@aanya, be careful how you hurl those epithets!
The total 'environmental impact' from manufacturing the batteries of a Prius far outweigh the alleged 'environmental savings' one derives from driving it. You would have to drive it far, far beyond its useful lifespan to even come close to breaking even. It is a classic feel-good, sadly typical of 'the movement'.
I'm pretty sure P.T.Barnum smirks every time someone buys a Prius!