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In a steady rain storm near the Washington Monument, Anastasia Bardin, 10, of New York City, left, with her mother Lyn Bardin, rallies with the Earth Action Team as part of Earth Day activities on the National Mall in Washington Sunday, April 22, 2012. (AP Photo/Jacquelyn Martin)

World celebrates Earth Day

On Sunday April 22, the world celebrates the 42nd annual Earth Day, a global event meant to celebrate the Earth and raise awareness for environmental causes. Even though it's nice to see how far we've come, images from around the planet remind us how much work is still to be done.