This economist article had a nice summary on this topic, 2014 (not about the same report, however). http://www.economist.com/news/science-and-technology/216367

This economist article had a nice summary on this topic, 2014 (not about the same report, however). http://www.economist.com/news/science-and-technology/21636715-why-electric-car-may-be-much-dirtier-petrol-one-cleaner-what http://www.economist.com/news/science-and-technology/2163671.... The culprit is coal.