Science: The leader of the world's largest Christian faith might succeed in doing something that many experts have failed to achieve: communicating the urgency of global warming. Thats one reaction Pope Franciss encyclical on climate change and the environment, Laudato Si ("Praised Be"), released today. It includes a call for "a new dialogue" on the planet's future, an accessible summary of climate science, a stinging critique of international talks that have produced ineffectual environmental agreements,...