And now for a truly important question: What is the greener option, in terms of carbon footprint, for a hypothetical wine-drinking citizen of Ohio: a California merlot from Napa county, a cheap Australian bottle of Yellow Tail shiraz, or a French bordeaux?
To answer this query, we first need to know whether you live east or west of Columbus, Ohio. Because, as explained in the fascinating new working paper, "Red, White and 'Green': The Cost of Carbon in the Global Wine Trade," the most important factor involved with calculating the carbon footprint of wine is the energy cost of transporting glass bottles around the world. Unrefrigerated container shipping by sea is best, air freight is worst, and trucks trundle on somewhere in between.
This means that east of Columbus, it is less injurious to drink wine shipped across the Atlantic than trucked from Napa. In New York, if you want to "drink locally" -- think France.
Other things to consider: Magnums are more efficient. Organic doesn't make much of a difference, although if a carbon tax or cap-and-trade system raises the cost of petrochemical inputs to fertilizer, sustainable agricultural practices may make more economic sense. The absolute worst scenario: having your case of red shipped by overnight express air freight from your favorite cult Northern Californian winery.
Authors Tyler Colman and Pablo Päster, who we assume are both member of the American Association of Wine Economists, under whose auspices the paper has been published, offer some proactive recommendations for winemakers who want to reduce their carbon footprints, and thus alleviate the burden of guilt for wine-drinkers.
Wine producers can minimize the carbon impact in the winery and the vineyard following several conclusions that flow from this analysis. First, cutting down forest or converting highly productive farmland to vineyard should be avoided but converting overgrazed land may have a positive impact on restoring some biological productivity to a parcel. Second, minimize agrichemical use. Third, improve irrigation to maximize water efficiency. Fourth, use imported oak barrels longer, switch to local oak barrels, use oak chips, or, most sustainable of all, use no oak. Fifth, improve the efficiency of winery operations and use renewable energy and biofuels. Sixth, procure recycled-content bottles, manufactured regionally or consider non-glass packaging options. Seventh, reduce shipping distance and select the most efficient mode possible, which means not shipping by air. Finally, once all economically feasible carbon emissions mitigation measures have been put in place, purchase verified carbon offsets for all remaining activities.
It all sounds good, except, maybe, "non-glass packaging options." Tetra-Pak juice box wine to stop global warming? Some people are having a hard enough time dealing with screw-tops instead of corks. Even in California, there may be sacrifices that simply ask too much.