Chronology, not history
I am not knowledgeable in the field, just interested. The evidence appeared to be well-marshalled, relevant, and carefully evaluated. But useful generalizations which could help evaluate the influence of climate and weather on history were scarce. I have read articles in academic historical reviews which discussed lengths of growing seasons at critical times in European history, not just end-of-growing seasons which is all this author presents. It's chronology, not history.