New method to assess ozone layer recovery

Researchers have developed a new method for assessing the impacts of ozone-destroying substances that threaten the recovery of the ozone layer. The Montreal Protocol is successfully protecting the ozone layer, but there is increasing evidence to suggest the ozone hole is recovering slower than expected John Pyle Published in the journal Nature , their method - the Integrated Ozone Depletion (IOD) metric - provides a useful tool for policymakers and scientists. The IOD has been designed to provide a straightforward way to measure the effects of unregulated emissions of substances that deplete the ozone layer, and evaluate how effective ozone layer protection measures are. The ozone layer is found in a region of the earth's atmosphere known as the stratosphere, and acts as an important protection barrier against most of the sun-s harmful ultraviolet rays. Ozone-depleting gases such as chlorofluorocarbons, better known as CFCs, have been phased out under the Montreal Protocol - an international treaty agreed to protect the ozone layer. The Montreal Protocol has been largely successful, but illegal breaches are jeopardising its efficacy. The IOD indicates the impact of any new emissions on the ozone layer by considering three things: the strength of the emission, how long it will remain in the atmosphere, and how much ozone is chemically destroyed by it.