mean temperature of the Earth’s surface, based on readings on land and at sea around the globe, was 62.45 degrees Fahrenheit, an increase of three-quarters of a degree over the mean temperature during the previous three decades.

In 1990 and 1995, the reading was 62.30 degrees, the highest recorded this century, before last year. On land, the 1997 figure was 58.06, down from the 58.29 figure in 1995 and the modern record of 58.31 in 1990; at sea, the 1997 figure was 64.25, the highest yet recorded.

While the yearly variations may appear minuscule, climatologists consider them significant because an increase of barely two degrees could introduce such feared results of global warming as flood-inducing higher sea levels and drought-producing shifts in weather patterns.

Indeed, during the most recent Ice Age about 18,000 years ago, scientists have calculated that the Earth’s temperature was perhaps no more than 10 degrees cooler than now.

Karl and other climatologists, such as Stephen Schneider of Stanford University, acknowledge that one year does not make a trend.

This is why the facts that the last decade produced the warmest five years of the century, and that the warmest 10 years over land have all occurred since 1981, give them pause.

While the administration was making the new data public, Vice President Al Gore, in a satellite-fed speech from Washington to the International Consumer Electronics Show in Las Vegas, announced that 11 electronics companies will produce reduced-energy televisions and VCRs.

Gore said that by reducing energy demands, the newly designed products will lessen carbon dioxide emissions by 5 million tons a year--equivalent, he said, to “eliminating the pollution from more than 1 million cars.”