Crusading actor Leonardo Dicaprio is urging inquisitive web users to look after the environment in a new Yahoo! Answers campaign. The TITANIC star was invited by environmental organisation Global Green USA, which he serves as a member of its board of directors, to post a question online demanding solutions to global warming, pollution and other pressing eco-problems. He writes: "We can all be environmentalists. Creating communities online that are interested in discussing and embracing smart, simple and serious solutions reminds us we can all take action in our own homes and where we work." MATT PETERSEN, president and chief executive of Global Green USA, said of the celebrity initiative, "It's meant to provoke thought about what people can do in their own lives and what leaders can do to take us in a different course. "We're fortunate to have (DiCaprio) on our board because he can help shine the light on the challenge, shine the light on the experts and shine the light on the solutions."