I haven’t been involved in a super-abundance of protest marches through the years, though I did carry a sign calling for the end of the war in Vietnam in the early 1970s, and, last summer, I took my wife and daughter downtown with me for a demonstration against the Keystone XL pipeline. In any case, I’m considering joining this one: Bill McKibben, who leads the environmentalist group 350.org, has invited you and me to “A Call to Arms: An Invitation to Demand Action on Climate Change” to be held in New York City next September 20/21. I can’t think of a place I’d rather be.