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- Hacker News
- Of course, do it with vats of plant cells in floating oceanic CO2 factories. Not in your living room.
Or, just let the oceans recover, let the mollusks return to the bays and shores, let them do their efficient thing.
by JoeAltmaier - Related tangent: I recently bought an inexpensive consumer CO2 monitor for under $40. It confirmed my suspicion about air quality in my home office; after a few hours, levels rise above 1000ppm unless I leave a window partway open. Mid-afternoon mental fog cleared right up.by chrisweekly
- I find it especially a problem at night. Started out leaving the window open in the bedroom, but that lets in noise and wind. Current solution is leave the bedroom door open and have a window cracked open in another room. It seems to work out really well as measured by my CO2 monitor.
I mentioned this elsewhere here, but a friend told me that it’s not only CO2 that leads to that mental fog, but it’s also the VOCs in the air too. All that gets cleared out by having an open window.
by tito - What if the plants were algae?by moebrowne
- I did some of the napkin math on algae a couple years ago... The fun realization is that the physical carbon has to go somewhere. So if we're trying to sequester the average american's 14 tons a year of carbon or whatever it is these days, that means you're going to have at least 14 tons of dead algae to deal with. (And a lot more weight if the algae isn't dehydrated.). That's a lot of dead algae, which demonstrates the difficulty of the problem...
In other news, have you considered ditching your car and becoming a vegetarian? Not emitting the carbon in the first place is much easier!
by sdenton4 - Here's a real world* example:
https://www.youtube.com/watch?v=AAbyUaLN2QA
*youtuber
by alnwlsn - Or… you could go outside?
But the analysis rests on 0 ventilation, which doesn’t work at all.
I think the main thing to keep in mind is plants really aren’t industrial carbon sinks. They were never evolved to be. Their biological functions are about growing and thriving, and the soil they grow in are net carbon producers.
In a broad open system, they are net carbon sinks over the long term. But any analysis in a closed system is bound to fail, you don’t even need numbers to know intuitively this won’t work.
Crack open a window. Run a fan. Have plants because they have many benefits. Reducing CO2 around you meaningfully isn’t one of them.
- Outside it's not much better it's 430 ppm. Supposedly that's not enough to impact cognition.
- OK, this was fun.
But I think the real problem is that we’re pushing carbon into the atmosphere that has hitherto been sequestered for upwards of millions of years deep underground and under the oceans. I.e., nothing that’s been a part of a plant, or involved in any ecosystem, on the surface or underwater for a very long time.
Do we even have enough land on the planet to grow enough plants to sequester all this additional carbon? If we reforested the whole earth, would that be enough (and over what time period)? Can enough plants grow in the oceans without turning them all into a giant algal bloom?
I don’t know but I certainly would like to see the maths that answers those questions.
by bartread - The BBC did this in their 2012 documentary mini-series "How to Grow a Planet" with Iain Stewart. It was a lovely series; I highly recommend it.by ninefathom
- You can sequester carbon with plants, but you can't let them decay or it will release it back into the environment (it's called the "carbon cycle" of a reason).
A startup has solved this problem the following way (for example): grow microalgae near a very dry desert, and bury it in trenches. It never decays and thus never releases CO2 due to lack of water.
Basically, we'd have to permanently stick it back underground again.
by asdfman123 - To me, this is great that demonstrates how ridiculous carbon capture and storage is. I just can't imagine us paying to do something like this at scale, when we have a much more straightforward alternative: Stop burning fossil fuels, and use clean energy instead. Right? Like why even both going through the effort of carbon capture, when we're still going to have to stop burning fossil fuels anyways, in order to fix the climate?by gamegod
- You don't necessarily have to bury the plants to sequester the carbon. A lot of oceanic carbon just sinks to the bottom and is eventually covered over, especially near estuaries that spew silt.by t0mpr1c3
- I don't really understand this. First of all, you can just weigh the plant, and tell how much CO2 it has captured, right?
Second of all, what does it matter how much CO2 I produce? What's harmful is the additional CO2 that goes into the atmosphere for burning fossil fuels. All other CO2 is just in the same cycle that's been happening for ever.
EDIT: My child comment is dead and vouching doesn't resurrect it, but now the post makes sense, thanks for the clarification.
by stavros - > what does it matter how much CO2 I produce
Because the author of the piece is worried about the CO2 levels in their home, not about global warming. (well maybe they are worried about global warming too, but that's not what this is about)
by advisedwang - OK, so we can’t use plants.
What are the options, then?
In my apartment I’m running 2 AirGradients. One in the bedroom and one in the main room.
Awesome little devices, btw. They monitor temp, humidity, CO2, TVOC, and various particulate matter metrics. They expose prometheus metrics for scraping, and can be configured through a REST API to never phone home. I’ve got grafana alerts set up to push notifications to my phone when things get to “bad” ranges.
