Dichloromethane and the Ozone Layer
How dichloromethane is stymieing efforts to restore the ozone layer
Back in 1985, we first knew about the hole in our ozone layer which protects us from the sun’s UV rays. With a hole in the ozone layer, this enables the sun’s ultra violet light to penetrate our atmosphere. CFCs were blamed for the ozone layer’s hole so, come the late 1980s, they were banned from spray-on deodorants and refrigerators. This year, a recent study by Lancaster University, it was found that dichloromethane was having a similar effect to the ozone layer’s hole.
Whereas CFCs (Chlorofluorocarbons) were banned, as per the Montreal protocol in 1987, dichloromethane (as used in paint stripping chemicals) slipped through the net. As CFCs are slow to break down, DCMs break down quickly. Hence its exclusion from the Montreal protocol. Between 2004 and 2014, DCM levels rose by 8% year on year.
Should dichloromethane chemicals rise at a similar level, recovery of the ozone layer will be delayed by 30 years, till about 2090. Any action to cut DCM emissions would have immediate benefits and speed up the ozone layer’s recovery time. Ryan Hossaini from Lancaster University said: “If policies were put in place to limit its production, then this gas could be flushed out of the atmosphere relatively quickly.”
From the University of Manchester, its atmospheric physicist Grant Allen said: “Whatever the source of this gas, we must act now to stop its release to the atmosphere in order to prevent undoing over 30 years of exemplary science and policy work which has undoubtedly saved many lives.”
Last year, the hole in the ozone layer was reported to be healing. Could changes to dichloromethane usage help to fill the gap in quicker time?
Premium Doors and Furniture, 30 June 2017.