A paper published in the Journal of Industrial Ecology named "Comparative environmental life cycle assessment of conventional and electric vehicles" begins by stating that it is important to address concerns of problem-shifting.[43] The study highlighted in particular the toxicity of the electric car's manufacturing process compared to conventional petrol/diesel cars. It concludes that the global warming potential of the process used to make electric cars is twice that of conventional cars. The study also finds that electric cars do not make sense if the electricity they consume is produced predominately by coal-fired power plants.[44] However, the study was later corrected by the authors due to overstating the environmental damage of electric vehicles; many of the electric vehicle components had been incorrectly modelled, and the European power grids were cleaner in many respects than the paper had assumed.[45]

Several reports have found that hybrid electric vehicles, plug-in hybrids and all-electric cars generate more carbon emissions during their production than current conventional vehicles. Study of electric car production in Malaysia estimated a compact electric car production release 5,791 kg CO2 per unit against conventional vehicles 4,166 kg CO2,[46] but still have a lower overall carbon footprint over the full life cycle. The initial higher carbon footprint is due mainly to battery production.[10] As an example, the Ricardo study estimated that 43% of production emissions for a mid-size electric car are from the battery production.[47]

In February 2014, the Automotive Science Group (ASG) published the result of a study conducted to assess the life-cycle of over 1,300 automobiles across nine categories sold in North America. The study found that among advanced automotive technologies, the Nissan Leaf holds the smallest life-cycle environmental footprint of any model year 2014 automobile available in the North American market with at least four-person occupancy. The study concluded that the increased environmental impacts of manufacturing the battery electric technology is more than offset with increased environmental performance during operational life. For the assessment, the study used the average electricity mix of the U.S. grid in 2014.[48][49]

In 2017, a report made by IVL Swedish Environmental Research Institute also calculated that the CO2 emissions of lithium-ion batteries (present in many electric cars today) are in the order of 150-200 kilos of carbon dioxide equivalents per kilowatt-hour battery.[50] Half of the CO2 emissions (50%) comes from cell manufacturing, whereas mining and refining contributes only a small part of the CO2 emissions. In practice, emissions in the order of 150-200 kilos of carbon dioxide equivalents per kilowatt-hour means that an electric car with a 100kWh battery will thus have emitted 15-20 tons of carbon dioxide even before the vehicle ignition is turned on. One of the authors, Mats-Ola Larsson, reportedly said that this is the same amount of emissions as driving a gasoline car for 8,2 years.[51] However, Popular Mechanics calculates that even if the 15-20 tons estimate is correct, it would only take 2.4 years of driving for the electric car with a 100kWh battery to recover the greenhouse emissions from the battery manufacturing. It however does not calculate in the emissions from battery replacements (battery replacement of regular lithium-ion batteries needs to be done every 2–3 years; lithium-ion batteries from cars typically last longer though).[52][53][54][55] Furthermore, two other studies suggest a 100kWh battery would generate about 6-6.4 tons of CO2 emissions, so significantly less than what the IVL study claims.[56][57]