Scientists Question Global Warming Theory Climatologists Say Broad Theory Is Too Simplistic to Explain Temperature Drops in Industrialized Areas and Other Complex Climate Changes

Article excerpt

YOU don't have to be a weather scientist to see what's wrong with the global-warming theory. You only have to look around on a hazy day.

Man-made aerosol particles - so tiny a million of them could crowd on to a pin head - are forcing scientists to adopt a new view of what changes Earth's climate.

Carbon dioxide (CO2), released by burning fossil fuels, and other so-called "greenhouse" gases create the effect of trapping heat in the atmosphere. But cooling by the aerosols offsets this warming influence in industrialized regions.

Ironically, these particles also are produced by burning fossil fuels.

"The term `global warming'... couldn't be farther from the truth," says atmospheric chemist Robert Charlson at the University of Washington in Seattle. He explains that the term is misleading because it is based on averages such as the average annual temperature of Earth.

Yet, Professor Charlson observes: "We're not concerned with the average temperature of the planet. We're concerned with rainfall in Kansas." Climate change, he adds, is non-uniform with significant regional differences.

Climate analyst Jeffrey Kiehl with the National Center for Atmospheric Research in Boulder, Colo., has charted those differences.

His map (reproduced here) shows regional cooling - not warming - for large parts of the industrialized Northern Hemisphere. Scientists, Dr. Kiehl says, now recognize that man-made climate change is not "just a greenhouse effect." They see that "it's a regional effect... strongly tied to local {aerosol} sources."

Charlson sees "a revolution in the way certain segments of the {research} community think about climate change," calling it a "paradigm shift." Global warming is too simplistic a concept to do the job.

Charlson explains that the "paradigm shift" lies in realizing that the influences forcing climate change are physically and geographically complex. Moreover, he adds, "The whole story isn't in yet."

Here's what's going on. Basically, greenhouse warming is a good thing. Without naturally occurring greenhouse gases - mainly water vapor and CO2 - Earth would be too cold to support life. However, human activity - mainly burning coal, oil, and natural gas - has loaded the air with additional greenhouse gases. Atmospheric CO2 concentration has risen from a preindustrial 280 parts per million (ppm) to the 1990 value of 353 ppm.

If that CO2 increase is projected into the future, using today's relatively crude computer-based climate models, the average planetary temperature rises several degrees. That's global warming.

Enter the aerosols. …