As if you need another reason to feel guilty about chowing down on Thanksgiving Day, consider this: researchers at the University of Manchester in England figure that a turkey-n-trimmings feast for eight produces approximately 44 pounds of carbon dioxide emissions. About 60% of that planet-warming gas comes from the life cycle of the turkey, alone. And that doesn't include drinks.



Leave it to the Brits to rain on our traditions. But it was brought to my attention by the Washington-based Center for Food Safety, which wants Americans to lay off food produced by "industrial agriculture" for the sake of the planet, if not their health.



"Choosing the type of food we eat - organic versus conventional meats and veggies, makes a great difference in greenhouse gas emissions,'' says Debi Barker, the center's international director. About 14 percent of all greenhouse gas emissions are connected to industrial agriculture methods, she contends, with much of those related to the use of chemical fertilizer on crops. By one estimate, half of all methane emissions - another powerful greenhouse gas - come from concentrated animal feeding operations, she adds.



"Our take on that is to empower ourselves," Barker says. "If you're buying organic, you're really taking a bite out of climate."



Not everyone agrees that organic is the best lifestyle response to concerns about climate change. Mike Tidwell, head of the Chesapeake Climate Action Network in Takoma Park, says the research shows that the best way to shrink one's carbon footprint in what you eat is to simply consume less meat. Raising beef generates the most greenhouse gases by far, but farm-raised fish and fowl, including turkey, are "still high-impact," Tidwell says.



"While I respect the idea of being a locavore and getting all your meats organically and locally," he says, "the studies are emerging that whether the meat is grown locally or far away, it still requires a lot of resources, including carbon resources.... If you really want to have a low-impact diet in terms of change, then you just have to eat a lot less."



With a singular exception, Tidwell practices what he preaches. Though raised in the South and a professed lover of barbecue, he says he's gone vegetarian the past 10 years out of concern for the climate.



So what's Tidwell eating for Thanksgiving? "You caught me, with my one exception," he answers. Turkey with cornbread stuffing and all the rest. "We're eating at my wife's sister's house (in Easton),'' he explains. "I'm not in control of it."



Not that he's apologetic, either. "One day a year I wake up in the morning, and I consciously decide to eat meat, and that's Thanksgiving Day. So .. I eat turkey, and I do not get cheated. I enjoy it. But the rest of the year I'm a vegetarian."



If you could care less about climate change, there are other reasons to ponder the environmental footprint of your turkey treat. For instance, it'll take at least 915,200 barrels of oil to produce and ship all the turkeys Americans eat, according to the Center for Food Safety.



Moreover, there's the matter of all the nitrogen and nitrous oxide released into the environment by raising (and eating) fowl - nothing to cluck about here in Maryland, where the Chesapeake Bay is choking on all the uncontrolled nitrogen produced by our driving, our obsession with green lawns and our seemingly insatiable craving for cheap poultry.



But don't let that spoil your appetite. On this one day, even the greenest of activists seems to relent a bit. If they're okay with it, why not you? So compost your table scraps if it makes you feel better, pardon a turkey for another meal and skip the heaping side dish of guilt this time. Have a Happy (if none too green) Thanksgiving!