He underprices the costs since it's impossible to put a price on extinction risk. He needs to read The Black Swan. One of its principles is never to trust the analysis of someone who has no skin in the game. That's why I said don't believe him until he buys his skin in the climate change game in the Maldives, Tuvalu or similar location.

His estimate of the costs is a form of accounting fraud due to underestimating asset impairment risks. Most accounting fraud is perfectly legal, as shown in Thornton O'Glove's Quality of Earnings.