11 ms·
CO2 helps viruses stay alive longer in the air
- blueflow 2y ago> In its call to action, the group proposed CO2 as one of three key metrics, suggesting ventilation rates that would keep CO2 levels at 800 parts per million or below. Pre-industrial CO2 levels were at 280ppm, currently we have 420ppm, rising & accelerating. Give it three or four decades and ventilation won't help anymore. Edit: 420, not 480ppm
- SoftTalker 2y agoHouseplants. Lots of houseplants. More seriously, a house air filter with CO2 scrubber is not really something that would be difficult to make.
- J_Shelby_J 2y agoI would love that, but how? There is no available residential CO2 scrubbers.
- jefftk 2y agoBringing in external air (and filtering it, if it's polluted) will be way cheaper than scrubbing CO2 at current levels.
- unholythree 2y agoDefinitely. Filtering particulates and tempering the outside air is the way to go in anything but most extreme situations. I suspect even designing a fallout shelter you would want to go that route.
- dzhiurgis 2y agoAn ERV costs about ~$1000 plus labour (you can install yourself).
- somenameforme 2y agoThis is true, but mostly because the cost of bring in external air is near $0 in most cases - just open a few windows! But there's a lot of absurdly cool ways to scrub CO2 that are not especially expensive, like the video-game level of serendipity+convenience that's the Sabatier Reaction [1]. Combine hydrogen + CO2 at 300C => methane + water. It's already being used on the ISS to keep the air fresh. It'll also be a key component on Mars. There you have basically unlimited CO2 and unlimited hydrogen which yields unlimited methane and unlimited water. Carry out electrolysis on some of the water and you get hydrogen + oxygen. The hydrogen can be fed back into the original cycle, and so you end up left with methane + oxygen which is also known as rocket fuel, uncoincidentally the exact sort SpaceX's Starship is using. Back on Earth you could use this reaction to create practically endless carbon neutral fuel so long as the CO2 was sourced from either the air or a regrown natural capture source like trees or what not. Rockets using this fuel would even have a negative carbon footprint since some of that fuel will get burnt outside the atmosphere. It all seriously feels like a video game where there's just this perfect, but just utterly contrived, rule allowing you to thrive on the next level of difficulty. [1] - https://en.wikipedia.org/wiki/Sabatier_reaction https://en.wikipedia.org/wiki/Sabatier_reaction
- OutOfHere 2y agoThe reaction is most interesting, but there are three concerns: (1) It presumably requires concentrated CO2. It's not trivial to concentrate CO2 from the air without the appropriate technology. (2) Pure hydrogen can risk an explosion. (3) What does one do with the methane? Also, it too can risk a fire. For these reasons, this is not a reaction that one would seek to do at home.
- somenameforme 2y agoThe Sabatier reaction is completely safe. Here [1] is a video of a few kids doing it completely manually with a couple of syringes, a pipe, and a torch. Producing methane is one of the huge benefits. Methane is just a normal fuel - use it to generate electricity, for your oven/stove, heating, whatever. But at home if all you want is CO2 removal then just use some lye, soda lime, or a million other simple capture technologies. Not quite as sexy, but it'll get the job done. <rant> There's no grand technologies required for any of these things. The only reason it's not done at scale is the same reason we can't have nice things in general. Governments are far more interested in war and cock measuring contests than actually solving problems. We spent literally trillions of dollars on Iraq and Afghanistan, and the latest wars will probably dwarf that. Just imagine all the crazy sci-fi scale of things we could have done with all that money. Alas, humanity seems to be running on loop, except now we have nukes, paired alongside what are likely some of the most idiotic 'leaders' in centuries. Want to know the answer to the Fermi Paradox? </rant> [1] - https://www.youtube.com/watch?v=VdNPkW9I0fQ https://www.youtube.com/watch?v=VdNPkW9I0fQ
- autoexec 2y agoDon't the activated carbon prefilters used in many residential air filters work to scrub CO2 at least a little?
- alexey-salmin 2y agoTry calculating how much heavier the filter must become every day to make a difference
- TylerE 2y agoNot in the slightest. Those are for filtering volatile organics.
- Filligree 2y agoThere will be. Mind you, I’m not too happy about a future in which nobody can go outside.
- IncreasePosts 2y agoInstead of scrubbing CO2, just adding the other important components like N2 & O2 to reduce the percent of CO2 in the air would probably be easier
- EVa5I7bHFq9mnYK 2y agoNo, because CO2 is only 0.04% of the air, O2 is 21% and N2 is 78%.
