Also, it's kinda suspicious that he's going into his office for 22 years after his retirement: It's more like the university is a replacement old folks home for him. This is all well and good and what probably keeps him sane, but if he means to repay the hospitality with being maverick and going against good science ... then shove him out, I say. Let him prove that humans are not the cause of this. Everybody can put up some reasoning, of which the assumptions are totally false.