The ozone layer in our upper atmosphere protects Earth from the harmful effects of ultraviolet radiation. The use of human-produced chemicals in our atmosphere used for many years depleted Earth’s ozone layer. However, the reduction in the consumption of ozone-depleting substances driven by the Montreal Protocol – an international treaty designed to protect the ozone layer – has allowed for the ozone hole to slowly recover. This global agreement demonstrates the power of international commitment and immediate global action in protecting our environment.

ESA has been involved in monitoring the ozone for over two decades. Today, 16 September, marks