Above the South Pole, the small (by atmospheric standards), man-made ozone "hole" is getting slightly smaller, Bloomberg reported.
At face value, the news is good for the planet. The hole, which is really just an area of extremely low ozone concentrations, permits a greater concentration of harmful rays to penetrate the atmosphere, causing skin cancer and damage to plants and plankton, according to Earthweek.
Scientists, however, aren't ready to call it a sign of healing.
"We cannot say that this represents recovery, but it is certainly good news to see this year on the higher side of the average ozone range," Brian Johnson, of the National Oceanographic and Atmospheric Administration (NOAA), told Earthweek.
But they do believe it is a sign in the positive direction and that the gap will gradually fade in the next few decades, according to Earthweek.
The formation of the hole was caused by manmade, ozone-depleting chlorofluorocarbons, according to Earthweek. It opens during Arctic spring, reaches its peak in December (to roughly the size of Canada and the U.S.), and then closes until next spring.
As the world has more strictly monitored the release of harmful emissions, the size has slowly decreased. This year's average coverage of 7.3 million miles is down from 8 million miles last year and a record 10 million miles in 2006, Earthweek reported. The largest single day in 2013 was about a month and a half ago when the gap reached 9.3 million miles (size of North America), according to Red Orbit.
"Levels of most ozone-depleting chemicals in the atmosphere have gradually declined as the result of the 1987 Montreal Protocol, an international treaty to protect the ozone layer by phasing out production of ozone-depleting chemicals," NASA told Red Orbit. "As a result, the size of the hole has stabilized, with variation from year to year driven by changing meteorological conditions."
NASA attributes much of this year's decline to higher global temperatures -- another reason why scientists who monitor the ozone are careful to call this year a huge improvement, according to Bloomberg.
"There was a lot of Antarctic ozone depletion in 2013, but because of above average temperatures in the Antarctic lower stratosphere, the ozone hole was a bit below average compared to ozone holes observed since 1990," said Paul Newman, an atmospheric scientist and ozone expert at NASA's Goddard Space Flight Center in Maryland.
The first nine months of 2013 are the 28th hottest on record, Bloomberg reported.