Richard McLachlan, originally from New Zealand, waits for the Q train in Brooklyn. He delivers subway talks on the climate emergency, telling his fellow New Yorkers that they are "sleepwalking into a catastrophe."

A retiree gives unsolicited climate emergency talks on the New York City subway, frequently receiving applause. Now he wants to teach others how to preach their own messages to a crowd.

(Image credit: Ben James for NPR)