Over the last decade around New York, a host of more localized concerns and groups have mobilized around a new bevvy of “green” causes: banding together to rebuild after Sandy, campaigning for locally grown and organic food, and fighting against fracking. At the People’s Climate March, they found welcome and common cause with those pushing for divestiture from fossil fuels, as well as those from more far flung locales, those rebuilding on the Gulf Coast after Katrina, those from island nations and from other communities on the “front line” of environmental change. In an earlier...