It was an act of faith. Pope Francis challenged a global audience to protect the planet from climate change in his highly anticipated encyclical, released last week. “The Earth, our home, is beginning to look more and more like an immense pile of filth,” he said in a radical message, delivered in the no-nonsense style that has endeared him to 9 out of 10 Catholics. I recognize the positive impact Francis has had and agree that “human beings, while capable of the worst, are also capable of rising above themselves” to make a fresh start. Ahead of his U.S. visit this September, I hope fellow Americans will heed his call for change. I know I will.