redOrbit: Scientists are calling the hamburger the “Hummer” of foods when it comes to global warming, saying just switching from steak to salad could cut as much carbon as leaving the car at home a couple days a week, the American Free Press reported. Nathan Pelletier of Dalhousie University in Canada said beef is such an incredibly inefficient food to produce and cows release so much harmful methane into the atmosphere, creating the comparison. Pelletier is studying the environmental …