Weather Whys; Global Warming

This is weather-wise. For over a decade, there's been widespread concern about the possibility of a major global warming due largely to increased concentrations of certain gases in the atmosphere. But despite all the concern, scientists have found it difficult to demonstrate that such an effect is taking place. Many are still cautious, saying they can't be certain the warming is occurring now, or that it will ever occur. A group of British scientists have found, though, that six of the seven warmest years in well over a century have occurred since 1980. They estimate there's been a global warming of one-half-degree Celsius over the last hundred years. And while that may not seem like much, in climatological terms, it's fairly significant. And 1990 proved to be no exception. The British researchers say last year the average surface temperature over the globe was the highest it had been in a century.

That result is even more interesting when you consider another climatological factor. El Niño is a warming of tropical waters which occurs every few years, and some feel it may be responsible for at least some of the warmth seen in the 1980s. So it's hard to determine if increased concentrations of trace gases caused any increase in the global temperature during that time. But there was no El Niño in 1990, so that makes the warming seen last year even more convincing. However, even if the data does support the idea of a warming trend this century, it's important to note there have been even warmer periods at other times in the past thousand years. We'd like to know what you think of Weatherwise. Please write us at Weatherwise, K-G-O-U radio, the University of Oklahoma, Norman, Oklahoma, 73019-025-0. Weatherwise is made possible by a grant from the National Science Foundation.

I'm Drew Barlow.