Rex Tillerson, ExxonMobil's chairman and chief executive, may have softened the fiercely sceptical stance on global warming of Lee Raymond, his predecessor. But he retains the corporate appetite for plain speaking.

Attacking the energy bill now passing through the US House of Representatives as defying "logical or rational thinking", he staked out his position as the energy industry's most vocal critic of the claims made for renewables, and defender of fossil fuels.