April 22 is the 40th anniversary of Earth Day (Poor Earth. Kickin’ around for 4 and half billion years and only in the last 40 does it get a day for itself) and I’m sure you’re looking for some way to participate. The EPA has a nice list of events, broken out by region. Check that out.

Plus, the Dow Live Earth Run/Walk for Water will be held in nearly 100 cities across the globe April 18. Get in shape while helping raise awareness of the need for clean drinking water.

And here’s a few other events to consider in various Captivate markets:

Atlanta
-- Get down and dirty – but clean your conscience – with the BeltLine Cleanup, set for April 17. Make your city beautiful, Atlantans!
-- Bring the kids to Earth Day Kids Fest at the Chattahoochee Nature Center April 17 and teach the basics of being green.
-- EarthShare of Georgia’s Earth Day Party on Land, on the big day itself, features music, food, lots of green info and an auction.

Boston
-- The Sustainable Living Expo marks its seventh year April 17 in Hull with exhibitors of all sorts of green energies, focusing on wind. There’ll be tours of the Hull Wind Turbine, recycling demos and hybrid vehicle rides.
-- Franklin Park Zoo’s Party for the Planet, set for April 18, celebrates Earth Day with crafts, activities, animal encounters and environmentally-friendly exhibitors.
-- Garden in the Woods in Framingham is marking Earth Day by waiving entrance fees on April 24. Take a guided walking tour and participate in family activities like face-painting and bird-feeder making.

Chicago
-- The National Geographic Speaker Series, at the Field Museum, features photographer James Balog on April 13. He’ll show his latest work, which documents melting glaciers.
-- A 5K run/walk, followed by a green living expo, will be held April 24 at Humboldt Park. Expect music, food and “environmental education and fun.”
-- The Wolfe Wildlife Refuge will be the site of nature walks, hybrid car and other green displays, and kids’ activities April 24.

New York
-- NYU is hosting a week of events, from movie screenings to street fairs to live music.
-- GreenHomeNYC’s Green Building Tour of the Gen. Colin Powell Apartments in The Bronx is slated for April 24.
-- South Bronx Earth Fest is April 24.
-- Eco-Festival 2010 at Kingsborough Community College in Brooklyn is April 27-30.

San Francisco
-- San Fran gets things kickin’ early with the Spring Green Festival this weekend. With more than 200 speakers and artists and multiple pavilions on green living, this is sure to be a huge event. Even the major will be there!
-- People’s Earth Day at India Basin Shoreline Park on April 17 will feature an educational theater production, restoration projects, live music and plenty of food.

Washington, D.C.
-- D.C.’s big day really isn’t until the weekend, when groups from the EPA to Earth Day Network will hold rallies on the National Mall.