- hollerith 2y agoNavies have been removing CO2 from submarines for decades. I think they use sodium hydroxide. Manned space programs must remove CO2 air breathed by astronauts. They used lithium hydroxide for decades (including famously in Apollo 13) but ISTR the international space station has a more sophisticated process.
- gpm 2y agoThe ISS has a clever trick of using zeolite beds to absorb CO2 (a rock with pores that selectively hold onto CO2, and H2O but they dry the air first), and then venting it to space to get rid of the CO2 and recharge them.
- johnsimer 2y agoIIRC you need ~300 plants to offset every one human in a house
- jefftk 2y agoYes, it's impractically high: we exhale about 1kg of carbon daily, so your plants collectively need to be getting about 1kg heavier daily to absorb that.
- CGamesPlay 2y agoDon’t the plants exhale oxygen? So they won’t be getting 1kg heavier, closer to 300g, but I don’t know the actual chemistry.
- alexey-salmin 2y agoThat's just dry mass and plants are mostly water.
- SoftTalker 2y agoYeah it was sort of a joke, but having houseplants will make some difference. Not that they would be practical to absorb all the CO2 in the air. On the downside, keeping indoor plants healthy does take some ongoing time and effort and isn't everyone's cup of tea.
- alexey-salmin 2y agoIt often makes a negative difference because bacteria in the soil produce a lot of co2.
- alexey-salmin 2y agoIt's an order of magnitude worse than that, plants are mostly water, not carbon. They'll gain tens of kilos per day. If you can feed off your house plants alone, then you have a chance of closing the carbon loop. This was tried (e.g. biosphere2) and it's extremely hard even at the industrial scale.
- IvyMike 2y agoWhen plants remove CO2 and release O2, they have to do something with that carbon atom. They can use it to make sap or fruit, but mostly they use it to build more plant. A plant that isn't growing, like, a LOT, can't possibly be removing much CO2.
- BurningFrog 2y agoMost of a tree is CO₂ that the plant has taken out of thin air. This only clicked for me when I started wondering why you never have to refill the soil for a houseplant even when it grows.
- teh_infallible 2y agoRichard Feynman talked about this in his talk about “What is Fire?” https://www.youtube.com/watch?v=N1pIYI5JQLE https://www.youtube.com/watch?v=N1pIYI5JQLE
- somenameforme 2y agoThe soil itself is also storing CO2, in a variety of different less than intuitive processes. The most obvious is when parts of the plant die and breakdown into the soil itself.
- elevation 2y ago> currently we have 480ppm Where are you measuring 480? [0] says the recent global average is 419.3. [0] https://www.climate.gov/news-features/understanding-climate/climate-change-atmospheric-carbon-dioxide https://www.climate.gov/news-features/understanding-climate/...
- coldtea 2y agoDoes the global average count where most people live, or does it average New York and Mexico City with rural Idaho and Bretagne?
- mike_hearn 2y agoBelieve it or not the standard is to report the CO2 level measured at the top of an active volcano (Mauna Loa). This is for historical reasons, because it's where the first measurements were taken, but also they claim it's more accurate because the measurement site is surrounded by miles of lava and thus there's no trees or vegetation which could absorb CO2 locally nor any human settlements that could emit CO2. There is of course the small problem of it being a volcano. Other measurements come from a collection of sensors on TV or telecom towers. Some of them come from planes. You can see a map of sites here: https://gml.noaa.gov/dv/iadv/index.php?code=sgi https://gml.noaa.gov/dv/iadv/index.php?code=sgi The trend is the same in every site, although absolute readings vary somewhat. There are cleaner sites than Mauna Loa, like in Antarctica, but those show about 10ppm lower. Others give the same reading as at Mauna Loa but with more seasonal variance. It's unclear whether these differences really matter and they tend to be ignored.
- cozzyd 2y agoI have two vials of "the world's cleanest air" from the south pole NOAA observatory
- blueflow 2y agoI probably read 420 somewhere and misremembered.
- 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.
- robxorb 2y agoHow did we measure CO2 accurately pre-industry? Isn't the rise of industry kind of coincident with the ability to measure gases accurately? And if the trend as accuracy increased was up, wouldn't it suggest initial underestimates? Or is there some reliable way we can measure in retrospect?
- leptons 2y agoSometimes air gets trapped in unusual places. When these types of things are found, that air can be tested with modern equipment. "Ancient air pockets changing the history of Earth’s oxygen" https://www.sciencedaily.com/releases/2016/08/160822174234.htm https://www.sciencedaily.com/releases/2016/08/160822174234.h...
