Neil Young — the planet-loving rock ‘n’ roll hall-of-famer — made a memorable guest appearance on the Colbert Report Tuesday. Young sauntered on stage in an EARTH tee to talk about impeaching Obama for fracking. But the best part of the episode was when Stephen Colbert joined in to perform a duet of Young’s new single, “Who’s Gonna Stand Up (And Save the Earth)” — only to answer casually back, “not me.” Watch the duet above and check out Young’s interview with Colbert here.