After decades of thinning, Earth's ozone layer is slowing recovering, the United Nations (UN) said in a report released Monday, highlighting how international cooperation can help tackle major environmental issues.
The ozone layer, which protects humans and other species from the sun's highly hazardous ultraviolet radiation, has been declining since the 1970s due to the effect of chemicals such as chlorofluorocarbons (CFCs) and similar gases found in refrigerants and aerosol spray cans.
But the new study — Scientific Assessment of Ozone Depletion: 2018 — shows that ozone in parts of the stratosphere has recovered at a rate of 1-3 percent since 2000 due to the success of the 1987 Montreal Protocol, the landmark multilateral environmental agreement that phased out ozone-depleting substances.
“It's really good news,” report co-chairman Paul Newman, chief Earth scientist at NASA's Goddard Space Flight Center, told the Associated Press. “If ozone-depleting substances had continued to increase, we would have seen huge effects. We stopped that.”
That said, the ozone layer still has a long road to complete recovery. If progress continues, the Northern Hemisphere and mid-latitude ozone should be healed by the 2030s, followed by the Southern Hemisphere in the 2050s and polar regions by 2060, according to the study.
“I don't think we can do a victory lap until 2060,” Newman added to the AP. “That will be for our grandchildren to do.”
Notably, scientists have recently detected a mysterious rise of CFCs out of eastern Asia.
Newman also pointed out to the AP that the refrigerants that are currently being used also need to be replaced themselves with chemicals that do not worsen global warming.
Next year, the Montreal Protocol is set to be strengthened with the ratification of the Kigali Amendment, which slashes climate-warming gases in refrigerators, air conditioners and related products.
Still, the new report is “an inspiration for more ambitious climate action to halt a catastrophic rise in world temperatures,” the UN said in a press release of the new report, adding the findings “provide a ray of hope” less than a month after the Intergovernmental Panel on Climate Change released its dire report urging drastic action to stave off catastrophic climate change.
The writers of the new report said that with the full implementation of the Kigali Amendment, the world can avoid up to 0.4 percent of global warming this century, meaning that it will play a major role in keeping the global temperature rise below 2°C.
“The Montreal Protocol is one of the most successful multilateral agreements in history for a reason,” Erik Solheim, head of UN Environment stated in the press release. “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.”
Main image: A view of Earth's atmosphere from space. Credit: NASA, public domain