The team looked at the life-cycle impact of conventional and electric vehicles.
In essence, they considered how the production, the use and the end-of- life dismantling of a car affects the environment, explained co-author Prof Anders Hammer Stromman.
"The production phase of electric vehicles proved substantially more environmentally intensive," the report said, comparing it to how petrol and diesel cars are made.
"The global warming potential from electric vehicle production is about twice that of conventional vehicles."
In addition, producing batteries and electric motors requires a lot of toxic minerals such as nickel, copper and aluminium.
Hence, the acidification impact is much greater than that of conventional car production.
"Across the other impacts considered in the analysis including potential for effects related to acid rain, airborne particulate matter, smog, human toxicity, ecosystem toxicity and depletion of fossil fuel and mineral resources, electric vehicles consistently perform worse or on par with modern internal combustion engine vehicles, despite virtually zero direct emissions during operation," according to Prof Stromman. 'Counterproductive' efforts Continue reading the main story “Start Quote
A battery electric vehicle, with electricity produced by the power generation mix we currently have in Europe, compares favourably in the magnitude of 10% or so with diesel”
Dieter Zetsche Chief executive, Daimler
With electric car production being so damaging to the environment, these cars have already polluted a great deal by the time they hit the road, the report says.
However, if the cars were then powered by electricity made from low- carbon electricity sources, they could nevertheless offer "the potential for substantial reductions in greenhouse gas emissions and exposure to tailpipe emissions" over time.
However, in regions where fossil fuels are the main sources of power, electric cars offer no benefits and may even cause more harm, the report said.