[_rpd]

This level of impairment conflicts with data from military studies, for example ...

> CO2 at 40,000 ppm for 2 weeks did not affect performance on multiple tests of cognitive function in physically fit young airmen

https://www.nap.edu/read/11170/chapter/5#54

but it is something certainly worth further investigation.

[antisthenes]

> Twenty-four volunteers, ages 18-23, were selected for their motivation and their excellent health.

If only we were all 18-23 years old in excellent health. The amount of abuse sustained and the speed of recovery my 20 year old self could sustain compared to my 30 year old self is truly astonishing.

When you're young, your body can compensate in a myriad ways you aren't even thinking about, that obviously weren't measured in the study.

It's a good start but not really relevant to the possible scenarios.

1. Dubious sample selection (perfect health, probably above average cognitive ability as well)

2. High levels/short term exposure rather than moderate levels & long term exposure (1+ year)

3. Tests were likely too simple and did not require a high level of abstraction/cognition in the first place.

I know sample n=1, but I've experienced increased anxiety and lower energy levels at ppms as low as 2000-3000, which you can easily encounter in a poorly ventilated room.

[_rpd]

Here's the LBNL study behind the article claims for comparison ...

https://ehp.niehs.nih.gov/1104789/

[e12e]

But seems to be in line with NASA findings:

https://thinkprogress.org/its-taking-less-co2-than-expected-...

Also, the general safety limit for co2 is around 5000 ppm for up to 8 hours - higher than that, and headaches and other effects will manifest.

I'm quite surprised that "no effect" could be seen at 40k ppm - I wonder if there were some limits to the cognitive tests (like the difference between proving a difficult mathematical theorem vs doing some Calculus).