Admittedly, he did then add a qualification that, over the next few decades, recessions and crises would knock hydrocarbon prices downwards from time to time. But the inconvenient fact (dare one say “the inconvenient truth”?) stands. Lord Stern in his July 2008 persona thinks quite differently from Lord Stern in his October 2006 persona. Either a big rise in the real price of oil is likely or it is not. As an Oxford philosophy don might say, these are mutually exclusive categories. One must ask what Lord Stern really thinks about the question and even wonder whether he has any settled view at all.

Perhaps it is unnecessary to conclude by emphasising how central the global warming debate is to hugely important issues of public policy, which have a profound bearing on the living standards of everyone in Britain and around the world. The Stern Report is full of high-­sounding admonitions and injunctions, but many of them are so global and airy-fairy that they cannot be pinned down to any tractable reality.

To give one example, we are told that “action to preserve the remaining areas of natural forest is urgent”. Has anyone told Lord Stern that, over those parts of the planet where natural forest was originally extensive, most of it was removed by man before the industrial revolution?

Alan Anderson, who interviewed Lord Stern for the Prospect article, says that, ­“listening to him”, you can believe “in a less cynical world in which decent Fabian LSE professors really are able to solve our problems”. I can’t.