Bill McKibben thought he knew where he came from. He grew up in the tidy, affluent and predominantly white suburban community of Lexington, Massachusetts. As a teenager, he gave tours on the Lexington Battle Green, regaling visitors with tales about the opening shots of the American Revolution. He thought the United States was the greatest force for good in the world.

Fifty years later, McKibben, now 61, has a very different perspective. He sees a world riven by racial and economic inequality. He has dedicated his life to stopping the climate crisis, a human-caused disaster that his generation has done much to create. The big question on McKibben’s mind today is this: 

What the hell happened?

Bill McKibben tackles this question in his new book, “The Flag, The Cross, and the Station Wagon: A Graying American Looks Back at His Suburban Boyhood and Wonders What the Hell Happened.” McKibben lives in Ripton, Vermont, and is the author of more than a dozen other books, including “The End of Nature,” which was the first book to warn the general public about the climate crisis. He is a regular contributor to the New Yorker, writes a blog about the climate crisis called The Crucial Years and founded the global grassroots climate campaign 350.org. He was the recipient of the Gandhi Peace Award and the Right Livelihood Award, known as “the alternative Nobel.” He is the Schumann Distinguished Scholar in Environmental Studies at Middlebury College. His latest project is Third Act, which is organizing people over 60 for progressive change.