A Hole in Rush's Argument

"There is no ozone hole!" barks right-wing radio and TV personality Rush Limbaugh, who claims "environmentalist wackos" are behind the effort to ban chloroflourocarbons, and grant-hungry scientists are perpetuating a myth to butter their bread.

Contrary to Limbaugh's opinion are pesky facts, such as those presented this year by Geophysical Institute Associate Professor of Chemistry Dan Jaffe and his colleagues. Monitoring ozone high above Alaska, Jaffe found spring 1995 levels noticeably lower than the average of ozone levels from 1984-1994.

Ozone is important to life on earth because it absorbs ultraviolet radiation from the sun. Unchecked, ultraviolet radiation causes skin cancer and damages ecosystems. Ozone, an unstable molecule of three oxygen atoms, is present throughout the atmosphere. It does much of its protective work in a dense layer from about 15 to 18 miles above the earth. There, ozone molecules intercept ultraviolet radiation and convert it to heat, preventing it from reaching the earth.

Humans destroy ozone. Chloroflourocarbons (CFC's) are manmade chemical compounds used to make foam, refrigeration equipment, and propellants for spray cans and asthma inhalers. When CFC's leak from old refrigerators or the foam pad within the seat you're now sitting on, they eventually drift up to the ozone layer. Once there, CFC's break down to form chlorine. Chlorine reacts with ozone and changes it to oxygen, which doesn't absorb ultraviolet radiation.

The famous ozone hole over Antarctica recurs every spring as CFC's in the stratosphere (the atmospheric layer where ozone is most dense) break down easily due to cold weather and ice crystals in high clouds. The same processes are occurring in the Arctic.

Jaffe measures ozone with an instrument mounted on the roof of the Geophysical Institute. Readings taken this spring were significantly lower than ozone levels for the past 10 years. "You can call it a small hole--about a 10 percent depletion in ozone," Jaffe said. "It's the first time we've noticed it clearly."

Jaffe said the reduced amount of ozone this spring corresponds with much lower amounts measured over other northern regions such as Scandinavia and the former Soviet Union. And Jaffe expects the hole to get bigger, even though developed countries agreed to ban CFC's by 1996.

It takes a while for CFC's to be swept by the wind up to the stratosphere, causing a delayed effect between the release of CFC's and the destruction of ozone. The CFC's leaking from an old refrigerator in a landfill today may not destroy ozone molecules for several years.

"This is something that's going to get increasingly worse over the next 10 years, and then should start to improve as a result of the international bans on CFC's," Jaffe says.

Alaskans might not be the only ones affected by ozone depletion over the Arctic. Because ozone mixes freely throughout the stratosphere, ozone destroyed in the Arctic will be missed globally. That means people living on the equator may need more sunscreen because of reactions that happen above Alaska in the spring, the most chemically active time for CFC's to react with ozone.

Critics such as Limbaugh quote a few scientists who claim that either ozone depletion isn't a problem, or, if it is, humans aren't responsible. Common arguments are that CFC's, being heavier than air, don't make it up to the stratosphere, and natural sources of chlorine such as sea water and volcanoes add far more chlorine to the stratosphere than CFC's. Scientists counter those arguments by describing the atmosphere as a room with a fan, where winds mix light and heavy molecules until they are evenly scattered. Researchers also say much of the chlorine in sea water and from volcano emissions is removed by rain before it ever reaches the stratosphere.

"In any scientific endeavor, you'll always have a few mavericks," Jaffe says of the scientists Limbaugh quotes. "If you poll real scientists and ask them if there's an ozone problem, 95 percent will say yes."

It would be nice if Rush was right, as the bumper stickers say, but evidence such as that gathered by Jaffe shows that ozone depletion is occurring in the Arctic as well as the Antarctic.