Recently the Association National d’Etude et de Lutte contre les Fléaux Atmosphériques (ANELFA) announced the purchase and installation of 125 silver iodide generators in a no-holds-barred effort to thwart the occurrence of destructive hail storms in the vineyards of Burgundy. On the surface this would appear to be a wise investment but is there an ancillary cost? At least one commentator thinks so.
Wine-influencer Tom Wark in his daily blog Fermentation asks whether the use of such generators constitutes an abrogation of the principles of terroir:
“. . . there is no question that the “Hailstone Shield” is altering the effect of the very unique Burgundy terroir. It begs the question if the Burgundians could use technology to increase their average temperature by a degree or two, would they? I suspect there would be a number of growers that would jump on the opportunity.”
This is an odd take given that so many “terroir defeating” practices are more or less accepted without controversy. What about netting to combat both hail and birds? Or smudge pots and fans to mitigate frost? Is terroir defeated by picking before the arrival of anticipated storms? Does the introduction of beneficial insects or native vegetation compromise the “play it as it lays” philosophy? Personally I don’t see a difference between any of these methods and their potential to compromise terroir.
The better question to ask is whether the literal fall-out of silver iodide back onto the earth should disqualify organic and biodynamic practitioners from certification and, perhaps more importantly, whether residual amounts linger in the soil or the wines.
One local vigneron summarizes his feelings in this way:
“There is no way I would use this technique if I thought it harmful.”
The science seems to agree. The Weather Modification Association (WMA) in their position statement on the environmental impact of using silver iodide as a cloud seeding agent dated July 2009 concludes:
“The published scientific literature clearly shows no environmentally harmful effects arising from cloud seeding with silver iodide aerosols have been observed, nor would be expected to occur. Based on this work, the WMA finds that silver iodide is environmentally safe as it is currently being used in the conduct of cloud seeding programs.”
While silver iodide may be technically safe (there is still some dispute) it is an inorganic compound that may run afoul of Demeter and other biodynamic arbiters. The case can be made that silver iodide is a synthetic treatment designed to eradicate the meteorological pestilence that is hail. It might be useful for them and others to weigh in on this topic before any real damage is done.
Now let’s pray for a fruitful and less dramatic growing season for all those adversely affected the past few years.