Under the UN's Clean Development Mechanism (CDM), researchers like Gruetter try to develop projects to reduce a nation's emissions. Part of that requires researchers to present detailed information on how many tons of carbon dioxide equivalent (CO2e) each proposed project could eliminate.
When Gruetter studied China, he concluded that, due to the nation's reliance on coal, powering a scooter in China with electricity pulled from the grid would result in emissions of approximately 20 grams of CO2e more per kilometer than running that same scooter on gas. Furthermore, Gruetter claims that, "It's worse for electric cars, in fact, as these tend to be less energy efficient – electric scooters are relatively much better than gasoline scooters while electric cars are relatively not that much better." As always, the hard truth is that electric vehicles are only as clean as the grid that supplies them with juice and, well, coal can be downright dirty.
[Source: All Cars Electric | Image: Joost J. Bakker IJmuiden – C.C. License 2.0]