How did we save the ozone layer?

A UN report has found the Earth’s ozone layer is on course to be healed within the next 40 years. What was once humanity’s most feared environmental peril is now an example of how the world can take collective action. Madeleine Finlay speaks to atmospheric scientist Paul Newman about this momentous achievement and whether it really is the end of the story. Help support our independent journalism at theguardian.com/sciencepod