The BFR runs on a mix of liquid oxygen and methane, according to Wikipedia.
Ignoring obvious scalability problems, wouldn’t it be possible to manufacture that with a pretty decent environmental footprint from various carbon neutral bio sources?
SpaceX plans to refuel the BFR on Mars with methane and oxygen produced via the Sabatier process and electrolysis [1]. They might do the same thing on Earth, even if only for the bragging rights of being carbon neutral.
Ignoring obvious scalability problems, wouldn’t it be possible to manufacture that with a pretty decent environmental footprint from various carbon neutral bio sources?