Leonardo DiCaprio is urging President Bush to support the environment by attending the Earth Summit in Johannesburg, South Africa, later this month. "Mr. Bush, we're asking for your support, to be the president that looks towards the future," DiCaprio said Monday. The Titanic star blasted Bush's environmental record, calling the U.S. the planet's "biggest polluter." There's no word if Dubya plans to attend, or if he even knows who this Leo fella is.