Antarctic ozone shows signs of healing

Source: Eathsky.org

Every year for the past few decades – during Southern Hemisphere spring, around September and October – chemical reactions involving chlorine originating from chlorofluorocarbons (CFCs) have been observed to cause ozone above Earth’s south polar region to be destroyed. This week (June 30, 2016), scientists led by Susan Solomon at MIT said they’ve now observed “the first fingerprints of healing” in the Antarctic ozone layer. Their work is published in the journal Science.

The team found that the September ozone hole has shrunk by more than 1.5 million square miles (4 million square km, about half the area of the contiguous U.S.) since 2000, when September ozone depletion was at its peak.

They also showed, for the first time, that this recovery has slowed somewhat at times due to the effects of volcanic eruptions from year to year.

Overall, however, they said, the ozone hole appears to be on a healing path. In a statement from MIT, they said they see no reason why:… barring future volcanic eruptions, the ozone hole shouldn’t shrink and eventually close permanently by mid-century.

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Read more: http://earthsky.org/earth/antarctic-ozone-shows-signs-of-healing