Context: China has been illegally emitting Trichlorofluoromethane or CFC-11 — the banned ozone-depleting chemical — according to the research published in the journal Nature recently.

Key findings:

• CFC-11 was phased out under the 1987 Montreal Protocol. Despite being the signatory to the Montreal Protocol, and agreeing to phase out production of CFC-11 in 2010, China continued to emit the polluting gas.
• Emissions of CFC-11 were on the rise since 2013. In fact, the emissions increased by 25 per cent since 2012. Between 2008 and 2012, eastern China emitted an average of about 6,400 metric tonnes of CFC-11 per year. That number increased to about 13,400 metric tonnes per year from 2014 to 2017.

Reasons behind:

• China has the world’s largest polyurethane foam market, accounting for about 40 per cent of the world’s consumption.
• Chinese foam manufacturers have been using CFC-11 illegally to save on the higher cost of alternatives, such as hydrochloro-fluorocarbons like HCFC-141b, which is to be phased out in China by 2026.

Why limit the use of CFC- 11?

• The hole in the ozone is on the path to recovery according to the World Meteorological Organization’s (WMO’s) assessment; and reduction in the atmospheric concentration of CFC-11 has made the second-largest contribution to the decline in the total atmospheric concentration of ozone-depleting chlorine since the 1990s. But this gas still contributes one-quarter of all chlorine reaching the stratosphere, and a timely recovery of the stratospheric ozone layer depends on a sustained decline in CFC-11 concentrations.
• Continued success of the Montreal Protocol in protecting stratospheric ozone depends on continued compliance and China must adhere to it.

What you need to know about the Ozone layer?

The ozone layer absorbs most of the Sun’s ultraviolet light which is harmful to human life and other life forms. The layer absorbs about 97 to 99% of ultraviolet rays and maintain the ozone-oxygen cycle. Dobson unit is a unit which is used to measure the ozone in the atmosphere at a standard temperature and pressure.

Montreal protocol:

• The Montreal Protocol on Substances that Deplete the Ozone Layer was designed to reduce the production and consumption of ozone depleting substances in order to reduce their abundance in the atmosphere, and thereby protect the earth’s fragile ozone Layer. The original Montreal Protocol was agreed on 16 September 1987 and entered into force on 1 January 1989.
• The Montreal Protocol includes a unique adjustment provision that enables the Parties to the Protocol to respond quickly to new scientific information and agree to accelerate the reductions required on chemicals already covered by the Protocol. These adjustments are then automatically applicable to all countries that ratified the Protocol.
• Montreal Protocol stipulates that the production and consumption of compounds that deplete ozone in the stratosphere-chlorofluorocarbons (CFCs), halons, carbon tetrachloride, and methyl chloroform-are to be phased out by 2000 (2005 for methyl chloroform). These compounds significantly deplete the stratospheric ozone layer that shields the planet from damaging UV-B radiation.

Outcomes:

The phaseout of controlled uses of ozone depleting substances and the related reductions have not only helped protect the ozone layer for this and future generations, but have also contributed significantly to global efforts to address climate change; furthermore, it has protected human health and ecosystems by limiting the harmful ultraviolet radiation from reaching the earth.