High above our heads the ozone layer of the stratosphere absorbs enough of the sun’s deadly ultraviolet radiation to make possible life on Earth. But just a few decades ago an alarming depletion of the ozone layer generated worldwide concern over resulting increases in skin cancer, cataracts, and other health issues. These concerns led to the adoption of the Montreal Protocol in 1987, celebrated today, which bans the production of chemicals that cause ozone depletion. In his 2015 encyclical Laudato si’, Pope Francis applauds the Protocol for helping to protect the Earth, our common home. What can you do for our Earth today?