Paul McCartney has made a music video in support of his family’s Meat Free Mondays campaign, which urges people to take a weekly break from eating meat in an effort to help the environment. The song – which dates back to 2009, when the outspoken vegetarian cofounded the effort with his daughters Mary and Stella – lays out all the benefits to slightly changing one’s diet, including reducing greenhouse gases and slowing down the polar ice thaw and rising ocean levels. His video features people from all over the world holding up signs with the song’s lyrics, including celebrities like Woody Harrelson, Twiggy and actress Joanna Lumley. McCartney makes a wide-smiled appearance at the end.