- robxorb 2y agoThanks, though that study makes no mention of CO2, and concerns instead oxygen from 500m, to 1b years ago, which seems a little far off to be applicable to the order of the around one hundred and fifty years ago being asked about. Have I missed something?
- leptons 2y agoMy comment only explains how it's done. I'm sure you can understand that the article I mentioned was just an example. If you're looking for a specific CO2 measurement from air captured exactly one hundred and fifty years ago, I'll leave you to Google that yourself.
- robxorb 2y agoWell, here's the only solid thing with referenced figures that came up. Chart on page one is quite the ride, as I'd have expected for early science: https://21sci-tech.com/Subscriptions/Spring%202008%20ONLINE/CO2_chemical.pdf https://21sci-tech.com/Subscriptions/Spring%202008%20ONLINE/... Everything else I found was unfortunately hand-wavy "scientific consensus says" and the ubiquitous "280ppm" coupled with "pre-industrial" repeated again without reference, nor apparent empirical basis. Not convincing, which for "the science is settled" I'd expect a bit of a higher standard.
- gpm 2y agoCO2 levels are increasing at ~3ppm/year*. In 40 years we're looking at roughly 120ppm. Noticeable but not "we're all going to have headaches and covid" numbers. I mean we might all have headaches and covid, but not directly because of CO2 at outdoor concentrations. * 2.8ppm in 2022-2023, the rate at which CO2 is increasing is very slowly increasing but it's close enough to constant for rough calculations, especially after rounding up to 3.
- genman 2y agoThe rate is increasing, it is not constant. It used to be 1ppm per year. So it will be not 120ppm extra, it will be more. It might appear not much but when you consider indoor air then when currently room stayed below the recommended CO2 limit, it maybe now be above of it or you need more air changes that will require more energy (to move air and to condition it). And while 120ppm in 40 years might appear not a lot then you should also consider that 40 years is actually very short time - in 120 years it will be about twice as today - there would be no fresh air anymore.
- aeternum 2y agoEarth CO2 concentrations during the Triassic were 6000ppm.
- seadan83 2y agoPerhaps not that high. Regardless, entering that period was marked by a mass extinction.* This source [0] states it well: "The end-Permian mass extinction, the largest biological crisis in Earth history, is currently understood in the context of Siberian Traps volcanism introducing large quantities of greenhouse gases to the atmosphere, culminating in the Early Triassic hothouse. In our study, the late Permian and Early Triassic atmospheric CO2 history was reconstructed by applying the paleosol pCO2 barometer. Atmospheric pCO2 shows an approximate 4× increase from mean concentrations of 412–919 ppmv in the late Permian (Changhsingian) to maximum levels between 2181 and 2610 ppmv in the Early Triassic (late Griesbachian)." [0] https://pubs.geoscienceworld.org/gsa/geology/article/50/6/650/612995/Five-million-years-of-high-atmospheric-CO2-in-the https://pubs.geoscienceworld.org/gsa/geology/article/50/6/65... * looks like we can quibble on 2k ppm or 5k ppm, the salient part is the global mass extinction part. Whether that was a correlation or caused by CO2 is not defined, at any rate it is not really speaking to a very habitable earth for humans.
- s0rce 2y agoTitle seems misleading. It seems that they have results that elevated levels of CO2 in the air increase survivability of viral aerosol particles and infectiousness. Since CO2 is so low (400-1000ppm) this is surprising. Haven't had time to look through the paper closely but seems to be pH related which makes sense. https://www.nature.com/articles/s41467-024-47777-5 https://www.nature.com/articles/s41467-024-47777-5
- dang 2y agoWe've replaced the page title with the HTML doc title now. is that better?
- bilsbie 2y agoFound the critical thinker.
- glitchc 2y agoIf the concentration is so low, would the pH change appreciably? Air is not a liquid after all.
- gpm 2y agoAir isn't a liquid, but the virus is contained within a tiny bubble of water as I understand it. Atmospheric CO2 change acidifying the oceans is a well known effect [1]. Once it's pointed out it isn't surprising that a tiny bubble of water surrounded by atmosphere would change PH quickly in response to atmospheric CO2 levels (the surface area to volume ratio is huge compared to the ocean after all). Nor that that affects viruses. [1] https://www.noaa.gov/education/resource-collections/ocean-coasts/ocean-acidification https://www.noaa.gov/education/resource-collections/ocean-co...
- glitchc 2y agoAh that makes sense. Thanks for the explanation.
