Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: FRIDAY, April 1, 1994 TAG: 9404010172
SECTION: NATIONAL/INTERNATIONAL PAGE: A9 EDITION: METRO
SOURCE: Associated Press
DATELINE: WASHINGTON LENGTH: Medium
William Chameides, director of Earth and Atmospheric Sciences at Georgia Tech, said a mathematical projection suggests that increasing ozone and smog pollution eventually will damage plants enough to cause a significant drop in crop yields in areas that produce much of the world's food.
In a study to be published today in the journal Science, Chameides said that about 60 percent of the world's damaging air pollutants are produced by North America, Europe and the China-Japan region of Asia. About 60 percent of the world's food is produced in these areas.
Chameides said that when ozone reaches 50 to 70 parts per billion in the atmosphere, it begins to affect plants' vigor. Chronic exposure to such levels can reduce agricultural production, perhaps as much as 5 percent, he said.
In some parts of the world, such as China, damaging levels of pollution could become chronic by 2025.
Though the crop reduction may be only a few percentage points, said Chameides, the damage could come as a growing world population puts extreme demands on the food supply. A computer model developed by Chameides and his co-authors shows the effect could be profound.
"The margin between supply and need will be more narrow then, so just a small decline in yields could be important," Chameides said.
China, he said, is self-sufficient for food, but if it one day has to start buying on international markets, it could have a powerful effect on the cost and availability of food.
Chameides said his model is based on mathematical projections that can change as a result of scientific advances or government actions affecting crops.
by CNB