May 14, 2011 09:36 GMT  ·  By
The ozone layer hole above Antarctica may already be closing, a new study suggests
   The ozone layer hole above Antarctica may already be closing, a new study suggests

Much to their surprise, climate scientists keeping an eye on the hole that developed in the ozone layer above Antarctica noticed that the gap is beginning to close. This is remarkable because the process is taking place a decade earlier than scientists first calculated any effect would be visible.

Studies conducted 20 to 30 years ago indicated chlorofluorocarbons (CFC) as the main class of compounds that was affecting this layer of the atmosphere, causing ozone molecules to break apart.

Without them, more ultraviolet (UV) radiation from the Sun made their way to the Earth's surface, causing an increased risk of people developing skin cancer and DNA mutations. Experts then knew that something needed to be done to mitigate the situation.

After years of publishing studies, the international community took action with the signing of the 1986 Montreal Protocol on Substances That Deplete the Ozone Layer. This prevented signing nations from releasing additional amounts of CFC into the atmosphere.

When this happened, experts estimated that the positive results would become apparent starting around 2023. But this turned out not to be the case. The effects of the Montreal Protocol started showing up as soon as the late 1990s.

At this point, there is a clear “healing” trend visible in the ozone layer above Antarctica, say researchers in Australia. “The key is to account for large year-to-year fluctuations that have obscured a gradual increase in the long-term evolution of ozone,” says expert Murry Salby.

The investigator holds an appointment as an atmospheric scientist at the Macquarie University, in Sydney. Details of the study he and his team conducted appear in the May 6 online issue of the esteemed scientific journal Geophysical Research Letters.

Despite the optimistic tone of the new research, not all experts are convinced that its conclusions are entirely accurate. Critics don't doubt that improvements are taking place, what they are in doubt about is the time frame the study puts forth, Science News reports.

“I expect Antarctic ozone to be slowly recovering, but would have thought that we need several more years of data to statistically show this,” says Johns Hopkins University (JHU) atmospheric scientist Darryn Waugh.

“My response [to the research] is slightly cautious. It’s a bold claim,” adds Paul Young, who is an atmospheric chemist at the Boulder, Colorado-based Earth System Research Laboratory.

The ESRL is managed and operated by the US National Oceanic and Atmospheric Administration (NOAA).