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Comment by sparker72678 | Hacker News Reader

> So Karnauskas worked with a mechanical engineer and a cognitive neuroscientist to make back-of-the-envelope calculations based on the Harvard findings and projections about rising carbon-dioxide emissions.

> They created a model of a classroom full of elementary school children, with the appropriate breathing rates and room ventilation. (Karnauskas said the results would be similar for any group of people.) Then they looked at what would happen in two potential emissions scenarios projected by the Intergovernmental Panel on Climate Change (IPCC).

> The results showed that in a business-as-usual scenario, in which carbon emissions continue to rise, humans would score 50% lower on measures of complex cognitive ability by 2100. For more basic cognitive measures, performance would drop about 25%.

Not exactly a rigorous model.

Edit: Which doesn't mean there isn't a problem, but this sort of article doesn't seem helpful to me.

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Yeah I really don't get how we're supposed to interpret "50% lower". Intelligence is barely ordinal to begin with. Also ventilation when done properly isn't just some fixed rate, we already target air changes per hour and CO2 levels to prevent indoor air in an office environment from becoming too stagnant. This just means we would need to increase the ventilation, not that it wouldn't work at all.

> we already target air changes per hour and CO2 levels to prevent indoor air in an office environment from becoming too stagnant

If you ever take a Co2 sensor into a standard office environment or even your home, you're in for a bit of a shock.

https://www.theguardian.com/environment/2019/jul/08/indoor-c...

Well, 50% lower as measured by scores in the tests they used. And yes of course this might be mitigated by better ventilation, but you have to know or suspect there’s a problem first in order to effectively mitigate it. The fact that an effect can be countered isn’t a valid criticism of a study showing an effect.

So I do agree with the critical comments, to the extent that this isn’t enough proof and we need better studies, but the theory seems credible and worth further study. But the dismissive attitude makes no sense to me, and if increased CO2 levels do have a proven effect on cognition, and CO2 levels are actually on track to rise to levels with a significant effect, that’s a really big deal.

Big clever complicated models are important and useful of course but I think this sort of back-of-the-envelope calculation is important too. They can give a clue that a model isn’t massively wrong which is useful when developing a model and when replying to a complaint like “this model is so big and complicated that no one could have any confidence in its predictions.” It’s also something useful in directing further research.

I guess the point of the article is to say “here’s an implication of climate change that you possibly hadn’t thought/heard about.”

I know I’m inclined to think this is a serious issue and the effect of present indoor/city/outdoor CO2 levels on cognition is something I was concerned about anyway. CO2 levels outdoors are already 1/3 higher than 100 years ago and something like double the level of 10,000 years ago. And people spend more times indoors in better-sealed houses and denser offices.

RCP8.5 strikes again...

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