
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: MONDAY, April 16, 1990                   TAG: 9004160059
SECTION: VIRGINIA                    PAGE: A3   EDITION: STATE 
SOURCE: Associated Press
DATELINE: CHARLOTTESVILLE                                LENGTH: Medium

WARMING CALLED BENIGN

Acid rain has helped slow global warming but provisions in the Clean Air Act designed to reduce carbon dioxide in the atmosphere could speed up the process, Virginia's state climatologist says.

"The apocalyptic predictions of global warming apparently were off target," said Patrick J. Michaels, an expert on acid rain and global warming. "The signal that we see in the climate, which may be the greenhouse signal, may be a very benign one rather than the apocalypse that people seem to hold so dear."

Michaels said water molecules adhere to airborne sulfates, increasing the world's cloud cover and acting as a buffer against the greenhouse effect.

"Based purely on the measured increase of carbon dioxide, the Earth should have warmed about 2 degrees Celsius in the past 100 years," he said. "In fact, the atmosphere has warmed less than half a degree Celsius."

"By continuing to burn the high-sulfur coal blamed for acid rain, industrialized nations may actually be protecting the Earth from further warming," he said. "One problem for policy-makers is that the Clean Air Act is forcing a reduction of high-sulfur emissions."

The cloud-forming role of sulfates also may explain scientific observations that nighttime temperatures are rising slightly around the globe, while daytime temperatures have remained fairly constant, Michaels said.

"What propels the greenhouse apocalypse view," he said, "is that the evaporation rate on the Earth's surface increases if the temperature increases, causing rainfall to evaporate more quickly and leave the land drier and therefore less productive. Warming at night contradicts the theory about an impending greenhouse disaster.

"If the warming is at night, you don't raise the evaporation rate - what you wind up with is increased rainfall and a longer growing season. That's hardly the apocalypse," Michaels said. "In fact, it's the other way around."

If confirmed, the new data indicates it may be time for legislators to reassess efforts to restrict air pollution, he said.

"People say the Clean Air Act is expensive, and it is," he said. "If, in fact, the cost of the Clean Air Act is to reduce the buffering on global warming that's occurring, the cost of the Clean Air Act is astronomical.

"So what are we supposed to do," Michaels said, "produce acid rain to keep it from warming up? I don't know, but I will tell you one thing. I have not met anyone who knows this problem who thinks we are going to prevent - short of World War III or cold fusion working - the effective doubling of carbon dioxide in the atmosphere. It seems almost unstoppable."

by CNB