Earth Day 2012 around the world (PHOTOS)

Earth Day was celebrated around the world this past Sunday, with fanfare and environmental action brought to the forefront of global conversation.

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The day's genesis can be traced back to former Senator Gaylord Nelson of Wisconsin, who, after witnessing the catastrophe of the 1969 oil spill in Santa Barbara, California, called for an environmental teach-in, or Earth Day, to be held on April 22, 1970. Over 20 million people participated that year. The event has since spread, including hundreds of nations and peoples participating in various ways.