A new Norwegian study, “Comparative Environmental Life Cycle Assessment of Conventional and Electric Vehicles” published in the Journal of Industrial Ecology (full paper here) found that the “use phase” of electric vehicles (EVs) “powered by the present European electricity mix offers a 10% to 24% decrease in global warming potential (GWP) relative to conventional diesel or gasoline vehicles assuming lifetimes of 150,000 km. However, EVs exhibit the potential for significant increases in human toxicity, freshwater eco-toxicity, freshwater eutrophication, and metal depletion impacts, largely emanating from the vehicle supply chain.” The authors call that “problem shifting.”
The global warming potential in the “production phase” of electric vehicles is double that of internal combustion engine vehicles (ICEVs). “In contrast with ICEVs, almost half of an EV’s life cycle GWP is associated with its production. We estimate the GWP from EV production to be 87 to 95 grams carbon dioxide equivalent per kilometer (g CO2-eq/km), which is roughly twice the 43 g CO2-eq/km associated with ICEV production. Battery production contributes 35% to 41% of the EV production phase GWP, whereas the electric engine contributes 7% to 8%. Other power train components, notably inverters and the passive battery cooling system with their high aluminum content, contribute 16% to 18% of the embodied GWP of EVs.”
The authors of this paper have tried to base their estimates on a typical use scenario, but they realize that conditions vary. They discuss many caveats in their estimate in an effort to be transparent. Read the full paper for details.