I’m wondering how I might go about finding a green turkey to serve on Thursday night—or at least a greener turkey than the ones I’ve served in years past. Any tips? And please don’t recommend tofurkey —my meat-loving relatives would never forgive me.

OK, so the Lantern will refrain from recommending the soy-based option, thereby guaranteeing that he’ll receive at least a dozen incensed (albeit well-reasoned) e-mails from ardent vegetarians. (The passions evoked by this recent column were something to behold.) If you must serve a genuine turkey carcass—and the Lantern is planning to roast a garlic-rubbed 12-pounder of his own—then you can certainly try shopping for one that’s a few shades greener than its peers.

The knee-jerk answer to any green eating question is usually, “Go local,” and that would certainly seem to apply in your case. The logic is pretty straightforward: The fewer miles between farm and plate, the less energy that must be expended on transportation. Going local is easiest in the handful of states that produce the lion’s share of U.S. gobblers: Minnesota, North Carolina, and Arkansas. But there are plenty of small operations willing to meet your Thanksgiving needs, regardless of your location; use this tool to find a turkey farmer in your area.

The caveat with locavorism, however, is that the equation isn’t always simple. Assessing the environmental impact of food production requires complex life-cycle analysis, of which food miles are only one component. For example, the benefits of a shorter farm-to-market journey may be negated if the local operation isn’t as energy efficient as its distant rival. And much depends on the mode of transport: Food traveling by train may have a smaller carbon footprint than food carried on diesel-guzzling lorries.

Last year, a controversial study (PDF) argued that British shoppers would be environmentally better off buying lamb, apples, and onions from New Zealand than from domestic producers. The study’s authors—themselves New Zealanders—contended that British lambs are less energy efficient because they require trucked-in feed, whereas Kiwi lambs typically graze in pastures.

None of this means that eating locally isn’t a laudable goal. Reducing food-miles will help the environment in many cases, and the Lantern doesn’t wish to be mistaken for a hardened skeptic on the matter. But your benefits may vary according to a range of hard-to-identify factors.

Organic turkeys, which haven’t been given antibiotics, are a popular choice among green-minded consumers such as yourself (though apparently more due to the potential health implications than anything else). There is certainly a growing body of evidence that organic farming techniques may increase agricultural yields over the long haul, by maintaining soil and water quality. However, these findings apply primarily to crops, rather than animals. And you’ll have to pay a significant premium to go organic: When shopping for his bird this past weekend, the Lantern was disappointed to find organic turkeys going for at least a dollar more per pound than their Grade A counterparts. (Slate’s own Sara Dickerman discovered a few years back that the extra cost doesn’t necessarily translate into a tastier turkey.)

If cash-flow problems put organic turkeys just outside your reach this November, you can still green your festivities by breaking slightly with tradition: Instead of serving turkey, serve a couple of nice chickens. According to a landmark Cornell University study from 10 years ago, it take 13 units of fossil fuel to produce a single unit of turkey protein; for broiler chickens, on the other hand, the ratio is a mere 4:1.

So, let’s say everyone in the United States ate roast chicken instead of roast turkey this Thanksgiving—how would that impact the holiday’s carbon footprint? According to the National Turkey Federation, 88 percent of Americans will eat turkey this Thursday, which translates into around 264 million people. Let’s be conservative and estimate that each diner will consume 400 kilocalories’ worth of turkey alone (a figure that doesn’t factor in gravy or the butter used for basting).

There are approximately 1.5 million kilocalories in a barrel of oil. A quick calculation reveals, then, that filling America’s collective gullet with turkey on Thanksgiving requires 915,200 barrels of oil. Satiating our poultry jones with chicken, by contrast, would consume only around 281,600 barrels of oil. Net savings: 633,600 barrels of crude, which translates into roughly 12,355,200 gallons of gas. Since a gallon of gas produces 19.564 pounds of carbon dioxide—yes, really—then we’d reduce Thanksgving’s CO 2 output by about 109,641 metric tons.

Sounds great, huh? And it’s certainly better than nothing. But that impressive-sounding figure represents about one-thousandth of 1 percent of the nation’s annual CO 2 emissions. Which is a potent reminder of how hard it’s going to be to right our environmental ship—and, in a strange way, why it’s worth doing in the first place.

Is there an environmental quandary that’s been keeping you up at night? Send it to ask.the.lantern@gmail.com, and check this space every Tuesday.