Not sure about your great-grandfather, but mine didn't own a car, didn't travel on vacation by airplane, and, while he may have used a stove to heat his house, he probably only used it sparingly, because coal was expensive. So I doubt his life was more energy-intensive than mine.

Now I'm wondering what the CO2 efficiency of a modern airplane per tonnage of cargo/people is compared to coal fuelled ships, obviously ignoring the aspect of _where_ aircraft emit their exhaust in the atmosphere which IIRC makes a difference.

It's nothing relevant to your comment, I thoroughly agree, but just got me curious.

Mine drove a gas-guzzling GMC CCKW 353 truck, putting out up to a kilogram of CO2 per 1 km on inefficiently planned (but scenic) routes.