On June 1, President Donald Trump declared that he was withdrawing the United States from the Paris climate accord, an international agreement meant to significantly reduce greenhouse gas emissions and limit the global average temperature increase to no more than 2 degrees Celsius. For those who accept the reality of the threat posed by climate change, the news has sparked a good deal of anger, outrage, and not a small amount of despair for the fate of our planet.    Despair not, says our guest, Carl Pope, the former Executive Director of the Sierra Club, and the co-author of the optimistic new book Climate of Hope: How Cities, Businesses and Citizens Can Save the Planet, co-written with former New York City Mayor Michael Bloomberg.    In a timely conversation with Point of Inquiry’s new host Paul Fidalgo (in his first episode as host!), Pope rejects doomsday attitudes about global warming, insisting that the window to stop climate change has not closed. He’ll tell us why he’s so optimistic, and what he thinks about the president’s decision to reject the Paris accord.