[tlrobinson]

Indeed, that's the point I was hinting at: self-driving cars have the potential to increase carbon emissions, even the electric ones, due to increased usage and congestion.

Has Elon Musk publicly addressed this issue at all?

Self-driving cars are inevitable, so they may as well be electric. But if Tesla pulls the industry into the self-driving age before the majority of cars are electric they could actually be doing more harm than good. Perhaps self-driving cars should be required to be electric.