Comment by PaulKeeble

At some point of transition the CO2 emissions drop to zero because all the energy at every stage comes from renewables. Solar can pay it's emissions cost back in 6 months but every solar panel company powers their factories with their own solar panels so in practice the practical emissions are reduced a lot and as mining adopts the new electric vehicles most things will tend towards almost nothing. The more renewables are adopted the shorter this emissions payback becomes. Manufacturing in the EU for example is about 55% renewables already.