Accelerating Photosynthesis
rubyplants.com
rubyplants.com
The resulting O2 actually comes from a pair of H2O.
Consider the reaction performed by purple sulfur bacteria, which are related by evolution but have a slightly different reaction. It is this:
CO2 + 2 H2S gives [CH2O] + H2O + 2 S
There, carbon dioxide reacts with hydrogen sulfide to give water, sulfur, and part of a carbohydrate.
Photosynthesis in plants is the same sort of reaction, but the situation is less obvious because there is H2O on both sides of the reaction. We've proven what happens by experiments with radioisotopes.
The entire photosynthesis reaction consumes 6 CO2 and 12 H2O to produce 6 H2O, 6 O2, and a sugar.
From the 12 H2O, half of the H goes to the sugar and the other half goes to producing new H2O.
From the 12 H2O, all of the O goes to producing O2.
From the 6 CO2, half of the O goes to the sugar and the other half goes to producing new H2O.
From the 6 CO2, all of the C goes to producing sugar.
You know the cliché that something designed by evolution, or "natural", is usually pretty efficient, sort-of "in sync" with its surroundings, etc. For many things this subjectively holds true, with things like Spider silk, flight of large birds, a diving penguin, etc.
Photosynthesis, and the core protein, Rubisco, is anything but! It's the central protein of live on earth, and yet... it's a totally ridiculous machine.
You ever wonder what the inside of a typical cell sounds? In a cartoon it would be a high-pitched whining, because that correlates well with the typical speed at which some protein does its business when busy.
Rubisco is the fat guy lazily picking up the hammer every once in a while, balancing it in the air, slamming it down and...missing 2/3 the time.
So this idea does have potential. Unfortunately, the plant biophysics have been well understood for a few decades, and the idea isn't new or anything.
I'd say the even-odds of doubling the CO_2 fixation of some plant we can grow on a large scale is about 20%.
It is completely irresponsible to let this, and other such schemes, inform policy wrt climate change right now. Invest in research, yes. But using it to put of necessary changes is just motivated reasoning an will end with nothern russia looking like Florida, and Florida looking like what's 30km east of Florida now.
However, the IPCC (UN group in charge of research for climate change) does predict an increase of ~0.2 to 0.5m (basically a foot) of the sea level in the next century.
Here is the source for interested people : https://archive.ipcc.ch/publications_and_data/ar4/wg1/en/faq...
So when photosynthesis is "inefficient" after billions years of evolution, surely we would be more careful with the conclusions.
"Photosynthesis is only 1% efficient" sounds a bit like "we only use 10% of our brain" (according to some measurement).
> Photorespiration wastes little energy and instead enhances nitrate assimilation, the process that converts nitrate from the soil into protein, according to a new study.
> Most plants, contrary to popular belief, do not waste over 30% of their photosynthate in a futile cycle called photorespiration. Rather, the photorespiratory pathway generates additional malate in the chloroplast that empowers many energy-intensive chemical reactions, such as those involved in nitrate assimilation. Thus, the balance between carbon fixation and photorespiration determines the plant carbon–nitrogen balance and protein concentrations.
There is also likely to be huge opposition to injecting GMO plants into the biosphere. I make no judgement on this, just highlighting the issue.
(obviously I mean from the perspective of a plant that wants to grow faster, what matters from a global perspective can and probably will be different)
e.g. https://www.forbes.com/sites/jamestaylor/2012/10/25/contrary...
Grass puts Nitrogen into the soil. There are other plants, but grass is the most well-known. Things like corn or grain take nitrogen out, and use it. In nature these plants grow centimeters apart, so there is no problem. There's a nitrogen cycle. However if you want much denser grain, you can only have grain.
So now we've got agriculture, and it requires density. Large plots of land where you've got nothing but grain. Nitrogen goes out, doesn't come back in. Grain grows for 2-3 years, then refuses. It dies, because it cannot use the nitrogen from the atmosphere. It can only get it from the soil.
