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.
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.
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.
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.
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.
> 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.
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.)
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.
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.
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...
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.
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.
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.