Last October, I watched as a passel of activists convened in front of WGBH, Boston’s public-television station. There were about three dozen of them on the concrete forecourt, many in matching T-shirts layered against the chill, but one middle-aged man wore a ministerial robe and clerical collar. Another activist of uncertain gender waved at passersby from the innards of an Elmo costume, which looked as though it had made one too many trips to the dry cleaners. WGBH employees, as well as cameramen and reporters on hand to cover the protest, weaved through the crowd.
The grassroots climate-change group…