Guardian: Last week, I shared dinner with some of the most powerful men and women in the world. It was a gathering of chairmen and CEOs of major European and global companies, titans from the energy, mining and retail sectors, all there to discuss the greatest challenge facing civilisation – climate change. Almost as one, they spoke of the need for governments to take action to reverse global warming and for the carbon to be taken out of the world economy. For most people faced with images of …