Anyway, the big issue is that the only way I’ve found to clear CO2 and TVOC is to open windows. However, windows open means increased humidity and particulate matter, even with air purifiers running aggressively. Also, opening windows at night kind of sucks for obvious reasons. In the summer it also sucks to lose that cool air.
I found these devices you put in your window, sort of like window fans, that can open/close airflow completely, but they don’t fit in my side-opening windows.
The only other thing I can think of is some kind of home automation with a little gadget that cracks the window until the metrics are back in an acceptable range. My AC unit unfortunately does not have a mode where it takes air from outside. I know some things like this exist for opening blinds, etc, but haven’t gone down that rabbit hole yet.
Anyone find a good way to solve this problem?
by prhn - If it wasn't an apartment and you could cut holes in the wall, I would say a ductless HRV.
- "Residential CO2 scrubber" seems like the sort of gadget eccentric rich people would buy, sort of a distributed DAC system.by frankus
- NASA is working on it: https://www.nasa.gov/spacecraft-oxygen-recovery-scor/by pstuart
- Challenging in an apartment setting, but the state of the art here is an Energy Recovery Ventilator (ERV) installed in your home to continuously refresh the air.
- (Author here) I've added the word "indoor" to the title, which will hopefully make it harder to miss that this is not about climate change or carbon sequestration.by dynm
- Did you consider the alternative calculation of how many plants you need to grow to feed yourself? A few thousand potatoes growing simultaneously might do it.
That would overestimate the number you need to remove excess exhaled CO2, since you could throw out the parts you can't eat rather than letting them decay and release CO2 indoors.
by penteract - It's an interesting article overall, but this assertion:
> Carbon dioxide is bad for cognition.
is dubious and unsupported by science. As I point out downthread, we have extensive experience with very high-CO2 environments-- at levels regularly exceeding ten or twenty times current atmospheric levels-- and as yet little good evidence of uncompensated cognitive effects.
Beyond that, modern humans live much of our lives in moderately elevated CO2 with no apparent ill effect. Without deliberate ventilation, any enclosed space like a bedroom or classroom will rapidly achieve elevated CO2 levels, often into the thousand ppm range. Again, we have lots of data, and little of it points to a practical cognitive effect.
The US Navy maintain an informal goal to keep levels on board submarines to below 8000 ppm, loosely informed by what little evidence they have of its effects on crew performance. That's twenty times the current atmospheric levels. In practice, CO2 levels often go over 10,000 ppm, which apparently still doesn't cause them much concern.
by nate_meurer - As somebody who works on carbon dioxide removal at planetary scale, I was excited about your article about indoor air… but nearly every comment here seems to want to talk about the changing climate!by tito
- Trees respire. They breath in and out. At night time, many trees emit more CO2.
And trees don't exist in isolation as these napkin calculation articles consider them (spherical cows and all that). Every single tree on earth relies on mycorrhizal fungi for the vast majority of its nutrients. Fungi break things down release CO2.
Most of our oxygen comes not from forest but from oceans (specifically from phytoplankton, algae, and photosynthetic bacteria). Between 50-80% of it in fact. Likewise, most of the CO2 that has been captured has been captured by the ocean not by forests. About 25-30% of all human emissions have been captured by the ocean.
Forests (and grasslands) are tremendously important for ecosystems and our health but I think this focus on CO2 and oxygen is simply misleading. If that's your concern you should really be focusing on the ocean. Which IMO is in an even more dire strait than our forests
by culi - “I couldn’t live with so many trees. They suck up all the oxygen.”by teddyh
- If the ocean is the main hero there, why is the forest still important to our health?by feelamee
- > Which IMO is in an even more dire strait than our forests
I think you are probably right, but could you kindly elaborate and provide more details? Very curious to hear your view and learn more.
- it looks like i'm guilty of having never really thought and done some research about this and i'm a bit ashamed to admit i fell in this trap and used to think forests and trees are the most important pieces in the system.
I don't get why media has been fixating so much on trees and forests (Amazonia!) without even mentioning ocean's role in this.
by guybedo - Forests and grasslands are critical for the climate because of the carbon they lock away. So long as the plants stay alive, they store carbon in the cellulose structures of roots and stems.
Conserving these ecosystems is less about their daily respiration and more about keeping existing carbon out of the atmosphere. It's a defensive strategy. Not "carbon capture" per se but more "avoid loosing the carbon we've already captured". We're interested in the sink, not the flow.
Of course when the plant dies and decomposes or burns up, it all goes back. Long term, it's almost exactly net zero. The ONLY way to use plants for long term carbon sequestration is to make sure that plant matter gets treated or literally buried so that aerobic microbes and fungi can't break it down.
by perrygeo