5 ms·

One thing I've never been able to figure out is that given Crispr, why it wouldn't be possible to engineer an organism that can suck much more CO2 out of the ai

by safog 7y ago

One thing I've never been able to figure out is that given Crispr, why it wouldn't be possible to engineer an organism that can suck much more CO2 out of the air than any existing tree / algae could. Even more ideal if we can make a good building material out of the engineered plant to sequester Carbon. It's easy to see how the manual selection process would work here - plant a bunch of trees, see how much O2 each produces and pick Top N and repeat. Of course, this needs thousands of years to run manually because the improvement with each generation would be minimal. Is the issue that we don't know what gene(s) control photo-synthesis?

SamBam 7y ago
Not my area of expertise, but I would assume that there is an efficiency limit, much like there is for solar panels. Remember that organisms can't just pull CO2 out of the air for free. Plants do it via photosynthesis, which requires the sun's energy. There is a maximum amount of energy falling on each organism, and I would guess that there is some theoretical limit to the efficiency of photosynthesis that is well below that limit.
- safog 7y ago
  Yup I agree with you almost entirely. The only thing I was thinking of was if evolution would optimize for the amount of energy a plant receives vs other things like survival, reproduction etc and how much efficiency we can gain by optimizing purely for photosynthesis. Also I don’t know if plants are adapted to the high CO2 atmosphere yet so even if evolution optimized the ability of a plant to photosynthesize, given this happened in relatively low CO2 environments like forests and without man made climate change, it’s possible that human intervention can improve it.
madamelic 7y ago
>One thing I've never been able to figure out is that given Crispr, why it wouldn't be possible to engineer an organism that can suck much more CO2 out of the air than any existing tree / algae could. Jurassic Park Effect. Just because we can doesn't mean we should. CRISPR is pretty unknown and releasing man-made organism we don't know every little thing about could topple the ecosystem incredibly quickly. Not to mention how incredibly divisive it would be to do so.
gameswithgo 7y ago
trees have been optimizing that problem for a long time already, and then if you don't bury the tree and prevent decomposition, you don't really solve anything but create a short term buffer.
- hedvig 7y ago
  How long for a "full" tree to decompose?
- aaronblohowiak 7y ago
  using the lumber in high rises (through gluelam construction) is cheaper than steel and is carbon negative.. virtuous cycle indeed.
pyrale 7y ago
The answer is pretty simple: carbon fuels release energy when burned. This means an organism reversing the operation needs to absorb energy (in the case of photosynthesis, solar energy). Sunlight is not that energy-dense, and concentrating that energy too much would burn the plant anyway.
Gatsky 7y ago
This is being worked on. The problem is we are terrible at engineering biosystems, CRISPR currently works mainly to knockout genes rather than the kind of enhanced evolution you describe, and upscaling a solution to the point it can have a planetary impact is non-trivial.
- tito 7y ago
  This is the correct answer. We are abysmal at engineering biosystems. As Stewart Brand says "We are as gods and we must get good at it".
- safog 7y ago
  Re: upscaling, I was reading another article on HN about a specific species of plant when grown in sufficiently large quantities (6x size of Texas I think) would basically bring us down to carbon neutral. We can probably scrounge up that land if the world works together but who knows. Re: engineering biosystems, I imagine engineering native plants (if possible) has much fewer ecosystem wide chain effects) than using gene drives to eliminate mosquitoes or whatever. Re: crispr, I see photos of glow in the dark monkeys and super muscular dogs, so as a layman it seems like cutting a gene and vaguely throwing the desired gene near the cut location seems to work. We don’t have as many ethical implications about rapidly iterating on plants as we do on animals, so it seems like if an experiment doesn’t work, just repeat 1000x until it works would do it. People talk about off-target effects etc. but you won’t really know unless you try I guess.
soperj 7y ago
There's actually a tree that does. Paulownia. Reason is that it is also the only nitrogen fixing tree, so it can grow at a much more rapid rate.
joshmarlow 7y ago
As I understand it, algae growth is generally limited by iron, so just removing the limiting factor can increase growth and pull more CO2 out of the air. There has been at least one rogue geoengineering project along those lines - https://csi.asu.edu/ideas/the-first-of-the-geohackers/ https://csi.asu.edu/ideas/the-first-of-the-geohackers/ Maybe we don't actually need genetic engineering - maybe we can just build big algae ponds and feed them iron supplements. Basically build algae heaven, open source it and random groups across the globe can start doing it.

