August 3, 1562 a devastating thunderstorm hit central Europe, damaging buildings, killing animals and destroying crops and vineyards. The havoc caused by this natural disaster was so great, so unprecedented, that soon an unnatural origin for the storm was proposed. More alarming was the impression that it was not the only climatic anomaly at the time.

The Little Ice Age was a period of climatic deterioration, characterized in Europe and North America by advancing mountain glaciers and prolonged periods of rainy or cool weather. The term was first used by climatologist F. Matthes in 1939 to describe the most recent glacial deposits, younger than 4.000 years, in the Sierra Nevada. Later the term was adapted to a period spanning from the 16th to the 19th century (1250/1500-1850), to describe both climatic as cultural changes.

These difficult times also see the emergence of a new kind of superstition, that witches could "make weather" and steal the milk from the (starving) cows.

So we read in Bavarian and Swiss chronicles:

"1445, in this year was a very strong hail and wind, as never seen before, and it did great damage, [...] and so many women, which it's said to have made the hail and the wind, were burned according to the law."

"Anno 1626 the 27th of May, all the vineyards were totally destroyed by frost […], the same with the precious grain which had already flourished.[…] Everything froze, [something] which had not happened as long as one could remember, causing a big rise in price.[…] As a result, pleading and begging began among the peasants, [who] questioned why the authorities continued to tolerate the witches and sorcerers destruction of the crops. Thus the prince-bishop punished these crimes, and the persecution began in this year..."

Fig.1. Witches cause a hailstorm, illustration from the "De Laniss et phitonicis mulieribus" [Concerning Witches and Sorceresses], by the scholar Ulrich Molitoris, published in 1489. Curious to note that the first image showing such a scene was published in a book arguing against witchcraft, as most scholars believed that only god was able to change the order of seasons or the weather (image in public domain).

Sporadic acts of sorcery and harmful magic were known since antiquity, but only in Medieval Europe the idea of a sort of demonic conspiracy, perpetuated by sorcerers and witches against society, became common lore. Frequent storms, long winters and cold summers caused famine and starvation and so the demoralized peasants, demanding for fast actions, forced the authorities to prosecute the supposed culprits. The accusation of weather magic begins to play an important role in contemporary witch trials, even if at first it doesn't seem that it was taken too serious.

Still in 1595 the peasant Christoph Gostner, accused to have caused storms in Tyrol, argued that,

"he pushed the weather back to the highest mountains, where no cock crows, nether hay is mown, no ox lives and no flower blooms, so it could do no harm, and so the storm became just a weak rain."

Asked then why, if he had this power, he didn't prevent another severe storm, he replied that he was so "drunk that night" that he couldn't possibly have used his magic.

However soon enough witch trials, also concluding with death sentences, became common in Swiss, Austria, Poland, Germany and France. A peak was reached between 1560-1660, also coinciding with two major cold climatic phases in the Alps between 1550-1560 and 1580-1600. Last witch trials occurred 1715-1722 in Bavaria, in Swiss (1737-1738) and in Germany (1746-1749). The last European witch was executed in the year 1782, soon after (1850) glaciers started to retreat and the climate became warmer.

Fig.2. The European witch hunt occurred between ~1430-1780, with peaks in 1560-1580, 1600-1618 and 1626-1630, may triggered by an unstable and cool climatic phase, the Little Ice Age (~1250-1500/1850).

However even if we accept a role of climatic fluctuations in the history of witch hunts, it is important to note that social factors played by far the larger role. In regions with a strong government and legislation such trials were rare or nonexistent, even during climatic unfavorable phases. In rural areas, during political and social crisis, during war (the Thirty Years War in Germany occurs 1618-1648) also authorities were more willing to misuse sorcerers and witches as scapegoats. Finally in the 17th century, with the Age of Enlightenment, also the ideological, legislative and social support for witch trials soon eroded and the persecutions stopped.

Bibliography:

BEHRINGER, W. (1999): Climatic Change and Witch-hunting: the Impact of the Little Ice Age on Mentalities. Climatic Change, Vol.1(1): 335-351

BÜNTGEN, U. et al. (2011): 2500 Years of European Climate Variability and Human Susceptibility. Science Vol. 331: 578-582

FAGAN, B.M. (2000): The Little Ice Age: How Climate Made History, 1300-1850. Basic Books, New-York: 246

GLASER, R. (2008) : Klimageschichte Mitteleuropas - 1200 Jahre Wetter, Klima, Katastrophen. Wissenschaftliche Buchgesellschaft, Darmstadt, 2. Auflage: 264

JÄGER, G. (2008): Fernerluft und Kaaswasser - Hartes Leben auf den Tiroler Almen. Universitätsverlag Wagner, Innsbruck: 240

ZASADNI, J. (2007): The Little Ice Age in the Alps: Its record in glacial deposits and Rock Glacier formation. Studia Geomorphologica Carpatho-Balcanica, Vol.XLI: 117-137