Another source of greenhouse gas

By Nina Shen Rastogi
Tuesday, December 15, 2009

I'm planning a big holiday shindig, and I was going to put out my usual enormous cheese-and-cracker spread. This year I've been wondering: What's the environmental impact of cheese?

Cheese is certainly one of life's great pleasures. (The Lantern is with Liz Lemon of "30 Rock" on this point.) But there's no doubt that cheese of any type -- pasteurized or not, made from the milk of cows or goats or sheep -- has a significant impact on the environment compared with other food products. So by all means enjoy your spread, but it might be worth scaling back a bit for the sake of the planet.

It turns out that cheese may do as much harm to the environment as some kinds of meat. Based on figures from Sweden, making a 1.5-ounce serving of cheese might be expected to produce about 16 ounces of carbon dioxide equivalent. Depending on which study you consult, a two- to three-ounce serving of cooked, boneless chicken should yield between 4.3 and 31 ounces of CO2 equivalent. (You'd get about the same number of calories from each.)

Why is cheese so resource-intensive? As we've discussed before, raising a milk-bearing animal generates a significant amount of greenhouse gases, thanks in large part to the methane those ruminants emit. Feed production also contributes to global warming, and animal waste has implications for both water and air quality. The good news is that the American dairy industry hopes to cut its greenhouse gas emissions by 25 percent in the next 10 years, through such strategies as adjusting cows' diets and installing methane digesters to turn manure into electricity. Some farms are already implementing these measures, so you might want to look at where cheesemakers are getting their milk.

The Lantern realizes it won't be easy to track down this information. But if the eerily well-informed salespeople at her local fromagerie are any indication, provenance is becoming more important in the cheese world, at least on the fancy end of the spectrum. And while artisanal cheeses aren't necessarily going to be greener than the mass-produced kind -- particularly given that small cheese plants tend to be less energy-efficient than large ones -- you will be able to learn more about your cheese if it comes from a small producer.

What about the species? Generally speaking, sheep cheese is going to be worse for the planet than cow or goat varieties. Researchers from a Finnish government research institute estimated in 2008 that greenhouse gas emissions per unit of cheese would be roughly the same for cows and goats. (Cattle emit much more methane but make up for it with their increased milk yields.) A sheep, however, might emit twice the methane of a cow or a goat per unit of milk produced. An exact comparison would require more information about the husbandry practices being used in each case, though, and studies from New Zealand indicate that some sheep are less gassy than others.

Finally, the less processing a cheese undergoes, the easier it'll be on the planet. All things being equal, younger cheeses are more energy-efficient than older ones, because of the electricity required to keep cheeses at a cool, steady temperature as they age. (That's true in the United States, at least. In Europe, they make greater use of cool underground caves.) Likewise, soft cheeses will tend to be greener than hard ones, since the latter usually require more milk, more extensive aging processes and longer cooking at higher temperatures. (The caveat here is that individual cheese plants can vary widely in terms of their efficiency, which may alter the equation.)

Steve Zeng, a dairy researcher at Langston University in Oklahoma, singles out feta cheese as one of the best options in terms of processing impacts and notes that chevre, brie and Camembert are also pretty green. Same goes for American's top-selling cheese (mozzarella), since it doesn't require any aging.

Far more important than the kind of cheese you choose, though, is finishing whatever you take home. Thanks to America's deepening love affair with fancy cheese, it's easy to get chunks cut to order, which may cut down on the amount of associated packaging. So while you're shopping for party provisions, think carefully about how much you and your guests are likely to consume, and plan to store any leftovers properly. A recent study noted that Americans toss out a shocking 40 percent of the food we produce -- a figure worth keeping in mind during this festive season of gluttony.

Is there an environmental quandary that's been keeping you up at night? Send it to, and check this space every Tuesday. Read previous Green Lantern columns at here.

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