Likely ‘cheating’ on ozone treaty: experts
‘Arctic oil undrillable
PARIS, May 16, (AFP): The decline in the atmosphere of an ozone-depleting chemical banned by the Montreal Protocol has recently slowed by half, suggesting a serious violation of the 196-nation treaty, researchers revealed Wednesday.
Measurements at remote sites — including the government-run Mauna Loa Observatory in Hawaii — of the chemical, known as CFC-11, point to East Asia as the source or renewed production.
“We show that the rate of decline of atmospheric CFC-11 was constant from 2002 to 2012, and then slowed by about 50 percent after 2012,” an international team of scientists concluded in a study.
“This evidence strongly suggests increased CFC-11 emissions from eastern Asia after 2012.”
The ozone layer in the stratosphere, 10-to-40 kilometres (6-25 miles) above Earth’s surface, protects life on the planet from deadly ultraviolet radiation.
The 1987 Montreal Protocol banned industrial aerosols such as chlorofluorocarbons (CFCs) that were chemically dissolving ozone, especially above Antarctica.
At its most depleted, around the turn of the 21st century, the ozone layer had declined by about five percent.
Today, the “hole in the ozone” over the South Pole is showing clear signs of recovery.
The findings, reported in Nature, also have implications for the fight against climate change.
“Perhaps even more serious is the role of CFCs as long-lived greenhouse gases,” noted Joanna Haigh, a professor at Imperial College London, in commenting on the study.
Two decades ago, CFCs — more potent by far as greenhouse gases than carbon dioxide or methane — accounted for around ten percent of human-induced global warming.
Widely used in 1970s and 1980s as propellant in aerosol sprays, as well as in refrigeration and air conditioning systems, CFCs do not exist in nature.
“This is the first time that emissions of one of the three most abundant, long-lived CFCs have increased for a sustained period since production controls took effect in the 1980s,” the study concluded.
CFC-11 still contributes about a quarter of all chlorine — the chemical that triggers the breakdown of ozone — reaching the stratosphere.The researchers said that the less rapid decline of CFC-11 could prevent ozone from returning to normal levels, or at least as quickly as hoped.
An architect of the Paris climate agreement urged governments on Tuesday to halt oil exploration in the Arctic, saying drilling was not economical and warming threatened the environmentally fragile region.
Christiana Figueres, formerly head of the UN Climate Change Secretariat when the Paris accord was reached by almost 200 nations in 2015, told Reuters by telephone “the Arctic has been rendered undrillable.”
The past three years have been the hottest since records began in the 19th century, and Figueres said the heat was a threat to everything from Australia’s Great Barrier Reef to ice in Antarctica.
The former Costa Rican diplomat who campaigns for a peak in global emissions by 2020 said it made no economic sense to explore in the Arctic, partly because it was likely to take years to develop any finds.