Guardian: Two hundred children, a horde of farm animals and a bishop being followed by camera crews and journalists in an ark down the Thames might sound like a media circus. That, of course, is the point. In a loose recreation of the Noah story our ark will be a buzz with enthusiastic, young climate change activists fresh from delivering their own, homemade, ark to the prime minister. Accompanied by the music of a brass quintet, the temporary residents of the ark will join together in song as we sail …