Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: TUESDAY, May 15, 1990 TAG: 9005150218
SECTION: NATIONAL/INTERNATIONAL PAGE: A-4 EDITION: METRO
SOURCE: Associated Press
DATELINE: ANNAPOLIS, MD. LENGTH: Medium
Many researchers believe that the carbon dioxide buildup from use of fossil fuels and destruction of forests will raise temperatures at least several degrees during the next few decades.
Some researchers dispute that, however. Their view has been used by the Bush administration to justify a wait-and-see response to the so-called greenhouse effect.
Fakhri Bazzaz, a Harvard University biologist, argued at a Rockefeller Foundation symposium on agricultural research that the carbon dioxide buildup will have a direct effect on farms and forests even if it doesn't raise temperatures.
"The cornfields in Illinois are not independent of the fate of the tropical forests," he said.
While researchers might disagree over the temperature effects of the carbon dioxide buildup, no one disagrees about the carbon dioxide buildup itself.
Several decades of research have shown that carbon dioxide already has increased substantially and is continuing to increase, researchers say.
Bazzaz, who has grown plants in enclosures with air rich in carbon dioxide, has found that the plants grow faster, but that their leaves may be less nutritious.
Leafy vegetables eaten by humans may change their chemistry so much that they will become unpalatable, he said.
The accelerated growth of plants in response to increased carbon dioxide might seem beneficial, but that means increases in weed growth as well as crop growth, he said.
Plants will grow faster only if they get more nutrients from the soil along with the increased carbon dioxide in the atmosphere, he said.
In some circumstances, weeds may be more easily able to overcome crops because the weeds will respond better to the increased carbon dioxide.
by CNB