Less than a fortnight ago, Christophe de Margerie, the chief executive of Total, beseeched politicians to discuss energy security, not only the environment, at the Copenhagen climate-change summit in December.

One of the industry’s most plain-spoken ambassadors, he said: “Don’t go to Copenhagen only with your concern about the environment. We also have a concern over energy access. If you take only one [concern with you], we are dead and we don’t want to die.”