by safog 7y ago

SamBam 7y ago

Not my area of expertise, but I would assume that there is an efficiency limit, much like there is for solar panels. Remember that organisms can't just pull CO2 out of the air for free. Plants do it via photosynthesis, which requires the sun's energy. There is a maximum amount of energy falling on each organism, and I would guess that there is some theoretical limit to the efficiency of photosynthesis that is well below that limit.

safog 7y ago
Yup I agree with you almost entirely. The only thing I was thinking of was if evolution would optimize for the amount of energy a plant receives vs other things like survival, reproduction etc and how much efficiency we can gain by optimizing purely for photosynthesis. Also I don’t know if plants are adapted to the high CO2 atmosphere yet so even if evolution optimized the ability of a plant to photosynthesize, given this happened in relatively low CO2 environments like forests and without man made climate change, it’s possible that human intervention can improve it.

madamelic 7y ago

>One thing I've never been able to figure out is that given Crispr, why it wouldn't be possible to engineer an organism that can suck much more CO2 out of the air than any existing tree / algae could. Jurassic Park Effect. Just because we can doesn't mean we should. CRISPR is pretty unknown and releasing man-made organism we don't know every little thing about could topple the ecosystem incredibly quickly. Not to mention how incredibly divisive it would be to do so.

gameswithgo 7y ago

trees have been optimizing that problem for a long time already, and then if you don't bury the tree and prevent decomposition, you don't really solve anything but create a short term buffer.

hedvig 7y ago
How long for a "full" tree to decompose?
aaronblohowiak 7y ago
using the lumber in high rises (through gluelam construction) is cheaper than steel and is carbon negative.. virtuous cycle indeed.

pyrale 7y ago

The answer is pretty simple: carbon fuels release energy when burned. This means an organism reversing the operation needs to absorb energy (in the case of photosynthesis, solar energy). Sunlight is not that energy-dense, and concentrating that energy too much would burn the plant anyway.

Gatsky 7y ago

This is being worked on. The problem is we are terrible at engineering biosystems, CRISPR currently works mainly to knockout genes rather than the kind of enhanced evolution you describe, and upscaling a solution to the point it can have a planetary impact is non-trivial.

tito 7y ago
This is the correct answer. We are abysmal at engineering biosystems. As Stewart Brand says "We are as gods and we must get good at it".
safog 7y ago
Re: upscaling, I was reading another article on HN about a specific species of plant when grown in sufficiently large quantities (6x size of Texas I think) would basically bring us down to carbon neutral. We can probably scrounge up that land if the world works together but who knows. Re: engineering biosystems, I imagine engineering native plants (if possible) has much fewer ecosystem wide chain effects) than using gene drives to eliminate mosquitoes or whatever. Re: crispr, I see photos of glow in the dark monkeys and super muscular dogs, so as a layman it seems like cutting a gene and vaguely throwing the desired gene near the cut location seems to work. We don’t have as many ethical implications about rapidly iterating on plants as we do on animals, so it seems like if an experiment doesn’t work, just repeat 1000x until it works would do it. People talk about off-target effects etc. but you won’t really know unless you try I guess.

soperj 7y ago

There's actually a tree that does. Paulownia. Reason is that it is also the only nitrogen fixing tree, so it can grow at a much more rapid rate.

joshmarlow 7y ago

As I understand it, algae growth is generally limited by iron, so just removing the limiting factor can increase growth and pull more CO2 out of the air. There has been at least one rogue geoengineering project along those lines - https://csi.asu.edu/ideas/the-first-of-the-geohackers/ https://csi.asu.edu/ideas/the-first-of-the-geohackers/ Maybe we don't actually need genetic engineering - maybe we can just build big algae ponds and feed them iron supplements. Basically build algae heaven, open source it and random groups across the globe can start doing it.