International Day for the Preservation of the Ozone Layer (Ozone Day)

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 19 Sep 2011

It’s over 25 years since British Antarctic Survey (BAS) scientists discovered the Ozone Hole above Antarctica. A paper published in the science journal Nature alerted the world to the dramatic and major environmental threat. The accumulation of chlorofluorocarbons (CFCs) used in refrigeration and air conditioning systems, and industrial solvents were found to deplete the protective layer of ozone that surrounds the Earth. Action by governments around the world led to the 1987 Montreal Protocol and its amendments, which ensured that production and consumption of CFCs, halons and carbon tetrachloride were phased out by 2000, and methyl chloroform by 2005.

But what is happening today – is the Ozone Hole showing signs of recovery? The World Meteorological Organization (WMO) reported in August that signs of ozone depletion were again appearing over the Antarctic. A few months earlier, the Antarctic ozone hole was making headlines: for the first time scientists found that it was “creating rainfall in subtropical regions”. In fact, closing of the hole in the world’s stratospheric ozone layer is still many decades away and the effects and interactions of ozone depletion on climate change are just starting to be understood. Continue reading

Ozone hole shows beginnings of recovery

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 03 December 2010

International efforts to phase out the use of chlorofluorocarbons and other ozone-depleting substances may be paying off, according to research revealed Friday by the National Institute of Water and Atmospheric Research in New Zealand.

Ozone hole 2010

The Antarctica ozone hole is the smallest it has been in the past five years, NIWA said.

While a one-year reduction in the ozone hole can’t indicate a recovery stage, NIWA’s atmospheric experts say the new information adds to a pattern of less severe ozone holes in recent years.

Satellite data combined with ground-base measurements, including the Antarctica New Zealand Arrival Heights observatory near Scott Base, show the hole reached a maximum area of about 22 million square kilometers (about 8.5 million square miles) and a 27 million ton deficit of ozone this year, compared with 24 million square kilometers (about 9.3 million square miles) and a 35 million ton deficit last year.

The largest hole, according to NIWA, was 29 million square kilometers (about 11.2 million square miles) and a 43 million ton deficit, recorded in 2000.

“We see a lot of year-to-year variation in ozone holes, caused by differences in atmospheric temperature and circulation,” said NIWA atmospheric scientist Stephen Wood in a prepared statement. “So we can’t definitively say the ozone hole is improving from one new year of observations.”

“However, we have now had a few years in succession with less severe holes,” Wood said. “That is an indication we may be beginning to see a recovery.” Continue reading