Clue from nature

Check that works: ergot epidemics come in cold summers

scripts/ergot_climate.py. The 117 epidemics in Hirsch's table (1000 to 1879) fall in summers colder than normal in the European temperature reconstruction: mean -0.33 standard units in the same summer, a chance result less than 1 in 1,000 (both forms: gangrenous -0.28, p 0.005; convulsive -0.36, p 0.06). They lean slightly wet in the local drought atlas (+0.19, p 0.09). So the ergot fingerprint in these data is a cold, somewhat wet harvest summer.

How it connects

This clue from nature argues against The dancing plagues were ergot poisoning dances are warm and dry, ergot years are cold and wet

This clue from nature is a clue for What caused the dancing plagues (1374, 1518 and others)?

This clue from nature explains Hirsch's table of 120 ergotism epidemics, 591 to 1879 ergot years are cold years

This clue from nature we read it in European summer temperature reconstruction (EuroMed2k, Luterbacher et al. 2016), NOAA Paleoclimatology

This clue from nature we read it in Cook et al. 2015, Old World Drought Atlas: tree-ring summer scPDSI on a 0.5 degree grid, AD 0 to 2012, NOAA study 19419

This clue from nature came from this step Tested the dancing plagues against ergot weather