You might think using your grill is a fun summer activity, but it turns out it's pretty bad for the environment. University of Manchester scientists say barbecuing releases more greenhouse gas than a 90-mile car ride-- but that varies depending on what you cook. They calculated that a barbecue for four people would release the equivalent of 800 balloons full of carbon dioxide into the air-- that’s assuming each person would eat two hamburgers, two rolls, two slices of cheese, butter, ketchup, and a bowl of strawberries with cream. Switching to chicken or preparing a vegetarian menu cut emissions significantly. Study leader Sarah Bridle adds, "Food contributes to over 20 percent of all greenhouse gas emissions. As the barbecue season gets underway, people might like some food for thought about the impact of their choices on the environment."