3 ms·
> Pre-industrial CO2 levels were at 280ppm, currently we have 480ppm, rising & accelerating. Give it three or four decades and ventilation won't help anymore J
by logifail 2y ago
> Pre-industrial CO2 levels were at 280ppm, currently we have 480ppm, rising & accelerating. Give it three or four decades and ventilation won't help anymore
Just to add a little context, here's a table from https://www.dhs.wisconsin.gov/chemical/carbondioxide.htm https://www.dhs.wisconsin.gov/chemical/carbondioxide.htm
400 ppm: average outdoor air level.
400–1,000 ppm: typical level found in occupied spaces with good air exchange.
1,000–2,000 ppm: level associated with complaints of drowsiness and poor air.
2,000–5,000 ppm: level associated with headaches, sleepiness, and stagnant, stale, stuffy air. Poor concentration, loss of attention, increased heart rate and slight nausea may also be present.
5,000 ppm: this indicates unusual air conditions where high levels of other gases could also be present. Toxicity or oxygen deprivation could occur. This is the permissible exposure limit for daily workplace exposures.
40,000 ppm: this level is immediately harmful due to oxygen deprivation.
- IvyMike 2y agoThe outlier to this the US Navy's experiments. Discussion on an older HN thread: https://news.ycombinator.com/item?id=19863319 https://news.ycombinator.com/item?id=19863319
- taeric 2y agoThanks for linking that! Will be hunting a bit for any recent takes on these studies. I'm finding I can't really tell any difference in mood/alertness/whatever despite what my sensor thing reports. To the point that I don't know why I bother keeping this thing in the office.
- dzhiurgis 2y agoSame here, but I do love fresh air in my home.
- taeric 2y agoIt is only in my office that the values get high. Rest of the house is fine. My suspicion is these devices just can't really tell you much about how localized the readings are. And comparing a number for a large room to a converted closet is not at all meaningful.
- dzhiurgis 2y agoOur bedroom with windows shut and ventilation off gets stuffy within an hour. Minutes if you are doing the deed.
- OutOfHere 2y agoThose levels are absurd. The optimal level is the pre-industrial level of under 300 ppm which is what humans evolved under for millennia. The levels outdoors are closer to 500 now than to 400. Drowsiness starts at levels as low as 600-800.
- Ferret7446 2y agoCO2 is "self modulating". Photosynthesizing species become more productive and lower it. Tangentially, too much O2 is even more dangerous (as O2 is extremely reactive unlike CO2), but it too is "self modulating".
- seadan83 2y agoPlant photosynthesis has its upper limits. So, self modulating to an extent. I think the article is more insightful around I indoor air quality rather than outdoor. With respect to outdoor, if CO2 were fully self modulating, isn't the fact it has been consistently raising a counter point to that idea? How does self modulation explain the data showing increases?
- OutOfHere 2y agoDo you believe in the flat earth too? CO2 has risen in front of my eyes in my lifetime from 350 to 420. It most certainly is not self-modulating. Oxygen isn't either, as it slowly escapes into space.