that is -- emission levels of greenhouse gases.

Hydrogen for a fuel cell car has to come from somewhere. Right now, it comes as a byproduct of industrial petroleum processes. If it were created by using electricity to split water and the electricity came from green sources, then yes. However, in order to have a hydrogen powered system of transit, we need to build an infrastructure for it, which will take immense resources. The infrastructure for an electrically powered transit system already exists.Both are exciting and promising new technologies, but for the time being I think that electric is just more feasible.

Electric vehicles have emissions levels lower than hybrids because currently hybrids still rely partially on gas combustion, which is a less efficient process than the processes which fuel our power grid.Theoretically, hydrogen cars could produce lower emissions if they obtained their fuel by means of electrolysis. However, this process is currently so inefficient that it takes so much energy to separate the hydrogen that it would create higher emissions than both.So theoretically electric vehicles could have emissions levels between hybrids and hydrogen cars, but the reality is that hydrogen cars are several decades away from being feasible. In the meantime, electric vehicles produce the lowest emissions. See this discussion for further details:http://answers.yahoo.com/question/index;_ylt=Am2pWOxnFjdvlJ7qKN05Uwzty6IX?qid=200708 27141524AAc0HaA

I know why you asked - because electric vehicles are supposed to have zero emissions! The only explanation for GHG emissions to be assigned to electric vehicles must be the amount of GHG generated by the power plant when it generated the amount of electricity to recharge the electric vehicle. So the "emissions" actually took place at the power plant and not at the vehicle. And those emissions levels are between gas-electric hybrid cars and fuel cell type cars.

A pure electric car is not pollution free. It is not pollution free because unless you happen to have a solar power generating station can to recharge your electric car, you have to use conventionally created electricity. Conventional electricity is created using fossil fuels. Burning of fossil fuels releases carbon into the atmosphere increasing pollution.

Electric cars are 'fuelled' by the electric power companies. So whatever fuel source they use to generate the power to charge electrics gets to transfer its 'carbon footprint to YOUR vehicle.