Can Pope Francis do what environmental movements like Earth Day and Greenpeace have failed to do—save the planet from human beings? Some pundits believe so. In early summer, Pope Francis is expected to release an historic document detailing the moral imperative to care for the Earth. Called an encyclical, the papal document is designed to convince the world’s 1.2 billion Catholics and others that climate change is a real and present danger that humanity can help to prevent.