Electric vehicles produce CO2 emission but the amount is largely dependent on the power plants that generate the electricity. The higher electricity demand created by the electric vehicles is met by higher fuel consumption in the power plants. Higher fuel consumption subsequently emits more CO2 emission. Coal power plant generates the highest CO2 and hydro-electric plant generates the lowest CO2.
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There is linear dependence between the emission of carbon dioxide (CO2) and fuel consumption.

Average fuel consumption and CO2 emission of automobiles using diesel oil is lower than these characteristics of cars using petrol – by 26 and 17 %, respectively, but, when burnt, one litre of diesel oil releases 2.7 kg of CO2, while one litre of petrol produces 2.4 kg of this gas.

The larger the engine displacement of an automobile, the higher its fuel consumption and CO2 emission.

The larger the automobile mass, the higher the fuel consumption and CO2 emission. When mass is in- creased by 100 kg, fuel consumption and CO2 emission grow by about 6.5 % for petrol engines and by 7.1 % for diesel engines.
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Fuel consumption and CO2 emission of automobiles with automatic transmission using petrol increase by about 19 %, compared to 35 % for such automobiles using diesel oil.

A storage battery produced with clean electricity reduces the electric car emission to 86.0 gCO2 e/km or 2.7- 3.0 times less.

Electric cars were operated on clean renewable electricity (hydro power); then, the GHG emission reduces to 11.0 tons of CO2 (47.0 g/km), which is between 5.0 and 5.4 times less than diesel and gasoline equivalents
https://t.iss.one/EnergyFactsTelegram/365

At the worst, the battery storage is manufactured in China and used in electric vehicles operated on Poland