I'm hosting a dinner party next week, and I'll be serving both beer and wine alongside the meal. But it got me wondering: Which has the lower carbon footprint? Beer has to be kept refrigerated, which requires energy, but shipping wine in those heavy bottles can't be good for the planet, either.
It's hard to come up with a simple answer for this one, because so many factors affect the calculation: Where was your beverage made? What's it packaged in, and how did that package get to you? How was it stored at the point of sale? Accounting for all these variables can make your head spin, but the best available research suggests that parsing out the difference might not be worth the headache.
In 2007, an analyst for the U.K.-based Food Climate Research Network attempted to tally up the nation's alcohol consumption-related emissions. Across the three categories considered—beer, wine, and spirits—the research didn't find any significant differences in greenhouse gas intensity. Wine came out with "marginally lower" greenhouse gas output than beer, though the author stressed that the tiny differences calculated—about 10 grams of carbon-dioxide equivalent per unit of alcohol—were well within the margin of error for the data. (One unit of alcohol represents about a half-pint of ordinary strength beer or half a glass of white wine.)
American drinking habits differ in some key ways from those of our friends across the pond, though. For example, Brits drink most of their beer in public establishments, whereas we tend to indulge at home. And while virtually all their wine is imported—roughly half of it traveling long distances by sea—about two-thirds of the wine we drink is produced domestically, mostly in California. Still, until someone undertakes a similarly comprehensive study on booze and the environment in the United States, the British data may be the best we're going to find. So you might as well stick with your preferred tipple and then strive to make the greenest choices in that category.
When it comes to beer, the Lantern has already weighed in on bottles versus cans: If your beer is brewed close to home and your town has a good recycling program, choose glass; if it comes from far away, stick with aluminum. A pulled pint of draught beer will always be the greenest choice.
A recent carbon footprint analysis of Fat Tire Amber Ale highlights a few other areas that deserve attention. Producing and assembling the ingredients—malt, hops, water, and fizzy CO2 bubbles—created 678 grams of carbon dioxide equivalent, or about 21 percent of the total footprint for a bottled six-pack. A significant chunk of that—244 grams—comes from the production of synthetic fertilizers for the barley and related soil emissions, so the authors suggest that switching to organic barley could make a considerable impact. (Keep in mind, though, that making a special car trip to purchase hard-to-find, earth-friendly brews might negate any upstream CO2 savings.) In Denmark, one company now brews with unmalted barley, which they claim reduces its beer's emissions by 8 percent.
Refrigeration, both in the store and at home, represented another third of Fat Tire's footprint. All things being equal, then, beers that don't need to be refrigerated—like strong beers and standard ales—should have a lower footprint than lighter beers that are best kept cold.
OK, so how about choosing a greener Chardonnay or Merlot?
First, check how it's stoppered. Though oenophiles are constantly debating the performance merits of natural corks, synthetic corks, and aluminum screw-tops, the World Wildlife Fund wants consumers to go natural, arguing that the commercial investment helps preserve threatened forests and their attendant ecosystems. (Harvesting cork doesn't require cutting down trees, just stripping off the outer bark.) Natural cork stoppers should also be less energy-intensive to manufacture than plastic or metal closures.
Food miles are probably a more important consideration for wine, since the bottles themselves are heavy—between a quarter and a half of the weight of a given case—and can travel a long way from the vineyard to your dinner table. The British study estimates that about 35 percent of wine's emissions stem from distribution.