Posted on Categories Air, Climate Change & Energy, WaterTags , , , ,

‘Ozone friendly’ chemicals are polluting the environment

Jordan Davidson, ECOWATCH

The Montreal Protocol of 1987 committed nations around the world to stop using the chlorofluorocarbons (CFC) that created a hole in the ozone layer. While it stands as one of the most effective environmental commitments the globe has seen, new research shows the side effects have been costly as chemicals dangerous to human health build up in the environment, as the BBC reported.

New research published in the journal Geographical Research Letters analyzed Arctic ice and found an unintended consequence of the Montreal Protocol. The compounds that replaced CFCs have been transported and transformed in the atmosphere, depositing far from their sources. The new generation of chemicals that replaced Freon, but are used in refrigerators, air conditioners and new cars have been accumulating since 1990.

“Our results suggest that global regulation and replacement of other environmentally harmful chemicals contributed to the increase of these compounds in the Arctic, illustrating that regulations can have important unanticipated consequences,” said Cora Young, a professor at York University in Canada, and an author of the paper, in a York University statement.

Scientists first discovered ozone depletion in the 1970s when they detailed the deterioration of the stratospheric ozone layer around the earth’s poles. As the hole over Antarctica opened and expanded, scientists found that the depletion of ozone was responsible for a greater intensity of ultraviolet radiation from the sun, causing an increase in the prevalence of skin cancer, eye cataract disease and other harmful effects on humans, as Courthouse News reported.

Scientists were soon able to pinpoint manufactured chemicals used in air conditioners and refrigerators, as well as solvents, propellants and chemical agents found in foam as the cause of the depleted ozone layer.

Now pollution from the chemicals that were created to replace the CFCs, known as short chain perfluoroalkyl carboxylic acids (scPFCAs), has proliferated around the world. The replacement chemicals are a class of PFAS, or forever chemicals, that have polluted waterways and made groundwater in certain areas toxic to drink.


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Banned ozone-harming gas creeps back, suggesting a mystery source

Henry Fountain, THE NEW YORK TIMES

Government scientists have detected an increase in emissions of an outlawed industrial gas that destroys ozone, potentially slowing progress in restoring the atmosphere’s protective ozone layer.

The scientists say that the increase is likely a result of new, unreported production of the gas, known as CFC-11, probably in East Asia. Global production of CFC-11, which has been used as a refrigerant and in insulating foams, has been banned since 2010 under an environmental pact, the Montreal Protocol.

The protocol was adopted in the late 1980s in response to studies that showed CFC-11 and similar gases, collectively known as chlorofluorocarbons, depleted atmospheric ozone. A layer of ozone in the stratosphere helps filter ultraviolet radiation from the sun that can cause skin cancer.


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Study shows that the ozone hole over Antarctica is beginning to heal, thanks in part to a global treaty

Amar Toor, THE VERGE
The ozone hole over the Antarctic has begun to heal, according to a new study, more than 30 years after its discovery. The findings suggest that global efforts to phase out ozone-depleting chemicals have been effective, though scientists still aren’t entirely sure about what’s driving the ozone hole’s recovery.
The study, published in the journal Science, combines data gathered from balloons and satellites to measure the area of the ozone layer over Antarctica from 2000 to 2015. Since 2000, the paper reports, the size of the ozone hole over Antarctica shrank by about 4 million square kilometers — an area equivalent to about half of the contiguous United States. Using computer simulations to account for changes in wind and temperature, the study’s authors estimate that about half of its reduction can be attributed to a decline in levels of the ozone-depleting gases chlorine and bromine.
The stratospheric ozone layer protects Earth from the sun’s harmful ultraviolet (UV-B) rays, which can cause skin cancer and cataracts in humans, and physiological damage in animals and plants.
Faced with growing evidence of ozone depletion, governments in 1987 ratified the Montreal Protocol, a global treaty that aimed to phase out the production of harmful chemicals known as chlorofluorocarbons (CFCs). At the time, CFCs were used in hairspray, aerosol cans, and refrigerators. A single CFC molecule can last for between 20 and 100 years in the atmosphere, and can destroy100,000 ozone molecules.
Previous studies have shown that the rate of ozone depletion has declined since the Montreal Protocol went into effect, and a 2014 United Nations report showed that Earth’s ozone layer has begun to heal. But the ozone hole over the Antarctic reached a record size in 2015, casting some doubt over claims of a recovery, and the UN report said it was still unclear whether healing in the Antarctic could be attributed to a decline in ozone-depleting gases.
Susan Solomon, professor of atmospheric chemistry and climate science at MIT and lead author of the study published this week, says her findings suggest that the Montreal Protocol has in fact worked.
“We are beginning to see clear signs that actions that society took to phase out chlorofluorocarbons are actually having the intended effect of beginning to heal the Antarctic ozone layer,” Solomon says, stressing that the recovery is still in its early phases. “It’s really a remarkable achievement for society,” she adds. “It’s a global environmental problem, and we have put ourselves on a good trajectory.”
Read more at: The world’s decision to fix the ozone hole is paying off 30 years later | The Verge