If you don't heat or cool them yes, it reduces CO2 emissions. No, it's not preferrable.
Wood, Straw Bale, Earth. This all works even in high rise building.
I live in a high rise building made out of concrete and know plenty of people who live in wood buildings. I'll pay double to not have to deal with the problems wood buildings have.
How often do you replace your tent? Does it come from china?