Globe and Mail: Former Beatle Paul McCartney is urging the world to go vegetarian in a bid to fight global warming, and is surprised that more green groups don’t promote it. In an interview with the animal-rights group People for the Ethical Treatment of Animals (PETA), McCartney said the global meat industry was a major contributor to global warming. "The biggest change anyone could make in their own lifestyle would be to become vegetarian," said McCartney, a long-time vegetarian …