So we found a solution a very long time ago (it's in the bible, surprisingly, although we have figured out slight improvements since then). Do agriculture in a 7 year cycle: leave blank, grain, grass + animals, grain, grass, grain, grass + animals. There are many cycles used in various places, but they're all quite similar.
Fertilizer shortcuts the process: so why does it increase the yield 3 times ? Because you can cut out the grass years and the blank years. Not because the plants grow faster, because you can grow 3x as many of them.
This is against current consensus. The consensus is that plants do grow faster when you put fertilizer in the soil and the yield increase is because of that, not because of the "grass years".
There are plenty of studies on this, one example:
> Crop yields were increased by 19–41% (rice) and 61–76% (rapeseed) during the two years of rice-rapeseed rotation under NPK fertilization compared to PK fertilization across the study sites. Yield responses to fertilization were ranked NPK > NP > NK > PK, illustrating that N deficiency was the most limiting condition in a rice-rapeseed rotation, followed by P and K deficiencies.
https://www.nature.com/articles/s41598-017-01412-0
Anyway, you are making my point. Notice how you say that crop rotation, soil quality are extremely important. So much for CO2.
All of water, CO2, and nitrogen (not an exclusive list) can stunt growth, and increasing the levels of any one of them can accelerate it.
Your own link points to this, referring as it does to the "most limiting condition", and the fact that addressing P and K deficiencies also increases yield, but not as much as also addressing deficiencies in N.
Nitrogen deficiency is the factor that would promote the most growth, but at the same time, it's fair to think of all plants as constantly CO2 starved.
We would be pretty miserable at 800ppm CO2, but plants would love it.
This sounds like the typical junior developer starting working on a 20 years old project saying 'Wait a minute, I can rewrite these 50k lines in 500 lines of _insert tech of the day_' while ignoring 20 years of side effects, special cases, well thought decisions, &c.
That would be so far in the future though we can't even imagine what the earth would be like, or what we would be capable of, or what the population would be. Hopefully we decided it was important to leave large natural spaces on the planet.
Unfortunately, evolution doesn’t do balance, but rather local gradient descent. Species reliant on one prey or one plant can and do over-consume their food into extinction and then go extinct themselves. Even the oxygen we breathe was a toxic waste product when the earth was young, and while evolution found a pathway to consuming it, there’s never any guarantee of that.
Evolution has had a long time to find solutions, so it shouldn’t be ignored, but it’s also not a particularly smart system and it definitely isn’t directed with long-term goals in mind — evolution can create birds, but not birds which grow their own hypersonic ramjets.
To me, this implies some other limiting factor that we don't understand.
I expect us to find out why evolution didn’t do it by doing it to the plant genome ourselves — and that either it requires too many simultaneous changes for evolution, and/or it turns the plant into something irresistible to insects or fungi.
If something requires, say, five individually-deleterious mutations, each of low probability, it's quite plausible that these will never align in a single organism.
There may be a more esoteric explanation... Imagine higher efficiency has a price : plant lives a shorter life, and reproduces less. Then you want to fine tune for the right amount of efficiency in your environment. Then it's advantageous to have a single efficiency lever, instead of a dozen systems to fine tune jointly... Just a guess - I know nothing about bio. :)
FWIW I'm quite bullish on the type of research in the Fine Article; humans have the ability to provide choice conditions to our crops, and so we can maximize yield without (much) concern for the tradeoffs experienced in the state of nature.
I'd predict, for example, that we'll have a C4 rice crop out of the lab and in the field in ten years or less.
Global warming is changing the rate of how fast local habitats change and therefore NO ANIMAL ON THIS PLANET is likely going to be able to handle the rate of change. Which is why we are in the 6th mass extinction.
In other words, animal life is locally calibrated, not globally and if you change the global system (therefore changing every local system quickly) you will get a bad bad situation.
> NO ANIMAL ON THIS PLANET
My guess is that cockroach will be fine. Perhaps no all species of cockroach.
