Think changing the world is impossible? Think again. From a polio-stricken musician who’s spreading the word about clean water in his native Mozambique to a pair of Ecuadorian activists taking on Big Oil, this year’s seven Goldman Prize winners prove that a little heart and a lot of sweat can make a big difference.

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Each year, the Goldman Prize — founded in 1990 by San Francisco philanthropist Richard Goldman and his late wife, Rhoda — recognizes extraordinary efforts by individuals around the globe. Often putting themselves in danger, and always committed to their respective causes, the winners put a truly human face on the environmental movement.

This week they’ll gather in San Francisco and Washington, D.C., for a hard-earned moment in the spotlight. And with a $150,000 prize to take back to their home countries, they’ll earn not only a prestigious honor, but concrete resources to put toward their continued battles.

(Read about the Goldman Environmental Prize winners from 2007, 2006, 2005, 2004, and 2003.)