ABC News: If “An Inconvenient Truth,” Al Gore’s Oscar-winning 2006 film on global warming, left audiences depressed about the planet’s future, a new film from the same executive producers is designed to lift spirits. “Climate of Change” premieres at New York’s Tribeca Film Festival Thursday — Earth Day — and focuses on the efforts by individuals from around the world to reduce their personal carbon footprint while fighting business interests they say threaten the environment. “I …