- s0rce 2y ago
- SwellJoe 2y agoHow is that new information "challenging old ventilation doctrine"? It confirms old ventilation doctrine: monitoring CO2 remains a good proxy for general air quality, including viral and bacterial threats, and reducing CO2 via ventilation reduces other threats. That's doctrine, and now it has stronger evidence to support it, and another possible explanation for why and how well CO2 is correlated with other air quality issues. Ventilation good. CO2 bad. No challenge to old ventilation doctrine detected. (The article and the research seems much more nuanced than the silly title.)
- itronitron 2y agoI think it's challenging the old ventilation doctrine which was that the people who wanted fresh air were just neurotic hypochondriacs.
- miraculixx 2y ago[flagged]
- jefftk 2y agoThe old doctrine was that CO2 was a proxy for air quality, and the (somewhat overblown title) is about seeing CO2 additionally as having a causal effect. For example, under the "proxy" model, if you're worried about infection risk it's sufficient to filter the air, but under the new model filtering will work less well than you'd expect because the viruses you miss will stay active longer.
- SwellJoe 2y ago"The old doctrine was that CO2 was a proxy for air quality" That's not accurate, though. CO2 is, on its own, an air quality concern. It has also been known, or at least part of the conversation, since Florence Nightingale's time, that fresh air reduces infections (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9300299/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9300299/). This research makes a small tweak to our understanding, but it's also something that's been suspected/suggested by others for decades. This research isn't "challenging" anything, it's merely expanding our understanding of causation about previously observed correlations. It's good to know what's happening. It's silly to make it out to be something it's not.
- andrewflnr 2y agoEven if the title is silly, the article is well worth reading IMO.
- deleted 2y ago[deleted]
- dilippkumar 2y agoTangential, but I've had this monitor[0] at home for about 2 years and I can recommend it. I live in a place that's generally cold for a large part of the year, so I have all windows shut for most of the time. I've discovered that tracking CO_2 levels is a very good proxy for general air quality, and a good measure of both when to open windows and for how long to keep windows open. For my apartment, I was surprised that the amount of time I needed to keep the windows open was 5x longer than what I initially assumed (I assumed 5 mins would be enough. Data shows that I need about 25 mins to get CO2 levels down to around 500ppm). I was also surprised to see how much more rapidly CO2 builds up when I have just 2 additional people at home. [0] https://www.airthings.com/view-plus https://www.airthings.com/view-plus
- victor106 2y agoHow accurate is this?
- deleted 2y ago[deleted]
- dilippkumar 2y agoI don't have any equipment to calibrate it or measure it's calibration against. However, when I leave the windows open for extended periods of time, the CO2 levels hit levels that are within 50ppm of [0]. (I live in a different city from this station, with different population density, traffic patterns and all sorts of other micro-climate stuff that can contribute to a baseline difference. Additionally, CO2 levels swing by several hundred ppm when the air quality goes bad, and the ~50ppm range is insignificant in comparison) It seems good enough for how I use it. I wouldn't conduct chemistry experiments using this as an instrument. [0] https://gml.noaa.gov/ccgg/trends/monthly.html https://gml.noaa.gov/ccgg/trends/monthly.html
- EVa5I7bHFq9mnYK 2y agoAll these devices calibrate by periodically measuring the lowest ppm in a given period, and assigning it a value of 420. That's how they always accurately measure CO2 with the windows open.
- fwungy 2y agoI bought a cheap AQ monitor off Amazon that does CO2. Anecdotally, I feel better when CO2 is lower. It's definitely sold me on the value of fresh air.
- verisimi 2y ago[flagged]
- seadan83 2y agoIt's pertinent to indoor air quality and interpreting an indoor C02 reading, specifically per its implications of indoor air quality and the ability of virus to survive at that lowered quality.
- ldehaan 2y ago[dead]
- sharpshadow 2y agoInteresting, maybe because of less oxidation.
- chipsdip 2y agoViruses are non-living. They are not organisms and cannot be "alive".
- OutOfHere 2y agoEvery organism is alive only in a certain medium. Viruses "come alive" in a host, e.g. a human body, or in solution. Humans are live only in Earth's environment. There is no life without the context of the broader environment that it can live in.
- chipsdip 2y agoA virus is a pathogen, not an organism
- quercusa 2y agoMain takeaway: That extra CO2 acted like a buffer keeping the particles closer to a neutral pH, where respiratory viruses are quite content.
- ThomPete 2y agolol yes and thats a good thing
- aaron695 2y ago[dead]
- OutOfHere 2y agoHere is an excellent CO2 meter if you seek one for home or office use: https://www.amazon.com/gp/product/B01FYWU2IS/ https://www.amazon.com/gp/product/B01FYWU2IS/ I can vouch for the monotonic rise or fall in its displayed values as affected by ventilation.