Beef is the Hummer of all foods: Experts

When it comes to global warming, hamburgers are the Hummers of food, scientists say.

Simply switching from steak to salad could cut as much carbon as leaving the car at home a couple days a week.

That's because beef is such an incredibly inefficient food to produce and cows release so much harmful methane into the atmosphere, said Nathan Pelletier of Dalhousie University in Canada.