E-Mail IMAGE: Benjamin K Sovacool, Professor of Energy Policy in the Science Policy Research Unit (SPRU) at the University of Sussex Business School. view more Credit: University of Sussex The hidden social, environmental and health costs of the world's energy and transport sectors is equal to more than a quarter of the globe's entire economic output, new research from the University of Sussex Business School and Hanyang University reveals. According to analysis carried out by Professor Benjamin K. Sovacool and Professor Jinsoo Kim, the combined externalities for the energy and transport sectors worldwide is an estimated average of $24.662 trillion - the equivalent to 28.7% of global Gross Domestic Product.