Strong volcanic and climatic shocks on early modern wine production

Wine is a particularly climate-sensitive crop for which long documentary series are available in much of Europe. Most studies of climate–wine growth relationships have hitherto utilised grape harvest date series. We instead investigate the climatic signature, and impact from volcanic forcing, on two long annual wine harvest quantity records from the Moselle Valley, in present-day Luxembourg, close to the latitudinal limit of commercial wine agriculture in Europe. A strong positive relationship between reconstructed temperature, especially summer temperature, and wine production quantities is found in our data that extend from the mid-fifteenth century until the end of the eighteenth century. Extremely cold or wet years show clear imprints on the wine harvest quantities. Large declines in the wine harvest – sometimes even total harvest failures – occurred after volcanic forcing events. The most significant decline in wine production quantities occurred during the first year after a volcanic forcing event. However, persistent wine production decline is evident over several consecutive years following larger volcanic forcing events. We compare the signature of Moselle Valley wine production declines following volcanic forcing events with corresponding tree-ring growth declines in different regions of Europe. It is evident that wine production shows a stronger and more distinct downturn following volcanic forcing events, even more minor ones, than tree-ring growth does in central Europe. Possible mechanisms for this behaviour are explored and discussed.