The average ICE car uses ~4.6T CO2 per year (in gasoline). The average electric car costs about ~9T CO2 to build. Electricity in the US & the EU is currently

The average ICE car uses ~4.6T CO2 per year (in gasoline). The average electric car costs about ~9T CO2 to build. Electricity in the US & the EU is currently ~60% fossil fuels. Electric cars get >2x MPGe of the average ICE car. So if you say the average car drives ~15k miles to produce ~4.6T CO2. The average electric car driven on ~100% fossil fuels for the same amount of miles would generate less than ~2.3T CO2. Since it's only 60% fossil fuels, it's ~60% of that = ~1.38T CO2. Payoff is in about 3.33 years. In ~20 years, when we get to ~10-15% of electricity coming from fossil fuel, the payoff would be only 2.2 years. Sure, if you're driving a Toyota Prius now, and only putting on ~5k miles per year - you should probably just keep it til it falls apart. Until we get to like <30% of electricity coming from fossil fuels - I'm not sure we should be encouraging people to needlessly upgrade their car to electric (unless they're getting like 12 miles to the gallon and driving 30k+ miles per year). But, ideally, everyone would be thinking about getting at least a PHEV for their next car when they do upgrade.