The production and recycping/disposal co2 costs are much heigher than u would expect. U cant get around these u cen reduce them but there are proccesses where u can not avoid pumping greenhouse gasses into the atmosphere (these can be handled by the enviroment if we hadnt been making more than nessasary for so long). And electric cars are very rarely charged exclusivly on renewables and even if they are u need to account for the carbon cost for the lifecycle of those renewables as well. U also need to account for energy losses cos thermodynamics is a bitch etc etc.

How i did calcs: Talking specificly about the case i was arguing for before where u already have a car. U can get estimates of co2/kg for producion and recycling of a car. Using that and the cars weight get its production and disposal costs. U have already "paid" the carbon cost of manufacture for the car u already own so u only have the operation. But if u where to buy a new car u have both the production of the new one and the disposal of the old one(why reduce reuse recycle is in that order) to account for. Add the yearly cost as ur linear factor. Both can be plotted on a graph and the intersection will be the time period where u break even.

If u also put electric cars on the plot they are actually worse than ur average petrol car (currently with our non renewable grid) cos u have all the losses from energy transformations electric car goes: chemical energy to heat energy to mechanical energy to electrical energy back to chemical energy (ur battery) to electric energy to mechanical energy opposed to a petrol car which goes chemical energy to heat energy to mechanical energy.

An electric car run purly on renewables might have a lower co2 cost but lithium mining is disasterouse for the enviroment. And cobalt mining is power by slavery. Its a fucking disaster all round and at this point the option with the lowest cost to humanity is looking like sacricing millions or poor people to the greater good untill we have enough rare earth minerals to have a proper recycling lifecycle. Its like the early days of aluminium extrordinarily expensive and bad to produce but once produced very easy to recycle.