This Manhattan park gets a whole lot greener for New York’s 25th Annual Earth Day. You’ll learn all about sharing economies and eco-friendly living with exhibits of green vehicles and transportation, demonstrations from environmental campaigns and nonprofits,and some live performances too. Have some old clothes and a busted printer cluttering the apartment? Bring them! You can make a difference—and start spring cleaning—by recycling textiles and electronics at the event’s receptacles. While you’re at it, pack a gently used tome—cookbooks, mysteries, history, whatever you prefer—to trade for one you haven’t read at the book swap.