Some animals have a wide distribution. Sparrows live in a wide range of climate, they have different size (in cold climates, they are bigger). Many birds migrate, some of them can probably change the extremes of the migration path and be fine.
I'm more worried for elephants and other animals with a long lifespan and small area where they can survive. (And I'm more worried about trees, because they can't move.)
> Species reliant on one prey or one plant can and do over-consume their food into extinction and then go extinct themselves.
Well, of course, I didn't say nature was immutable, just self balancing. I doubt you can deny that life as we know it is heavily reliant on plants and that doubling or halving plant photosynthesis efficiency would have consequences we simply cannot predict. When simple things such as reintroducing wolves in a park can unexpectedly change the course of rivers [0] I'm really wary of people wanting to "improve" the world by shaping it in such extreme ways and promising the results to be 100% beneficial.
[0] https://wilderness-society.org/wolves-change-flow-of-rivers/
And that, specifically, is what I’m denying.
Think of it another way: humans are a product of natural selection, so every imbalance we cause to the environment is an example of evolution not being balanced.
Not balanced ? You should look into global co2 level, how it's linked to cognitive performance, climate change, &c. The balance is about to smack us right in the face if you ask me.
And if you want to make that argument, you’re now arguing my point for me ;)
(My stance is that that doesn’t count as balanced. We can still figure out how to drive faster than the fastest land mammal).
Sure, that's how we got one of the most polluting industry of the last 100 years, see, all balanced. We took one thing, transport, and made it a priority while ignoring every other aspect, and now we're all breathing polluted air.
Roads are bendy because they follow the topography of the terrain, cars aren't faster because we'll still get fucked by drag no matter how smart we'll get https://i.stack.imgur.com/PKkDf.jpg but we're getting off topic.
Most of the oxygen is produced by cyanobacteria in the sea (not by trees as is a common misconception). These morons have already once produced so much oxygen that killed most life. https://en.wikipedia.org/wiki/Great_Oxidation_Event
If they could do it again because they discover how to make a more efficient photosynthesis, they would do it without hesitation.
Another common example is electric heat versus geothermal heat pumps. Electric heat is "100% efficient" in the sense that essentially all the electric energy is converted into heat. And yet, a GHP can provide the same amount of heating using less electric energy, because it's moving heat from an effectively free and unlimited source.
You say that like that’s inherently a bad thing.
IIRC (from some other commentor’s previous napkin math), such a change would actually be unlocking a lot more livable/arable land than would be desertified by it. Just counting the tundras in Northern Canada + Northern Russia + Antarctica + Greenland, that’s already more potential arable/livable landmass than the entirety of the US + Europe.
What you should probably highlight, if you want to make an argument like this, is the time scale. If that change occurred over ~100,000 years, it’d probably be a great thing for human civilization, and, though it’d kill off a fair number of animal species, there’d also be time for many new adaptations to occur, so overall biosphere diversity wouldn’t be greatly impacted. The Earth would be different, but not necessarily worse.
It’s the fact that said change has the potential to occur over only ~100 years, that screws the biosphere (including us) over.
That's fine if you want to spend trillions moving the cities of Europe and US to Siberia.
It would be much cheaper, and require far less political co-ordination, to avert the CO2 emissions leading to climate change in the first place.
And even if you do take the incredibly drastic step of moving most of humanity to the Arctic circle, you still have the problem of runaway heating. What are you going to do when the climate changes for the places you have moved to?
Besides, I rather like having a range of different biomes available on my planet.
> That's fine if you want to spend trillions moving the cities of Europe and US to Siberia.
I don't even want to get into thinking why and if Russia [1] would let the people of Europe and the USA in, but that's only about 1 B people. There are many more out there.
[1] The Nordic countries and Canada, and probably the south of Chile and especially Argentina, are similarly well positioned.
The ideas in there are quite interesting to think about. I'm glad I read it, but questions like this are unsettling given the lack of expressed ownership:
"Why bother with environmental control and especially environmental optimization when the goal is accelerating photosynthesis genomically?"
[1] https://www.sublimesucculents.com/plant-for-thought-online-n...
