I’ve attributed this to “fewer people, fewer distractions.” However, with a CO2 component... hmm.
Well, there is another project idea. Arduino with a CO2 sensor and plotting a running total. Or not displaying and instead have a “I feel productive” dial that would allow for correlation to the recorded data.
Nearly every standard rectangular building should be in actuality built with the energy efficient building design in mind, but we don't... out of simple mental oversight and in the increased cost in construction.
https://kammaliyaa.files.wordpress.com/2013/01/figure-11.jpg
Literally, we could save 20% to 30% in energy costs with every building with possibly only 10% to 15% increase in cost of construction, but we simply don't because we have no congregate valuation of resource consumption, only individual guilt.
CO2 is damaging to your body, I am not an expert in these matters however I know that much.
Becoming tired due to CO2 is in effect a minor form of gassing yourself, and during sleep high CO2 is bad for you and I would assume does not give you high quality sleep - same as alcohol makes can make you drowsy while also interrupting your sleep.
"Natural" sleepiness has none of these downsides.
Most of the claims are trivially verified true with a proper understanding of hypoxia and the effects on the brain.
Of course you want to be sleepy, but you don't want that sleepiness to be due to hypoxia because hypoxia is known to damage the brain.
The link you gave makes me think I actually have to dig through quite a few studies to find something supporting what you said (it's not on the first page, for anyone wondering), which is why I asked for direct sources.
A simple search of "hypoxia from excess CO2" brought up https://en.wikipedia.org/wiki/Hypercapnia, which also support the claims.
Please, for the love of god, learn to google properly: http://www.catb.org/esr/faqs/smart-questions.html
During the lecture he mentioned the figures for CO2 concentration that led to symptoms, e.g. dizziness, sleepiness etc.
The reading at the end of the lecture showed that it was over the recommended limit, and well beyond the threshold that causes people to get sleepy and lose concentration. (I believe it was less than 400ppm at the start and thousands ppm afterwards?)
A simple demonstration using an older building crammed full of students in a closed space, but it was apparently quite impactful in showing the students how there are a lot of features of interior design architecture that aren't really addressed and are only coming to the fore recently.