The restoration of the globe’s protective shield of ozone will be delayed by decades if fast-rising emissions of a chemical used in paint stripper are not curbed, new research has revealed.
Atmospheric levels of the chemical have doubled in the last decade and its use is not restricted by the Montreal protocol that successfully outlawed the CFCs mainly responsible for the ozone hole.
The ozone-destroying chemical is called dichloromethane and is also used as an industrial solvent, an aerosol spray propellant and a blowing agent for polyurethane foams.
Little is known about where it is leaking from or why emissions have risen so rapidly. The loss of ozone was discovered in the 1980s and is greatest over Antarctica.
But Ryan Hossaini, at Lancaster University in the UK and who led the new work, said: “It is important to remember that ozone depletion is a global phenomenon, and that while the peak depletion occurred over a decade ago, it is a persistent environmental problem and the track to recovery is expected to be a long and bumpy one.”
“Ozone shields us from harmful levels of UV radiation that would otherwise be detrimental to human, animal and plant health,” he said.
The chemical was not included in the 1987 Montreal protocol because it breaks down relatively quickly in the atmosphere, usually within six months, and had not therefore been expected to build up. In contrast, CFCs persist for decades or even centuries.
But the short lifespan of dichloromethane does mean that action to cut its emissions would have rapid benefits. “If policies were put in place to limit its production, then this gas could be flushed out of the atmosphere relatively quickly,” said Hossaini.
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