So you want to use plants to reduce CO₂

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• Hacker News
• 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.

  by randomImmigrant
• 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
• 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
• 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
• (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
• 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