Coal combustion is not only the single most important source of CO2, accounting for more than a third of global emissions, but also a major contributor to detrimental effects on public health and biodiversity. Yet, globally phasing out coal remains one of the hardest political nuts to crack. New computer simulations by an international team of researchers are now providing robust economic arguments for why it is worth the effort: For once, their simulations show that the world cannot stay below the 2 degrees limit if we continue to burn coal. Second, the benefits of phasing out coal clearly outweigh the costs. Third, those benefits occur mostly locally and short-term, which make them useful for policy makers.