Sorry, I made some edits.No canopy at all is "required for life".
What canopy theory are you talking about? I've never eluded to any *formal* canopy theory.
I'm not so sure the canopy would have had to be that thick to exist. It only had to be thick enough to induce the pressure that was required for life.
And at the gas mix that I suspect was before the flood, that pressure would have been required.