Methane is a greenhouse gas, until you burn it. Then it's water and CO2. The wikipedia article on methane says something like "There is little incentive to pro

Methane is a greenhouse gas, until you burn it. Then it's water and CO2. The wikipedia article on methane says something like "There is little incentive to produce methane industrially". Basically, we have too much of it already, from fracking, from livestock, from all sorts of places. Giving it to SpaceX to burn as rocket fuel makes it a less potent greenhouse gas.