Coffee Break Science has a nice piece about food miles which reaches a surprising conclusion – in food miles, France is closer to Chicago than California is.
here is a two-fold difference in carbon intensity (carbon dioxide, or CO2, emissions) between a bottle of wine from California and one from France (if you live in Chicago). However, while there are some small variations at the production level (CO2 emissions related to land use, cultivation, etc.), distribution is what contributes the most to the difference in total CO2 emissions. The reason for this is double: 1) shipping actually represents the largest part of total CO2 emitted during production and distribution of the bottle of wine, and 2) the modes of transport for the Chicago-France and Chicago-California shipments are different.
If I now tell you that sea freight is the least carbon-intensive mode of transport, that the French bottle of wine was mostly transported by ship, and that the Californian wine was solely shipped by truck across the US to Chicago, you can probably guess which wine you should choose to minimize the climate impact of your evening’s drink.