5 points
I think it downplayed the importance of CO2 scrubbing, because we can tolerate low O2 a lot easier than high CO2. High CO2 is also what gives us that suffocating feeling.
It briefly touches on rebreathers near the end. The theory behind them is that the difference between the %O2 on the inhale and exhale of our breathing cycle is very little. So if you can get rid of the CO2, you can re-breathe that same air for a “long” time before it starts to get too low in O2 content and it starts to impact your survivability.
1 point
High CO2 may be what leads to that suffocating feeling, but low O2 is what makes us literally die
1 point
