In the USA, an average of 560 grams CO2 is emitted per generated Killo Watt hour.
Here's the real problem.
Of course it's important to be energy efficient, but that's utterly secondary. Reusable energy sources, or nuclear power, have zero emission.
It's not enough to reduce CO2 emission by a few percent. The source of the issue has never been energy consumption, but releasing CO2 into the atmosphere by burning fossil fuel.