In celebration of Earth Day, Yoko Ono declares “I LOVE YOU EARTH” across billboards in London, Liverpool, Glasgow, and other cities in the UK. The message, set in stark black and white, is a call for climate action and a nod to Ono’s eponymous 1985 song and text piece, which includes the lyrics: “I love you, earth (…) I know I never said it to you / But I wanna say it now.” The two-week action is part of Serpentine Galleries’ multi-year project “Back to Earth,” which has 60+ artists respond to the environmental crisis.