It is a fact that electric cars don’t pollute atmosphere while running on roads, as they are zero emission (tailpipe emissions) vehicles and also eliminate oil. But one must understand that they run on electricity. So apparently though they look environment-friendly, if the electricity required to charge the battery is coming from a coal fired power plant then the entire scenario needs to be re-looked carefully with proper research and analysis. As the coal fired power plants cause very high air pollution.
The recent study conducted by the Swedish Environment Institute shows that car battery manufacturing at the factory leads to very high CO2 emissions. For each kilowatt-hour storage capacity of typical lithium-ion batteries, emissions of 150 to 200 kilograms of carbon dioxide equivalent are generated. For example, when one buys Nissan Leaf with 30 kWh battery, CO2 emissions of approximately 5.3 tonnes has been released for manufacturing the battery, quite a scary figure! This calculation is based on the assumption that the 50% electricity used by the factory manufacturing the batteries, comes from fossil fuels which is a source of greenhouse gas pollution.
So it all depends on the source of electricity at the manufacturing end. In the states like California where the world electric car manufacturer Tesla is located the above calculation becomes void as the energy mix, there is pretty green. California has the highest proportions of clean electricity in the country. So to avoid climate change effects, it is a necessity we have to produce the electricity by the environment-friendly way. And also tighter pollution control norms need to be forced on power plants producing electricity by burning fossil fuels such as coal.