11 ms·

Instead of elaborate carbon capture infrastructure, it seems more straightforward to just use photosynthetic organisms like algae. Either engineer algae to make

by howlin 4y ago

Instead of elaborate carbon capture infrastructure, it seems more straightforward to just use photosynthetic organisms like algae. Either engineer algae to make the proteins you want, or engineer yeast or some other microbe that can take the products of algae and convert to these proteins. Honestly it sounds like a needless and impractical gimmick.

ehnto 4y ago
I wouldn't call bioengineering and it's effects on the ecosystem a straightforward endeavor.
bnjemian 4y ago
It's not like it gets you nothing; photosynthesis would be much less efficient in terms of the land footprint required. The article discusses the footprint required for their facilities relative to normal agriculture; the difference is massive. Photosynthesis is effectively driven by a 2D flux and thus is constrained by surface area to a pretty large extent – unless you use an electric light source, which would require renewable energy to be sustainable and thus, again, be constrained by surface area (think wind farms and PVs). With their technology, they can use a bioreactor and aerate it with the CO2, etc. required to grow the microbes they're using. That means the energy is not constrained to a 2D flux and can be delivered across all three dimensions in a volume.
throwawaymaths 4y ago
It's not. Photosynthesis is two steps: 1. Assimilating photons from sunlight to generate electrical potential by oxidizing water (ps that is kind of a crazy concept). 2. Fixing carbon dioxide by using the electron from step one to reduce CO2 to C-OH (ish) 1. Photosystem-II-I systems really suck, like, commercially available photocells are more efficient than fundamental quantum limits of the protein complex, beyond what it is likely for us to be able to do design or evolve for. Our photocells are getting better too. Also, photosynthetic organisms, especially algae, self-shadow. That's why you almost have to have those rediculous algae racetracks (look it up) and of course often the least valuable land + where there is sunlight so that it stands a chance to make economical sense is often in the desert, so for algae you're stuck shipping water to the desert :/ 2. Carbon fixation really really sucks. RuBisCo is the enzyme that is the bottleneck. It sucks so hard that RuBisCo is literally the most abundant enzyme on the planet to make up for how bad it is. Not only is it an annoyingly slow enzyme, it's oxygen sensitive, which is hilarious because step 1 of photosynthesis cracks water. Plants and algae do some crazy gymnastics to separate part 1 and part 2; look up C3 and C4 cycles, and algae had to invent colonial forms and terminal differentiation because their carbon fixers are kept segregated from their photosynthesizers; one algae -synechocystis 6803 has one of the biggest algae genomes, it probably mostly goes into a rigourous gene expression which is used to anticipate circadian cycles and prepare the cell to flip between day (photosystem) and night (carbon and nitrogen fixation) cycles.
ravenstine 4y ago
Or we can just have plants capture the CO2, give those plants to large ruminants which will feed those plants to the microbiota in their cecum, digest the microbiota and converting it into the kind of nutritious protein and fat that hominids have adapted to digest almost exclusively for millions of years. If one is worried about the methane emissions of cattle, it's not really clear that this is even a secondary concern. The carbon that cows produce, whether it be methane or CO2, came from the atmosphere and is returned to the atmosphere. That is because cows are eating plants which derive their carbon primarily from the atmosphere. This is different from fossil sources of methane, which isn't atmospheric unless it's released. The isotope of carbon isn't even the same between bio-methane and fossil methane. The methane that cows release is oxidized after several years.
- pxeger1 4y ago
  Meat farming takes in CO2 (photosynthesis), and produces CO2 (cows breathing) and CH4 (cows farting). CH4 is a much more potent greenhouse gas than CO2, so, even by your flawed simplified model, farming cows has a net negative greenhouse effect.
  - ravenstine 4y ago
    So what if methane is more "potent"? How potent and in relation to what, and in what amount? Large ruminants and other animals that produce methane roamed the Earth in greater numbers long before humans came up with the concept of livestock. Stable isotopes of carbon in atmospheric methane don't support livestock being a contributor to rising methane at all. Because livestock methane is part of the carbon cycle, and livestock aren't in greater numbers, problematic increases in atmospheric methane have to be coming from somewhere else, most likely things such as fracking. Carbon-14 would be increasing in the atmosphere if cows were responsible. Even if we eliminated meat consumption, hypothetically speaking, it's totally unclear and unfounded that any meaningful difference would be made. According to the United States EPA, agriculture as a whole makes up 11% of greenhouse gas emissions in the United States. That percentage includes everything from farm to table, meaning that cows in particular make up a fraction of that since most of the greenhouse gas will inevitably come from transportation and processing. Methane itself makes up ~11% of greenhouse gas. Show me any evidence whatsoever that correcting for the greenhouse gas from animals bred for food will make any appreciable difference in changing the climate in the favor of humans. By the way, most of the methane from cows comes from their burping, not farting.

