The US is presently doing a lot to switch over to natural gas, which has a lot less carbon-per-kWh than coal. If that's what they have in your area, the figures look better. Also good for the figures: if you happened to be doing your charging off-peak such that you're not actually adding to the emissions that would otherwise be emitted by idling power plants. (Or if you live in an area with good hydro/nuclear and the like.)

Of course, that's not really transparent to the electricity user in most cases.