Rise in emissions of ozone-destroying chemical despite ban puzzles scientists

  • IndiaToday.in
  • New Delhi
  • May 17, 2018
  • UPDATED 20:26 IST
Rise in emissions of ozone-destroying chemical desptite ban puzzles scientists
Ozone-destroying chemical emissions on rise despite ban | Picture for representation: Yuri Arcurs via Getty Images

A sharp and mysterious rise in emissions of a key ozone-destroying chemical has been detected by scientists, despite its production being banned around the world.

According to a new study, the emissions of the chemical can cause hole in the ozone layer. This chemical has been rising despite an international treaty that required an end to its production in 2010.

The scientists are not sure for now why emissions of this gas are going uphill.

This gas, Trichlorofluoromethane, or CFC-11, is a member of the family of chemicals most responsible for the giant hole in the ozone layer that forms over Antarctica each September.

The production of CFC-11 was widely due to its use as a foaming agent. The CFC-11 production was phased out by the Montreal Protocol in 2010.

Emissions from towers | Photo: Artem Hvozdkov via Getty Images

The new study that was published in the journal Nature and it documents an unexpected rise in the emissions of this gas, likely from new, unreported production.

"We're raising a flag to the global community to say, 'This is what's going on, and it is taking us away from timely recovery from ozone depletion.' Further work is needed to figure out exactly why emissions of CFC-11 are increasing and if something can be done about it soon.
- Lead author of the paper Stephen Montzka, a scientist at National Oceanic and Atmospheric Administration (NOAA) in the US

MEASUREMENT OF GLOBAL ATMOSPHERIC CONCENTRATIONS OF CFC-11

Scientists at NOAA and Cooperative Institute for Research in Environmental Sciences at University of Colorado, Boulder, in the US, for the study, made precise measurements of global atmospheric concentrations of CFC-11.

According to the results, the concentration of CFC-11 went downhill at an accelerating rate prior to 2002 as expected.

Soon then, the rate of decline remained almost stagnant till around 2012. It came as surprise when the scientists learnt that the rate of decline slowed by 50 per cent after 2012.

The skyline of downtown Los Angeles | Photo: REUTERS/Fred Prouser/Files

Montzka and fellow researchers when considered a number of possible causes, they were comfortable to conclude that CFC emissions must have gone up after 2012.

Conclusion was based on other changes which were recorded in NOAA's measurements during the same period. Other changes include widening of difference between CFC-11 concentrations in the northern and southern hemispheres -- evidence that the new source was somewhere north of the equator.

The towering Dhaulagiri Range of the Himalayas in central Nepal is a source of planet-girdling atmospheric waves that warm the stratosphere. Ozone holes over Antarctica, expected to last longer than last years record 11.6 million square miles (30 million square km) will likely spread more harmful ultra-violet radiation over the Southern Hemisphere. Ozone molecules, made up of three atoms of oxygen, form in a thin layer of the atmosphere around 76-18 miles above the earth and absorb ultraviolet radiation from the sun | Photo: REUTERS

When considering the measurements form Hawaii, it indicates the source of the increasing emissions are likely in eastern Asia.

According to Montzka, more research and work will be required to zero down on the locations of these emissions.

(With inputs from IANS)

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