Climate change is one of the instances, Stiglitz and Stern told me in an email, in which “it is generally agreed there is extreme risk — we know there are some really extreme events that could occur — and we know we cannot pretend (i.e., act as if) we know the probabilities. Nordhaus’s work doesn’t appropriately take into account either extreme risk or deep uncertainty.”

In other words, the economist who has been embraced as a guiding light by the global institution tasked with shepherding humanity through the climate crisis, who has been awarded a Nobel for climate costing, who is widely feted as the doyen of his field, doesn’t know what he’s talking about.