For many decades, climate events have been viewed as one driver of cultural events during the Age of Migrations: somewhere on the Asian steppe, decline in quality pasturage successively causes one people to pressure another people to their west, and eventually the avalanche rolls into Europe.

It has saddened me to see this viewpoint associated in the American cultural wars with one party's "enemy camp", where discussion of climate as a problem is automatically associated with all kinds of unrelated policy positions. People are unaware this historical explanation was posited by hoary old (and largely long-dead) twentieth-century men who had no dog in the contemporary political divide.