The United Nation backed report this week found that the hole in the ozone layer has continued to repair. The news is being hailed as a demonstration of what global agreements can achieve, and an inspiration for more ambitious climate action to halt the rise in world temperatures.The study, called “Scientific Assessment of Ozone Depletion: 2018”, is released every four years, and monitors the recovery of ozone in the stratosphere. Ozone is the layer that protects us from harmful layers of ultraviolet rays from the sun.In Montreal on Sept. 16, 1987, the international treaty - Montreal Protocol, (Montreal Protocol on Substances That Deplete the Ozone Layer) was signed. It aimed to regulate the production and use of chemicals that contribute to the depletion of Earth's ozone layer. (Think aerosols and refrigerants.) The size of the hole has been monitored ever since.Recovery from the holes and thinning caused by aerosol chemicals has progressed at a rate of about 1% to 3% a decade since 2000, meaning the ozone layer over the northern hemisphere should heal by the 2030s, if current rates are sustained.The UN expects the Northern (Arctic) hole to be closed by around 2030 and the southern (Antarctic) to be closed by 2060.
(This image shows areas of low ozone above Antarctica on September 2000, left, and September 2018. Photograph: Nasa/AP) The scientists on the UN panel said the development demonstrates that when the world comes together, it can counteract a brewing ecological crisis. "It's a victory for diplomacy and for science and for the fact that we were able to work together," said chemist Mario Molina. In 1974, Molina and F. Sherwood Rowland wrote a scientific study forecasting the ozone depletion problem. They won the 1995 Nobel Prize in chemistry for their work.“The Montreal Protocol is one of the most successful multilateral agreements in history for a reason,” said Erik Solheim, head of UN Environment. “The careful mix of authoritative science and collaborative action that has defined the Protocol for more than 30 years and was set to heal our ozone layer is precisely why the Kigali Amendment holds such promise for climate action in future.”