Following the recent swelling of the Antarctic ozone hole to near-record size, the two countries exposed to the hole’s heightened ultraviolet radiation every year are stepping up efforts to comprehend the phenomenon’s environmental and health effects.
Argentina and Chile in March are scheduled to hold a meeting in Buenos Aires to inventory current ozone-hole monitoring and research in the Southern Cone. Afterwards, they plan to form a bilateral commission that will coordinate joint ozone-hole study and seek international funds to assess the hole’s effects on southern Argentine and Chilean communities and ecosystems.
Since it was first detected in the early 1980s, the Antarctic ozone hole typically has appeared in the southern-hemisphere spring. It regularly reaches the southern tip of Chile and Argentina, an area that includes the 120,000-resident city of Punta Arenas, Chile, and Ushuaia, an Argentine community of 30,000.
Last year, the hole reached record sizes for August and September and extended over southern Chile and Argentina on six occasions. Its maximum size—on Sept. 11—was 10.9 million square miles (28.2 million sq. km). That’s equivalent to the area of North America, and just short of the historic ozone-hole record, which was set in 2000.
According to the World Meteorological Organization (WMO), a UN agency that coordinates scientific activity on climate issues, this year’s hole not only stood in stark contrast to last year’s unusually small hole, but it peaked twice, nearly attaining its maximum size again in late September. That bucks the hole’s usual tendency to start shrinking in mid-September.
Deepest ozone hole on record
Michael Proffitt, the WMO’s leading ozone-hole expert, says the thinnest part of the hole, which contains less than half the normal levels of atmospheric ozone, accounted for nearly two-thirds of the entire hole. That made last year’s hole by far the deepest on record.
Says Proffitt: “The ozone hole is getting larger, deeper and is lasting longer. It has never stayed this large, this late.”
In the Antarctic, the ozone layer naturally diminishes as early as mid-August and stays thin sometimes until late December. Cold temperatures combined with the return of sunlight in the spring hasten ozone loss. The same process occurs over the Arctic. But ozone thinning over Antarctica is more dramatic due to the region’s colder temperatures and longer-lasting polar stratospheric clouds, a key factor in ozone loss.
It became still more extreme in recent decades thanks to the accumulation in the atmosphere of manmade ozone-depleting chemicals, which have thinned the ozone layer worldwide. With ozone-depleting chlorofluorocarbons (CFCs) subject to tightening controls in recent years, many scientists predict the ozone layer will begin to recover this decade and be fully restored by 2050.
But Claudio Casiccia, director of the ozone laboratory at Magallanes University in Punta Arenas, says no such trend is evident yet.
“Last year, it [the ozone hole] was much smaller, but that was a complete anomaly,” Casiccia says. “The large size this year was totally opposite. We need to wait a few more years before we can safely predict when a recovery is on its way.”
Lagos and Kirchner speak out
In August, Chile’s President Ricardo Lagos and Argentina’s President Nestor Kirchner met aboard a boat in Lake Argentino, next to Argentina’s Perito Moreno Glacier.
The result was the “Calafate Declaration,” an agreement under which the two countries pledged to intensify bilateral scientific study of local ozone-hole effects and to seek international support for the effort. They also expressed concern over the effects of global warming, urging rich nations to redouble efforts to reduce greenhouse gas emissions.
Officials in the two countries say rich nations bear the bulk of the responsibility for the ozone-hole and global warming problems. In a speech to the Argentine Congress, Lagos said Argentina and Chile must “raise our voices to denounce this situation.”
It is as a follow-on step to the Calafate Declaration that the foreign ministries of Chile and Argentina are holding March’s joint ozone meeting and forming the bilateral commission. The meeting is expected to include invitees from government agencies, scientific institutions and non-governmental organizations.
Gaston Torres, director of the ozone-monitoring program for Chile’s Meteorological Service, says that so far, very little ozone-hole research is being done in either country. But in the wake of the Calafate Declaration, Chile’s Casiccia and two Argentine scientists from the University of Buenos Aires—Pablo Canziani and Eduardo Luccini—have launched a research initiative to monitor ultraviolet-radiation levels throughout Chile and Argentina.
Many other such projects are on the way, Canziani says. He adds: “By combining efforts we hope to share scarce resources and improve our chances of getting international support for ozone research in the Southern Cone.”
- James Langman