"Have more kids to save the culture" seems 100% at odds with saving the planet, as does expending 51 tons of CO2 to make the statement.
If everyone lived like Elon the planet would be ruined and the only hope would be colonizing Mars...but there's no way to get everyone off the planet, especially if we have 11 kids each.
I just don't see a coherent ideology except "save the planet long enough for me to off it."