Yesterday’s mail brought our May 2009 copy of National Geographic. I was surprised to see the Environment page devoted to a wine topic; surpised and a bit dismayed. It seems that our colleague Tyler Colman (Dr. Vino) has had an abstract of his study of the carbon footprint of wine transport published in NGM — kudos!

However, the ominous title “The Toll of Wine” is accompanied by a large and very misleading graphic, with disproportionately HUGE arrows representing the carbon footprint of shipping wine from Napa to NYC, relative to wine from other parts of the globe.

National Geographic’s site does not have a link to the article, and I’m not going to risk the ire of their legal department by reproducing the offending graphic (by NG staff artist Mariel Furlong) here. But Tyler Colman has it in his blog and I encourage the reader to pull it up to see what I’m talking about. Below I show a graphic of the same data, free of hyperbole: click for larger image
The top graph shows the carbon footprint data for a bottle of wine transported between the indicated origins and destinations. The relatively large footprint for moving a bottle of wine from Napa to NYC assumes routing via truck, presumably warehouse-to-warehouse via the shortest route. The relatively smaller footprints for moving wine from overseas destinations reflect the greater efficiency of sea transport. Again, I assume these footprints are calculated dock-to-dock: nowehere in Tyler Colman’s postings or in his original paper is it explicated that “last mile” carbon is included in these summations. I am going to guess that “last mile” carbon consumption has been left out of the calculus — if so, between these routes the differences are artificially larger than they would be if the costs of getting the wine to the final destination are included.

I’m interested in the indicated difference between the carbon costs of shipping Napa wine to NYC and French wine to LA — it makes no sense that the former should be greater than the latter. Tyler Colman has responded to questions about this discrepancy from commenters on his blog by noting that he and his co-author “used a port in Texas … (so) there were fewer miles driven.” No explanation was given of the reasoning behind picking a port closer to LA, rather than the East Coast ports where most Bordeaux is actually landed. The data presented in Table 1 of Colman’s original paper are distinctly at odds with the figures presented in the NGM article — the transport footprint presented for France to San Francisco is 22% greater than that for Napa to NYC; the Australia to NYC footprint presented there is 52% greater.

The bottom graph adds some much-needed context to the picture: I have included the proportional carbon footprint — a whopping 22.9 pounds of CO2 — for trucking a bundle of just 25 National Geographic magazines from NYC to Napa. Yes, I have included this as a slam against NGM for publishing a misleading graphic, depicting some questionable numbers, on paper, in a magazine with international distribution. I won’t go so far as to call out NGM as a sanctimonious, hypocritical, greenwashed old-media irrelevancy for doing so. I won’t.

At least my agenda is explicit. I object to the portrayal of California wine as somehow less eco-friendly than wine produced elsewhere, simply according to the criterion of the cost of transport to consumers in NYC — especially if the numbers are suspect. I am left to wonder what Tyler Colman’s explicit agenda is.

I’m not looking for a fight. I am deeply committed to reducing my personal and business carbon footprints. I take into consideration who is making stuff, how it’s made, and where it comes from in all my purchasing decisions. I posted a year ago about moving to lighter packaging for our products. Like others in the wine business, we are actively encouraging our direct-sales customers to choose alternatives to air shipping. I don’t sell a lot of wine on the East Coast yet, but as more rail options for small shipments become available, we will use them. I am personally disinclined to ship by sea, as I believe the ecological costs of ocean transport are greater than the oversimplified considerations of carbon cost alone.

Nevertheless, I’m reading RED, WHITE AND “GREEN”: THE COST OF CARBON IN THE GLOBAL WINE TRADE by Tyler Colman and Pablo Päster very closely, both as a practitioner trained in a “hard” science and as a concerned citizen. I find the authors’ model for calculating carbon emissions unsubstantiated. Many of their assumptions and assertions range from “questionable” to “susceptible to outright refutation.” There is also an implicit but unsubtle negative bias expressed toward high-end wine from California. In my opinion this paper lacks enough scientific rigor to have any merit with respect to moving public policy, much less public opinion.