Earth Day hits 40 this year, so be sure to buy it an organic cotton “Lordy, Lordy, Look Who’s 40!” sweatshirt or something. (Just kidding—Earth Day would totally hate that gift.) Organizations citywide are celebrating all week by hosting cleanups, green living info workshops, and other activities. A partial list of Earth Day events selected from our in-box follows; many other events are listed at earthday.net/chicago. —Lauri Apple
Earth Day Service Project REI and the nonprofit Friends of the Parks cohost this cleanup project that involves tree mulching, trail maintenance, seeding, weeding, and planting. Register with REI. 
Sat 4/17, 9 AM-noon, Gompers Park, 4222 W. Foster, 312-951-6020, rei.com/lincolnpark. 
Eco-Expo Family-friendly activities, educational workshops on green living, a fashion show featuring clothes made from recycled materials, and organic food and beverages. Sat-Sun 4/17-4/18, 10 AM-5 PM, Lincoln Park Zoo, 2200 N. Cannon, 312-742-2000, lpzoo.org.
Green Family Festival The Green Parents Network hosts this festival featuring experts, demonstrations, panel discussions, and exhibitors, all focused on holistic parenting. Participants include WGN’s Mr. Fix-It Lou Manfredini and the nonprofit Working Bikes Cooperative, which will host a bike swap and collect donated bikes to distribute to needy people worldwide. Sat 4/17, 10 AM-6 PM, Sun 4/18, 10 AM-5 PM, Irish American Heritage Center, 4626 N. Knox, 773-282-7035, irish-american.org, $5 per family or a donation of canned food.
Mayor Daley’s Clean & Green Program A citywide volunteer effort promoted by the mayor’s office and local community groups. Register by calling 311. Sat 4/17, various locations, tinyurl.com/chigreenclean.
North Lake Shore Earth Day A family-friendly green event featuring workshops on sustainable eating, healthy cooking demos, gardening info, a food-focused film festival, and a green fair. Humorist, WCPT radio personality, and master gardener Mike Nowak gives the keynote address at 9:30 AM. Sat 4/17, 9 AM-4:30 PM, Loyola University, Quinlan Life Sciences Building, 1050 W. Sheridan, 773-508-7450, luc.edu/earthday.
Think Green for Spring Chef Laura Frankel (who blogs at lauraskosher.com and serves as executive chef for Wolfgang Puck at Spertus) shares seasonal recipes as well as tips on how to shop green and kosher at farmers’ markets. Wed 4/21, 12:30 PM, Spertus Institute of Jewish Studies, 610 S. Michigan, 312-322-1773, spertus.edu, $20-$25.