Blue and Green: Pope Francis, the head of the Catholic church, made a religious case for acting against climate change in front of a large crowd that had gathered in Rome on Wednesday. In a short address, the pope talked about the biblical story of creation, as it is told in the book of Genesis, and of the beauty of nature and the grandeur of the cosmos. Then, he spoke of the risk of considering ourselves masters of creation. Creation is not a property, which we can rule over at will, or, even less, is the...