I have been told that the high proportion of O2 and CH4 in my atmosphere are unsustainable unless constantly refreshed by an active process.
I would like to sustain the following atmospheric composition:
Molecular mass = 28.93
Rspecific = 287.38
Density at sea level = 1.08 kg/m3
Pressure at sea level = 0.81 atm
Scale height = 9717.35 m
How efficient would my photosynthetic and other carbon sequestration processes need to be to maintain this equilibrium between O2, CH4, CO2 and H2O? Keep in mind that it doesn't need to be perfect; My planet is highly geologically active and I can provide methane via volcanism (I think).
I'm trying to find examples of photosynthetic bacteria that produce a lot of methane as a byproduct of their metabolism, but nothing comes to mind right away. I'll edit it in if I find anything! I know at least if I can't find a cyanobacterium that does this, I can find a chemotrophic bacterium that does.