THE VIRGINIAN-PILOT
Copyright (c) 1995, Landmark Communications, Inc.
DATE: Saturday, May 20, 1995 TAG: 9505190064
SECTION: DAILY BREAK PAGE: E1 EDITION: FINAL
SOURCE: BY JAMES SCHULTZ, STAFF WRITER
LENGTH: Long : 119 lines
GLUB, GLUB.
That's the sound of the East Coast disappearing under a swelling ocean once the polar ice caps melt. Or maybe it's the noise of Dutch dikes breaking from one too many floods, or of New Orleans or Galveston or Miami being swallowed whole by a storm surge after a monster hurricane.
Or just maybe it's the embarrassed reaction of greenhouse effect doomsayers, who were warning just a few years back of submerged shorelines, ruined crops and untold dead plants and animals.
Because, according to the latest scientific evidence, climate catastrophe is on indefinite hold.
``The world won't end in a greenhouse oven,'' said Irving M. Mintzer, a senior research fellow at the Center for Global Change at the University of Maryland. ``It's a more complicated story than that.''
In the past year, the science of climate change has entered a new phase, one revealing a complex web of action, reaction and interaction. Key to the better understanding comes courtesy of sophisticated satellite observations of everything from planetary temperature to the extent and nature of atmospheric pollution.
``We're finally getting a global perspective,'' said Jack Fishman, a senior atmospheric scientist at NASA Langley Research Center in Hampton. ``The problem with all this stuff is that you have cycles embedded in cycles embedded in cycles. You don't know if what you're looking at is dependent on something like sunspot fluctuations - a 22-year cycle - or a trend on top of that cycle. That's the whole problem of climate research.''
Complicating the climate picture four years ago was the eruption of Mount Pinatubo, which sent dust and sulfuric acid droplets more than 15 miles into the stratosphere. At first, the debris meant little more than spectacular sunsets, but eventually the mix acted as a sort of planetary umbrella, reflecting solar radiation back into space and cooling planetary temperatures.
The debris has since been cleansed from the atmosphere. However, a recently detected rise in sea levels worldwide may be the result of temperatures rebounding to their pre-Pinatubo levels.
Climate scientists have yet to figure out the precise interplay between the planet's vast oceans and the sphere of air that surrounds them. What they do know is that the world has, indeed, warmed up, but very slightly - just under 1 degree Fahrenheit over the past 150 years - an increase that many believe to be well within normal variation.
Still, human activity is suspected of having caused at least some of that warming. In particular, massive amounts of heat-trapping carbon dioxide have entered the atmosphere in the past several decades as industrial activities have increased. So-called biomass burning of timber, grasslands and agricultural waste are also thought to have contributed.
In the Northern Hemisphere, the modest upswing in temperature has led to warmer nights, slightly shorter winters and slightly earlier springs and summers.
Complicating the picture is an apparent increase in cloudiness, which has produced an offsetting cooling effect. Also slowing the predicted temperature rise, ironically, are certain pollutants produced by cars, factories and the aforementioned burning.
``The global and local response to warming appears to be relatively benign,'' said Patrick J. Michaels, an associate professor of environmental sciences at the University of Virginia and the Virginia state climatologist. ``Where are the bodies? Where are the crop yield declines? In 1995, the climate models are being adjusted with compensations called heretical five years ago.''
Michaels, a vocal and longtime critic of what he has called ``arguments of doom and gloom,'' is vehemently dismissive of studies he believes selectively ignore the latest findings. He also believes it would be economic folly to change the way energy is produced or used on the basis of suspect warming theories.
``Everyone agrees there has been some warming and that we're right on the edge between a natural variation and something manmade,'' Michaels said. ``The fact the Earth isn't significantly hotter means that the warming is likely to be spaced out over a much longer period: 3.6 degrees Fahrenheit over 100 years. Is that a disaster? No!''
It's not what's happening now but what could happen later that sets some scientists to fretting. The University of Maryland's Mintzer, for instance, would like to see carbon dioxide and pollutant levels reduced worldwide.
He likens the situation to reports of a washed-out bridge. Whether or not the bridge is actually washed out isn't the point, Mintzer contends. Would a motorist, he asks, slow down or speed up to avoid calamity?
``If certain trends continue and carbon dioxide levels double, the warming that is expected to come sometime in the middle of the coming century will be significant and quite dangerous,'' Mintzer said. ``It's not the absolute level but the rate of increase that could seriously harm ecosystems and humans. The warming could be accompanied by severe weather events.''
That's just not so, counters a new report entitled ``Changing Weather?'' Produced by Accu-Weather Inc., a private forecasting firm in State College, Pa., the manuscript is a summation and commentary on climate-change research.
``We have found no convincing evidence that the number and intensity of extreme weather events has increased in recent years,'' assert authors Norman J. Macdonald and Joseph P. Sobel . ``Indeed, were global warming to take place, it is unlikely that potentially dangerous storms, such as hurricanes, would increase in number or intensity.''
Hurricanes bother Langley scientist Jack Fishman less than ignorance - what he and his colleagues have yet to discover. No one in the 1970s, Fishman points out, ``in their wildest imagination'' would have predicted a continent-hugging ozone hole that developed over Antarctica at the South Pole. But the hole did develop, and manmade chemicals were implicated in its creation.
As a result, the harmful substances in question are being phased out of existence.
``With a system as complicated as the Earth's, you have to be cautious,'' Fishman said. ``The ozone hole showed me there is some kind of threshold beyond which a whole new system takes over. That's what we need to worry about.
``I do agree with Pat Michaels. It's not gloom and doom. I believe the change will be gradual. We will adapt and, in the long haul, it won't be painful. But there are things out there we just don't know.'' ILLUSTRATION: Color staff illustration by Sam Hundley
by CNB