‘ThinkProgress ‘s at least a minion of the mainstream, my kid sent me an article being sent around his company. This is a clever paper if you appreciate buttressing false claims with solid fact. I find them everywhere, would do nothing else if I analyzed them all.
The relationship of CO2 to cognitive function is very likely solid, although some of these groups were funded by various global warming advocates, and big pharma shows how easy it is to get the results you paid for. (Really, worst case is they fund 20 people sworn to secrecy, and publish the .05 probability result they will get 1 out of 20 times, but I believe they rarely have to fund more than 2.) Big-pharma paid for drug studies are the lowest-reliability when replications are done, are always the ones with the highest estimated therapeutic effects and lowest side-effects. That comparison hasn’t been done for AGW funders but people are people and only fools are optimistic about groups of people controlling money and power.
So there is an effect of CO2 on cognition, and I would extrapolate that it has increasing effect as we age, because the blood’s buffering ability falls off. But the level at which CO2 effects on cognition kicks in, the amount of cognitive decline, etc. is a different issue. There was an oxygen bar craze that went around a few years ago, maybe CO2 accounts for it, and certainly people’s perceived need for cognitive enhancers is greater than ever. And for I know, some nootropic manufacturer is funding these. Thus, more hidden motives of all kinds, and it is a safe prediction that issue will take some time to get the baseline information straight. Interactions between the many variables will confound the research and take many conferences to straighten out, no matter how obvious these effects, it is the fate of every new psychological effect.
Meanwhile, here in the present, connecting CO2 indoor levels to indoor and outdoor ‘perceived air quality’ is a correlation study. In both, the CO2 is easy to measure, and a good proxy for those individual assessments, but the amount of CO2 is obviously correlated with the number of people, who emit many different chemicals into the shared air while sitting at desks. Outdoors, internal combustion engine exhausts and chimneys produce CO2 along with many other chemicals. Everyone is interested in a proxy measure, because it is much harder to measure all of those other sources of bad air.
But these clever people tie the effects of CO2 into AGW thinking. In that bit of the argument, rising CO2 levels is in itself air pollution, a degradation of the quality of the air. Plants don’t think so, plants like it, and both plants and people would rather 450 ppm CO2 from a the freshest outdoor air than 450 ppm CO2 produced entirely by people in a confined space, because ‘fresh outdoor air’ has had everything but the CO2 washed out of it or destroyed by sunlight and oxygen. See their cleverness?
So, not a minor consideration, the effects of CO2 on human cognition. But something to put some thought into, because we haven’t even begun thinking about fixes or weighing alternatives. Also not a reason to take AGW seriously, another thing we haven’t started about thinking how to fix. One could speculate that converting to organic agriculture would add to the soil more carbon than we are emitting, as one line of thought. I have seen discussions of that idea, will link to the next paper I see.
Probably should hurry however. The effects might be nonlinear.
Added later : there is no indication of long-term effects. People endure 1200 ppm CO2 in conference rooms, and no doubt higher than that throughout history in buildings with smoky fires. The smoke is the killer, the perfumes and body odor is the reason for the poor air quality. CO2 will make you sleepy and slow, but Carbon Monoxide, CO, is the danger with the indoor fires. The danger is the pollution, not the accompanying CO2. It might not be good for us, but we handle it much better than the real pollutants, and it is much easier to reduce than the pollutants, generally. The above is an attempt to conflate the different problems.