by howlin 4y ago

ehnto 4y ago

I wouldn't call bioengineering and it's effects on the ecosystem a straightforward endeavor.

bnjemian 4y ago

It's not like it gets you nothing; photosynthesis would be much less efficient in terms of the land footprint required. The article discusses the footprint required for their facilities relative to normal agriculture; the difference is massive. Photosynthesis is effectively driven by a 2D flux and thus is constrained by surface area to a pretty large extent – unless you use an electric light source, which would require renewable energy to be sustainable and thus, again, be constrained by surface area (think wind farms and PVs). With their technology, they can use a bioreactor and aerate it with the CO2, etc. required to grow the microbes they're using. That means the energy is not constrained to a 2D flux and can be delivered across all three dimensions in a volume.

throwawaymaths 4y ago

It's not. Photosynthesis is two steps: 1. Assimilating photons from sunlight to generate electrical potential by oxidizing water (ps that is kind of a crazy concept). 2. Fixing carbon dioxide by using the electron from step one to reduce CO2 to C-OH (ish) 1. Photosystem-II-I systems really suck, like, commercially available photocells are more efficient than fundamental quantum limits of the protein complex, beyond what it is likely for us to be able to do design or evolve for. Our photocells are getting better too. Also, photosynthetic organisms, especially algae, self-shadow. That's why you almost have to have those rediculous algae racetracks (look it up) and of course often the least valuable land + where there is sunlight so that it stands a chance to make economical sense is often in the desert, so for algae you're stuck shipping water to the desert :/ 2. Carbon fixation really really sucks. RuBisCo is the enzyme that is the bottleneck. It sucks so hard that RuBisCo is literally the most abundant enzyme on the planet to make up for how bad it is. Not only is it an annoyingly slow enzyme, it's oxygen sensitive, which is hilarious because step 1 of photosynthesis cracks water. Plants and algae do some crazy gymnastics to separate part 1 and part 2; look up C3 and C4 cycles, and algae had to invent colonial forms and terminal differentiation because their carbon fixers are kept segregated from their photosynthesizers; one algae -synechocystis 6803 has one of the biggest algae genomes, it probably mostly goes into a rigourous gene expression which is used to anticipate circadian cycles and prepare the cell to flip between day (photosystem) and night (carbon and nitrogen fixation) cycles.

ravenstine 4y ago

Or we can just have plants capture the CO2, give those plants to large ruminants which will feed those plants to the microbiota in their cecum, digest the microbiota and converting it into the kind of nutritious protein and fat that hominids have adapted to digest almost exclusively for millions of years. If one is worried about the methane emissions of cattle, it's not really clear that this is even a secondary concern. The carbon that cows produce, whether it be methane or CO2, came from the atmosphere and is returned to the atmosphere. That is because cows are eating plants which derive their carbon primarily from the atmosphere. This is different from fossil sources of methane, which isn't atmospheric unless it's released. The isotope of carbon isn't even the same between bio-methane and fossil methane. The methane that cows release is oxidized after several years.

pxeger1 4y ago
Meat farming takes in CO2 (photosynthesis), and produces CO2 (cows breathing) and CH4 (cows farting). CH4 is a much more potent greenhouse gas than CO2, so, even by your flawed simplified model, farming cows has a net negative greenhouse effect.
- ravenstine 4y ago
  So what if methane is more "potent"? How potent and in relation to what, and in what amount? Large ruminants and other animals that produce methane roamed the Earth in greater numbers long before humans came up with the concept of livestock. Stable isotopes of carbon in atmospheric methane don't support livestock being a contributor to rising methane at all. Because livestock methane is part of the carbon cycle, and livestock aren't in greater numbers, problematic increases in atmospheric methane have to be coming from somewhere else, most likely things such as fracking. Carbon-14 would be increasing in the atmosphere if cows were responsible. Even if we eliminated meat consumption, hypothetically speaking, it's totally unclear and unfounded that any meaningful difference would be made. According to the United States EPA, agriculture as a whole makes up 11% of greenhouse gas emissions in the United States. That percentage includes everything from farm to table, meaning that cows in particular make up a fraction of that since most of the greenhouse gas will inevitably come from transportation and processing. Methane itself makes up ~11% of greenhouse gas. Show me any evidence whatsoever that correcting for the greenhouse gas from animals bred for food will make any appreciable difference in changing the climate in the favor of humans. By the way, most of the methane from cows comes from their burping, not farting.