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New Data Points to Reality of Climate Change Recent studies of atmospheric surface temperatures and ocean temperatures support the claim that global warming is occurring and will probably bring major climate changes in coming years. By GSReport Start Date: 1/25/00 New scientific studies announced in mid-January, 2000, add weight to the growing prospect of climate change. One study, released on Jan 13 by the National Academy of Science's National Research Council (NRC), declared that Earth's surface temperature has warmed by 0.7 to 1.4 degrees Fahrenheit in the last century, and that fully half of that warming (0.5 to 0.7 degrees Fahrenheit) has occurred within the last 20 years. A separate set of findings, announced on Jan 19 by scientists at NASA's Jet Propulsion Laboratory in Pasadena, suggests that a new pattern of water temperatures may be occurring in the Pacific Ocean. Satellite data shows higher than average water temperatures in the north, west and south Pacific, forming a horseshoe pattern of warm water around a wedge of colder than normal water off the west coast of South America. This pattern is characteristic of the so-called La Nina condition that has strongly affected weather across much of the Western Hemisphere for several years. However, scientists analyzing the new satellite data say this pattern may be part of a longer cycle, called the Pacific Decadal Oscillation, which could persist for decades. Both sets of findings lend credence to the supposition that the Earth could experience large-scale climate changes in coming years. But members of the NRC panel, while confirming the evidence of warming near the Earth's surface, also cautioned that very little warming had occurred at higher levels of the atmosphere. And, they said, it is still too soon to tell why the Earth's surface is warming and whether the rate of warming will persist. "The differences between surface and upper-air trends in no way invalidates the conclusion that the Earth's temperature is rising," said John Wallace, panel chair and professor of atmospheric sciences at the University of Washington in Seattle. "But the rapid increase in Earth's surface temperature over the past 20 years is not necessarily representative of how the atmosphere is responding to long-term, human-induced changes, such as increasing amounts of carbon dioxide and other greenhouse gases." Similarly, Dr. William Patzert, an oceanographer at JPL, said that it was still too soon to declare that a Pacific Decadal Oscillation is underway. But, he said, the new satellite data on Pacific ocean temperatures "tells us there is much more than an isolated La Nina occurring." La Nina ocean conditions in the last two years are considered to be the cause of increased precipitation in the Pacific Northwest, and excessive dryness in the U.S eastern and southwestern states as well as much of Mexico and parts of Central and South America. If the Pacific Decadal Oscillation locks in La Nina-like conditions, below-average rainfall and above-average temperatures could persist for several decades in California, the U.S. southwest, Mexico and other affected regions, with potentially severe economic impacts. La Nina-like conditions could also contribute to more and stronger hurricanes in the Atlantic and Caribbean regions. Higher average surface temperatures around the world could also have major impacts on long-term climate, changing rainfall patterns and producing more frequent and more severe storms worldwide. During 1999, a number of the most powerful storms ever recorded hit many parts of the world, including the most powerful tornado ever seen in the U.S., the most powerful cyclone ever seen in Australia, one of the most powerful cyclones ever seen in India, and some of the most devastating wind storms ever seen in Western Europe. In related news, the French government, still recovering from "storms of the century" that occurred in late December, announced on Jan 19 a series of measures aimed at cutting greenhouse gas emissions by 10 percent by the year 2010 to meet France's obligations under the 1997 Kyoto protocol on climate change. French Prime Minister Lionel Jospin said the government had taken pains to ensure deep cuts in greenhouse emissions without sacrificing strong economic growth. The French measures include an energy consumption tax on some industries; incentives to produce more fuel-efficient vehicles, expand mass transportation and improve energy efficiency in buildings; and promotion of research on non-polluting alternative energy systems. But French Environment Minister Dominique Voynet said that the government's plan might be insufficient to meet stated targets. And representatives of environmental groups expressed doubt that the government plan would be fully implemented. All industrial nations of the world face the difficult challenge of defining and implementing programs aimed at mitigating potential climate change, even before scientists fully agree on the mechanism and extent of global warming. But new data consistently suggest that waiting for complete understanding could mean waiting far too long.
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