With the number of vehicles on the world's roads expected to grow to 2.9 billion by 2050, steps must be taken to reduce the CO2 emissions from transport. Battery electric vehicles (BEVs) can help achieve this. This study aimed to determine the CO2 emissions stemming from BEV operation in different countries and to compare those CO2 emissions to the emissions from similar vehicles based on internal combustion engines (ICEs). This study selected four ICE-based vehicles, and modeled BEVs based on the specifications of each of these vehicles. The modeled BEVs were run through a simulation to determine their energy consumption. Their energy consumption was combined with data on the CO2 intensity of the power generation mix in different countries to reveal the emissions resulting from BEV operation. The CO2 emissions from the BEVs were compared to the CO2 emissions for their ICE-based counterparts. Amongst the results, it was shown that for China and India, and other countries with a similarly high CO2 intensity, unless power generation becomes dramatically less CO2 intensive, BEVs will not be able to deliver a meaningful decrease in CO2 emissions and an increase in the penetration of BEVs could actually lead to higher CO2 emissions. (C) 2010 Elsevier Ltd. All rights reserved.