Washington – This year’s Antarctic ozone hole is the biggest ever, government scientists said Thursday.
The so-called hole is a region where there is severe depletion of the layer of ozone – a form of oxygen – in the upper atmosphere that protects life on Earth by blocking the sun’s ultraviolet rays.
Scientists say human-produced gases such as bromine and chlorine damage the layer, causing the hole.
That’s why many compounds such as spray-can propellants have been banned in recent years.
“From Sept. 21 to 30, the average area of the ozone hole was the largest ever observed, at 10.6 million square miles,” said Paul Newman, atmospheric scientist at NASA’s Goddard Space Flight Center, Greenbelt, Md.
That’s larger than the area of North America.
The size and thickness of the ozone hole vary from year to year, becoming larger when temperatures are lower.
Because of international agreements banning ozone-depleting substances, researchers calculated that these chemicals peaked in Antarctica in 2001 and have been declining.
However, many of them have extremely long lifetimes once released into the air.
While there are year-to-year variations, scientists expect a slow recovery of the ozone layer by 2065, anticipating declines in the use of damaging chemicals.