If they're getting more serious, though, I think they might be better served by an editor's rewrite of their 15 pages of Khan Academy-like scribbled slides.
For instance, I would imagine that competition in the Amazon amongst plants is high enough to have driven a photosynthesis efficiency arms race. Do different plants differ significantly in their photosynthesis efficiency? If so I would study the genomes of plants in the Amazon, or similarly competitive environments.
C3 plants hit optimal levels at higher concentrations, usually 1100-1300 ppm (90% of plants fit this category). See link below for more details:
https://rclutz.wordpress.com/2020/01/08/heres-looking-at-you...
Now I don't know how the mechanics work. I don't know if you could genetically engineer a C3 plant to work as well as a C4 plant. I reckon there are significant tradeoffs there that nature already factored for.
The article also mentions RuBisCO being partially synthesized from chloroplast DNA, which limits evolutionary speed.
Nature does evolve improvements (e.g. better rubisco in microorganisms, the C4 pathway in some higher plants) but other plants can't just download the updates from a central DNA package library.
It could very well be that more efficient photosynthesis is actually detrimental.
Making everything faster/stronger/lighter at all cost is a human thing, nature is about balancing thousands of variables, not optimising the shit out of a single aspect while ignoring the rest.
[1] https://www.sciencedaily.com/releases/2018/03/180301094857.h...
There's a map at the bottom of http://rubyplants.com/autonomous-chambers-2.html
Seems to be a cute pivot from an online plant nursery??? https://www.sublimesucculents.com/plant-for-thought-online-n...
Faster iteration does seem like it could give useful results, though unsure why they'd target plants not algae. Maybe plants are easier to contain?
Not linked on the current home page for whatever be the reason
To me this is a more sensible way than carbon tax, or even better use carbon tax to fund research like this.
I don't think that economic incentives alone might fix the situation, and maybe not even slow it down sufficiently. We need political focus, and high investment in research.
The approach from the article will take many years to provide any benefits, assuming
1) they get the efficiency increase they're aiming for
2) they can roll out these new & better plants on a large enough scale to make a difference
3) that the mass-introduction of these new plants doesn't have any unforeseen side-effects
In the short run ring fencing can provide a temporary boost in spending but in the long run all sources of funding are fungible.
You can play with the edges, but attempts to go to far with tax policy work against you.
Politics should (and often does) play a game of weights and counter-weights in economical terms to steer the society.
So yes just introducing a heavy carbon-tax is not the right solution, and I also think that long term is useless: as an example, I live in Europe where the cost of fuel is significantly higher than in the US, but traffic and fuel usage is comparable. Most likely it was lower than US in the past, but society tend to catch up anyway.
I think that something like the idea in the article is a good solution because it is not just a mere reduction, but could make carbon sequestration (via plants) useful to produce food, therefore fixing a present problem and as a byproduct also reducing a future problem.
I still think that Carbon tax is needed, but it should come in a very well thought-out packet of reforms.
(I also wrote down a more articulated answer to what I thing about carbon-tax)
Great job!
Crassulaceae (many succulents) are poisonous normally. They store acids if I remember correctly, so you can eat only very small amounts of them.
> Forest gardening is a low-maintenance, sustainable, plant-based food production and agroforestry system based on woodland ecosystems, incorporating fruit and nut trees, shrubs, herbs, vines and perennial vegetables which have yields directly useful to humans. Making use of companion planting, these can be intermixed to grow in a succession of layers to build a woodland habitat.
This statement and the remainder of that paragraph is simply nonsense. The same can be said for much of the rest of the text. They are trying to resuscitate an old idea with pure hype.
[0] http://photosynthome.irri.org/C4rice/index.php/component/con... [1] https://science.sciencemag.org/content/358/6368/1272 [2] https://science.sciencemag.org/content/363/6422/eaat9077
>410 CO2 PPM in the air means if we can magicaly cut emmisions to zero right now, there are tons of CO2 still warming the earth and they won't disappear by themselves.