Climate Catastrophe In The 17thC – Geoffrey Parker

I am some sort of freak for history. thats why my bookshelves are filled with books on history from the late stone age to the contemporary. The various climatic changes like the Medieval Warm period or the Roman Warm Periods as well as the earlier ones and the cold spells are pretty well documented. No thermometers then but detailed records on crop changes as well as disasters. It was warmer than today during the MWP and the RWP. Explain this alarmists.