Then I recalled that this was also about the time of the French Revolution (late 1700s), which I ascribe largely to the effects of a particular nadir in the Little Ice Age. (I had a post about that a while back with graphs.) A bad hail storm also happened to wipe out a large % of France's crops right before the French Revolution kicked off--when a few years of bad harvests have completely depleted your savings, and then a hail storm destroys the harvest, your attitude towards paying taxes will turn distinctly sour. You might even behead a monarch or two and try to redistribute all of the land in a desperate attempt to not starve.
I wouldn't be surprised if similarly bad weather over in Eastern Europe prompted both increased antisemitism and gloominess--I know I'd feel pretty depressed if my crops failed and then someone burned down my house.
Another nadir in the Little Ice Age occurred in the 1600s. I don't know the history of the 1600s well enough to speak intelligently about it, but I speculate that this nadir was responsible for the English Civil War and the triumph of ultra-depressing Puritanism in England during that period.
I further speculate that multi-year crop failures (or single-year mega-calamities) ought to be strongly tied to religious pessimism and political revolutions/rebellions in a way that historians could probably even quantify and make predictions with. An end to the lean times ought to promote the emergence of more cheerful philosophies, politics, or religious teachings.