Coal is a commodity that’s often been considered dirty, old fashioned and cheap, a humble black stone that evokes images of soot covered workers. And yet this lump of energy became the essential fuel for industrialisation all over the world, transforming societies and launching empires. But this transformative power came at a cost, as well as bringing unprecedented wealth it also brought unprecedented pollution. So how are countries dealing with coal’s legacy, and will dependence on coal carry on into the future? Joining Rajan Datar is Dr Kenneth Mathu from Gibs, University of Pretoria in Johannesburg; Dr Shellen Xiao Wu, specialist on China and author of “Empires of Coal”; the American environmental lawyer Barbara Freese who’s written “Coal: A human history”, and Darran Cowd, the manager of Kent Mining museum in South East England. Photo: coal being loaded onto a truck at a mine in China. (MichelTroncy/Gamma-Rapho/Getty Images)