CFC ban bought us time to fight climate change, say scientists
A worldwide ban on ozone-depleting chemicals in 1987 has averted a climate catastrophe today, scientists say. The Montreal Protocol on Substances that Deplete the Ozone Layer , banning chemicals such as chlorofluorocarbons, has now simulated our "world avoided". Without the treaty, Earth and its flora would have been exposed to far more of the Sun's ultraviolet (UV) radiation. Former UN Secretary General Kofi Annan has called it "perhaps the single most successful international agreement". Continued and increased use of chlorofluorocarbons (CFCs) would have contributed to global air temperatures rising by an additional 2.5C by the end of this century, the international team of scientists found. Part of that would have been caused directly by CFCs, which are also potent greenhouse gases. But the damage they cause the ozone layer would also have released additional planet-heating carbon dioxide - currently locked up in vegetation - into the atmosphere. "In past experiments, people have exposed plants - basically tortured plants - with high levels of UV," lead researcher Dr Paul Young, of the Lancaster Environment Centre, said. "They get very stunted - so they don't grow as much and can't absorb as much carbon." The scientists estimated there would be: "What we see in our 'world-avoided experiment' is an additional 2.5C warming above any warming that we would get from greenhouse-gas increases," Dr Young said. But similar collective action to limit greenhouse-gas emissions was likely to be much more challenging. "The science was listened to and acted upon - we have not seen that to the same degree with climate change," he told BBC Radio 4's Inside Science programme . The experiment could appear to suggest hope for an "alternative future" that had avoided the worst consequences of climate change. "But I would be cautious of using it as a positive example for the climate negotiations," Dr Young said. "It's not [directly] comparable - but it's nice to have something positive to hold on to and to see that the world can come together." Follow Victoria on Twitter Ozone layer 'rescued' from CFC damage Morocco rescuers dig with bare hands as foreign aid sent US denies Cold War with China in historic Vietnam visit How Russia and West agreed on Ukraine G20 language How Russia and West agreed on Ukraine G20 language US denies Cold War with China in historic Vietnam visit 'Everyone in this village is either dead or missing' A Serbian scientist's long quest to name Srebrenica's dead How chronic pain feels for me. Video How chronic pain feels for me Guyana scrambles to make the most of oil wealth The spongy creatures cleaning Zanzibar's oceans. Video The spongy creatures cleaning Zanzibar's oceans Inside a 'hijacked' South African building. Video Inside a 'hijacked' South African building The rise and fall of a parenting influencer Florida's first hurricane-proof town The greatest spy novel ever written? Why is everyone crazy about Aperol? 2023 BBC.