Not the case as any incremental load on electricity requirements must be met by fossil fuels. Think about it for a while. The key word is incremental.
(Even if you use your own rooftop solar panels to charge your EV, you are still increasing fossil fuel usage as you could have put that electricity into the network and driven an ICE car. Net result is an EV running puts as much CO2 into the atmosphere as an ICE. If you want to reduce CO2 emissions, buy a hybrid car. If you want to reduce CO2 emission further, use public transport. If you want to reduce CO2 emission even further use a push bike or walk.)
