Exactly. We just need to sum the energy costs involved in moving 1t of metal to see that no amount of electric cars compares to living close to the workplace, a

Exactly. We just need to sum the energy costs involved in moving 1t of metal to see that no amount of electric cars compares to living close to the workplace, and no "10% saving" will allow USA to divide its emissions by 7 [1]. But electric cars are a solution for the top 5% who worked a lot and deserve luxury, assuming the other layers of the population also make enough effort to avoid global warming. [1] USA has a carbon footprint of ~7 per inhabitant, so unless we assume some Chinese people should keep being restrained to 1/100th of American consumption, we'll have to come up with a scheme where most humans live at the level of an Eastern European in average. Living in a 5-floor building and working within 20 minutes distance being one of the consequences. It's not that bad, compared to the alternative.