David Gelles, reporter on the New York Times climate team and the Times’s Climate Forward newsletter and author of Dirtbag Billionaire: How Yvon Chouinard Built Patagonia, Made a Fortune, and Gave It All Away (Simon & Schuster, 2025), talks about New York City Climate Week and the challenge of several developing nations who are facing the challenges of a changing climate without the support of the United States, since the Trump administration withdrew the United States from the Paris Agreement.