So you want to use plants to reduce CO₂

2 hours ago (dynomight.net)

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

  • The ocean breathes in and out too. Very little carbon sinks down to the sea floor. The ocean does happen to absorb a lot of CO2, but that's from acidification rather than photosynthesis.

  • > 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.

    That fact checks out: about 70% of the earth's surface is covered by oceans. It follows that most photosynthesis, thus oxygen comes from oceans.

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.

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.

How is it that 132.5 watts is 3 light bulbs but 918 watts is 765 light bulbs? Is there a typo?

  • It might not be clearly worded, but 132.5 watts is the power used by 2 incandescent light bulbs, whereas 918 watts is the power present in the light produced by 765 light bulbs. The factor of 50 comes from the fact that incandescent lightbulbs are only ~2% efficient at turning power into light.

That one final number is all one needs as a reply for "but they help a little".

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.

  • > 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)

> Real plants do photosynthesis through a physical process

(nit) it is more accurate to call this a biological process, or chemical process

Saying "physical process" makes me think of inclined planes, free-body diagrams, and EM fields.

  • It's all physics at the bottom. Nature doesn't have APIs.

    • Yes, except parent is correct. Physcial and chemical mean very different and specific things in this context.

      Calling photosynthesis a physical reaction is flatly incorrect no matter how you want to look at it. It is a physics reaction, sure, but "physical reaction" specifically means a Newtonian mechanical, reversible process at the macro scale.

      A "chemical reaction" specifically means a (trivially) irreversible quantum/atomic reaction involving chemical bonds at the atomic/molecular scale.

no, we are useing solar PV to eliminate the excess carbon bieng added to the atmosphere, and plants, rocks, and many other natural processes will return CO² levels to a more moderate level.

  • Article is not about global atmospheric or climate phenomena, nor civilization scale industrial processes. It's about the CO^2 levels in your room due to your breathing.

    • oh no!

      realy?

      but since I live in a drafty farmhouse up on a windy hill beside the ocean, my room air and the atmosphere as whole have very similar compositions, and I will continue to treat conversations about both, the same as well.

  • Getting CO2 back to preindustrial levels by natural processes may take 100,000 years, IIRC. There will be some drawdown, but the ocean surface waters will become more saturated with carbon and that will stall. Over a longer time scale, CO2 will be pumped down into the deeper ocean. The true drawdown will require mineralization and precipitation as calcium carbonate, a slow process. The fossil fuel CO2 emitted each year corresponds to the calcium added to the ocean by erosion over about 100 years.

This seems trivial: if you could add enough plants to your room to reduce CO2, we could easily do the same thing at planet-scale and global warming wouldn't be an issue.