They may have some of the most covetable careers in Hollywood, but somehow actors like Jessica Alba, Leonardo DiCaprio, Brad Pitt and Julianne Moore find time to use their fame and fortune and make the world a better place. Whether their mission is keeping the ocean clean, providing nontoxic and eco-friendly products to the public, promoting sustainable farming or cleaning up oil spills, a number of stars are doing their part when it comes to the environment. LivingHealthy applauds these 16 celebrity do-gooders who are making the world a greener place to live, one day at a time!