3 ms·

Not going to lie, 4000 tons annually is kind of disappointing. Even if you had 100,000 of these plants (that's three times more than the number of starbucks on

Not going to lie, 4000 tons annually is kind of disappointing. Even if you had 100,000 of these plants (that's three times more than the number of starbucks on the planet), that is still less than the gigatons of removal required to make a significant dent in the CO2 already present in the atmosphere. Not to mention I bet these are far more expensive to create/maintain than a Starbucks... Clean sequestration of plant matter and significant emissions reductions are really the only paths forward.

jasonlaramburu 5y ago
The most expensive/capital intensive part of Direct Air Capture is the CO2 extraction, since CO2 is relatively low concentration in air. Conversion of waste biomass into biochar is both more capital efficient and energy efficient, since the plants themselves facilitate the CO2 extraction.
- Teknoman117 5y ago
  You just need a lot of surface area to grow that many plants. Does conversion to "biochar" allow recovery of the nutrients you need to grow more plants? Or are we also sequestering nitrates, phosphorous, etc. as well?
  - jasonlaramburu 5y ago
    Yes it does, the pyrolysis conditions (the process to make biochar) will influence what % of nutrients are recovered in a plant available form. We could actually capture gigatons using only the leftover waste from our current commercial agricultural production.
Teknoman117 5y ago
> Vastly larger DAC facilities are on the horizon. Carbon Engineering Ltd., a Canadian firm, is planning two plants that could each capture up to 1 million metric tons of carbon dioxide annually. A 100-acre facility is expected to break ground in the Permian Basin next year. The other, slated for construction in Scotland, could begin operations in 2026. > By comparison, it would take over 1.2 million acres of U.S. forestland to sequester an equivalent amount of carbon over the same time period, EPA data shows. Assuming these numbers are actually realistic, and you have an abundance of available carbon neutral energy (whether that's solar, wind, thermal, small-scale nuclear, etc.), it doesn't seem too far fetched (on a cursory glance) to hit gigaton scale carbon removal. 100 acres per megaton/yr of carbon dioxide would mean 400 sq. km of plant per gigaton of removal capacity.
- Ancalagon 5y ago
  That's a minimum 1000 of these giant facilities to even scratch the surface of what the article mentioned would be required to see dramatic improvements in climate change. The article mentioned the first one of those will take ~5 years from now to come online. In that time, we will have emitted far more carbon than can ever be captured by those facilities. I don't think we have the time to wait for (minimum) 1000 of these facilities to come on line. I mean, they would help some, no doubt, but proper forest management and logging is existing knowledge, and the best part is the forests can mostly manage themselves. Forests are scaleable, and could be huge carbon sinks given the right speciation. The logging companies would be paid to cut the forests down, and sink them to the bottom of the ocean/turn them into biochar. Additionally, something similar could be done with kelp-forests (and I believe a startup already is doing just this). Scale is the issue here, what better way to scale planet-wide than self-reproducing carbon-capture technology (plants)?
  - Teknoman117 5y ago
    I was mainly thinking of construction resulting from unilateral action. Obviously we aren't going to lazily get there building one at a time. Forest building is great, but to sink similar amounts of carbon, you'd need to plant tens of billions of acres of new plants every year. Essentially, the same amount of plants that we're burning the ancient corpses of.
    - Ancalagon 5y ago
      Right, I just think scaling construction of these facilities would require infrastructure that could take a decade plus to get right. You are right forestry is not the place we should focus right now. The main problem right now is turning off coal plants, among other CO2 reduction strategies.

jasonlaramburu 5y ago

The most expensive/capital intensive part of Direct Air Capture is the CO2 extraction, since CO2 is relatively low concentration in air. Conversion of waste biomass into biochar is both more capital efficient and energy efficient, since the plants themselves facilitate the CO2 extraction.

Teknoman117 5y ago
You just need a lot of surface area to grow that many plants. Does conversion to "biochar" allow recovery of the nutrients you need to grow more plants? Or are we also sequestering nitrates, phosphorous, etc. as well?
- jasonlaramburu 5y ago
  Yes it does, the pyrolysis conditions (the process to make biochar) will influence what % of nutrients are recovered in a plant available form. We could actually capture gigatons using only the leftover waste from our current commercial agricultural production.

Teknoman117 5y ago

> Vastly larger DAC facilities are on the horizon. Carbon Engineering Ltd., a Canadian firm, is planning two plants that could each capture up to 1 million metric tons of carbon dioxide annually. A 100-acre facility is expected to break ground in the Permian Basin next year. The other, slated for construction in Scotland, could begin operations in 2026. > By comparison, it would take over 1.2 million acres of U.S. forestland to sequester an equivalent amount of carbon over the same time period, EPA data shows. Assuming these numbers are actually realistic, and you have an abundance of available carbon neutral energy (whether that's solar, wind, thermal, small-scale nuclear, etc.), it doesn't seem too far fetched (on a cursory glance) to hit gigaton scale carbon removal. 100 acres per megaton/yr of carbon dioxide would mean 400 sq. km of plant per gigaton of removal capacity.

Ancalagon 5y ago
That's a minimum 1000 of these giant facilities to even scratch the surface of what the article mentioned would be required to see dramatic improvements in climate change. The article mentioned the first one of those will take ~5 years from now to come online. In that time, we will have emitted far more carbon than can ever be captured by those facilities. I don't think we have the time to wait for (minimum) 1000 of these facilities to come on line. I mean, they would help some, no doubt, but proper forest management and logging is existing knowledge, and the best part is the forests can mostly manage themselves. Forests are scaleable, and could be huge carbon sinks given the right speciation. The logging companies would be paid to cut the forests down, and sink them to the bottom of the ocean/turn them into biochar. Additionally, something similar could be done with kelp-forests (and I believe a startup already is doing just this). Scale is the issue here, what better way to scale planet-wide than self-reproducing carbon-capture technology (plants)?
- Teknoman117 5y ago
  I was mainly thinking of construction resulting from unilateral action. Obviously we aren't going to lazily get there building one at a time. Forest building is great, but to sink similar amounts of carbon, you'd need to plant tens of billions of acres of new plants every year. Essentially, the same amount of plants that we're burning the ancient corpses of.
  - Ancalagon 5y ago
    Right, I just think scaling construction of these facilities would require infrastructure that could take a decade plus to get right. You are right forestry is not the place we should focus right now. The main problem right now is turning off coal plants, among other CO2 reduction strategies.