The air up there
In the wake of Sept. 11, and the U.S. war on terrorism, a number of major stories have shifted to the background. In the case of the ozone layer, unfortunately, no news does not mean good news.
Recent studies indicate the hole in the ozone layer, which was first discovered in the late 1970s and is most pronounced over the Antarctic region, could be with us for many years to come.
Ozone molecules are actually found in two separate regions of the Earth’s atmosphere. About 90 percent of all ozone is found in the stratosphere, the area of the atmosphere from six to 30 miles above the earth. Ozone here absorbs harmful ultra-violet rays from the sun, which in turn heats the stratosphere and helps to maintain global weather patterns. The hole in the ozone increases and decreases in a cycle related to the weather cycle, with the hole in the Antarctic region reaching its largest size in Spring.
The other 10 percent of ozone is found lower in the atmosphere, and is one of the main components of smog. This level of ozone has a toxic effect on plants and humans.
Despite an international treaty signed in 1987 that banned ozone-destroying chemicals such as the chloro-flouro-carbons (CFCs) most commonly found in coolants for refrigerators and freezers, the ozone layer over some regions continues to decline. Last month, at a closed session of the World Climate Research Program in Australia, a prominent American scientist, Susan Solomon, predicted to fellow scientists that the hole in the ozone layer could cause the destruction of the Antarctic ice shelves, according to the March 27 issue of Australian Financial Review.
That very day, in an event of unprecedented scale, a huge section of the Larsen Ice Sheet in Antarctica, disintegrated, splitting into hundreds of icebergs, each larger than Manhattan Island.
According to Solomon’s theory, the loss of ozone in the stratosphere has caused the upper and middle layers of the atmosphere to cool to the lowest temperatures ever recorded there. This in turn has affected the low pressure areas over the North and South Poles. Formerly, weather patterns there circulated in what she called a “lazy vortex,” but Solomon believes the vortices have become smaller, faster and colder. In other words, the cold air in Antarctica has been confined to the center of the continent, and the outer edges (where the Larsen Ice Sheet is located) are subject to warmer weather patterns.
A recent study in Argentina, which is near enough to Antarctica to be affected by the hole in the ozone there, shows there has been a 66 percent increase in skin cancer in the city of Puntas Arenas from 1987 to 2000, according to an April 2, Boston Globe article.
Another recently released study conducted at the University of Southern California drew a connection between the surface-area ozone contained in smog and the occurrence of asthma in children. In the USC study, the most athletic children in Southern California’s smoggiest communities were found to be three times as likely to develop asthma than their peers who did not exercise.
Robert Gillies, assistant professor in the plants, soils and biometeorology department at Utah State University, said the photochemical smog of which ozone is a major component was increasingly becoming part of life in Cache Valley, especially in winter.
“The smog is a chemical soup that is really not very nice,” Gillies said. “It won’t be long until there are ‘no burn’ days in Cache Valley.”
Gillies said it was often difficult to determine whether changes in the global climate were part of natural processes or the result of human pollution. He said most climatologists would agree the human population has reached a point where as a species we are having a major impact on the planet’s natural processes, including the global climate. The problem, he said, there isn’t enough knowledge to completely understand those processes or what the long-term effects of the pollution will be.
For more information on the ozone layer, visit the Web site www.ozonelayer.noaa.gov.