There's a lot of time and effort that goes into Thanksgiving dinner—the turkeys and stuffings won't prepare themselves, after all. With this heavy workload comes a heavy carbon footprint, that is, a heightened number of ways for greenhouse gases to get into the atmosphere. First, there's how and where the food is grown—food grown nearby, for example, doesn't have to travel as far to your table, so trucks spew less carbon dioxide transporting it to you. (Some good table fodder for you vegans: Meat leaves a bigger footprint than vegetables.) It also matters whether you use gas or electricity to cook; if you use an electric oven, it matters whether your electricity comes from coal, natural gas, or some other source.
Taking those factors into account, Carnegie Mellon University's Paul Fishbeck, decision science undergraduate Orchi Banerjee, and chemistry graduate student Jon Wilcox found that a standard turkey dinner had the smallest carbon footprint in Vermont, with just 0.2 pounds of carbon emitted per meal, mainly due to many Vermonters' heavy reliance on renewable energy. Washington, Idaho, and Maine followed behind, with anywhere between eight and 13 pounds of carbon per meal. States that relied heavily on coal for electricity — which many of us use to cook — fared worse. Coal-centric West Virginia topped the turkey carbon footprint list at 80.1 pounds per meal, with Kentucky, Wyoming, and Indiana close behind. (The full list is here.)
Still, this is all chump change compared to one of the bigger greenhouse gas contributors: travel. Driving to a relative's house can double a meal's impact, the researchers say, and flying 600 miles—about the distance from a certain reporter's current residence to his hometown—could increase Thanksgiving's carbon footprint by a factor of 10.