A decade or more back, as an expert on how the Earth’s climate had changed through geological aeons, he spent three years examining all the scientific evidence for whether human activity was now having an unprecedented effect on our climate. Having eventually concluded that it wasn’t, he spent the rest of his life arguing in a measured way that official science had taken a serious wrong turning, and that this was leading to some very foolish and dangerous political consequences that would one day be looked back on with astonishment.