Thanks to the global phaseout of ozone-depleting chemicals laid out in the Montreal Protocol, the planet’s ozone layer is on track to recover within four decades. Success in phasing out ozone-eating chemicals is offering hope that the world can transition away from fossil fuels, reduce greenhouse gases and limit global warming. This is an important example of how multilateralism works to address environmental issues that cross borders. Follow @unepozone for regular related #ClimateAction updates.