The Prius’s reputation as a “green” car is completely undeserved. The culprit is its nickel metal hydride battery.
The nickel is mined in Sudbury, Ontario, and smelted nearby, doing damage to the local environment. The smelted nickel is shipped to Wales, where it is refined. Then it is sent to China to be made into nickel foam. Then it goes to Japan, where it is made into a battery. Then it goes into cars, some of which are shipped to the United States and some of which go to Europe. All of that seaborne transport consumes a lot of fossil fuel.
via washingtonpost.com.