In his long-awaited encyclical on the environment and climate change, Pope Francis has called for swift action to save the planet from environmental ruin, urging world leaders to hear “the cry of the Earth and the cry of the poor.” He called for a change of lifestyle in rich countries steeped in a “throwaway” consumer culture, and an end to “obstructionist attitudes” that sometimes put profit before the common good. Pope Francis said protecting the planet is a moral and ethical “imperative” for believers and nonbelievers alike that should supersede political and economic interests. A major theme of the encyclical is the disparity between rich and poor. “We fail to see that some are mired in desperate and degrading poverty, with no way out, while others have not the faintest idea of what to do with their possessions, vainly showing off their supposed superiority and leaving behind them so much waste which, if it were the case everywhere, would destroy the planet,” he said. We speak to Naomi Klein, author of “This Changes Everything: Capitalism vs. the Climate.” She has been invited to speak at the Vatican, where she will speak at the “People and Planet First: The Imperative to Change Course” conference. And here in New York is Nathan Schneider, columnist at America magazine, a national Catholic weekly magazine published by the Jesuits.