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This system proposes removing 30 millions tons per year. A tree captures about 20 tons of carbon dioxide per year. So this is the equivalent to 1.5 million tr

by tito 3y ago

This system proposes removing 30 millions tons per year. A tree captures about 20 tons of carbon dioxide per year. So this is the equivalent to 1.5 million trees. Trees grow at about 800 trees per acre. This effectively matches the space of 1,875 acres, around 3 square miles. So in a way one could think of this as opening up more land for other things.

ianburrell 3y ago
Someone else mentioned needing to remove 10 billion tons by 2050. That is 1000 sq mi, which is size of Luxembourg. That is doable but have to do every year. My guess is that we’ll run out of good forest spots. Or climate change will kill all the trees.
- otterley 3y ago
  I think that's the wrong comparison. Sure, 1000 sq mi is the size of Luxemberg, but the entire earth's land surface is over 57 million square miles (yes, I realize only a fraction of that is usable for tree planting). If we assume the planting density is correct, that's around 0.0000175% of surface area needed. Not much at all, proportionately speaking.
  - ianburrell 3y ago
    It makes me suspect that the numbers are off. I found estimate that tree absorbs 20-30kg of CO2 per year. Each cubic meter absorbs 1 ton of CO2. I can't think of any tree grows fast enough for 20 tons. I bet it was originally 20kg not 20 tons. Which means my estimate is 1000 times small. 1 million sq mi is Argentina. Which means we can absorb some CO2 with trees but there isn't enough land for what is needed.
    - otterley 3y ago
      > I bet it was originally 20kg not 20 tons. I think you're right. Oof, that's a lot of trees. Still worth doing IMO. Keep in mind we can divide by 10 since each tree would absorb approximately 250 kg of CO2 over that period of time. That brings us to about 78,000 square miles or 20M hectares, which seems a lot more feasible.
      - tito 3y ago
        Oh you're totally right, 20 kg, not 20 tons. My bad. In a year, 1 tree removes the equivalent emissions of 2 gallons of gasoline.
footlose_3815 3y ago
Why even have trees? They seem outdated. /s
- tito 3y ago
  Climate models say we need to be removing about 10 billion tons per year of carbon dioxide from the air by 2050, in addition to massive decarbonization. So we need trees, this stuff, and a lot more. A new $1T industry in the next 27 years.
  - otterley 3y ago
    I dunno. $1T buys a lot of land - if we assume the amount of forest needed to reduce 10B tons of CO2 over 10 years is 50 million acres, $1T would pay $20,000/acre. That's way more than a lot of acreage goes for that you could put trees on. Put in that light, spending $1T on some sort of magic engineered CO2 vacuum gizmo that has yet to be fully baked, will probably break down from time to time, and won't scale particularly well seems like a bad investment. No disrespect intended, just doing the math.
    - tito 3y ago
      Carbon removal is on track to be a $1T industry per year. There's that much excess carbon dioxide in the air. The scale that's needed is far beyond what trees can do. And trees have their own complications - carbon release (fires, virus, death), measurement, and attractiveness to chop down and use for other stuff. Trees haven't (yet) been optimized as carbon removal and storage devices. They just happen to be somewhat decent at it, but with some shortcomings. I wrote more about carbon removal in my weekly newsletter here: https://tito.co/posts/do-you-think-we-need-carbon-removal-for-a-stable-climate.html https://tito.co/posts/do-you-think-we-need-carbon-removal-fo...
nvm0n2 3y ago
Remember that the machines require electricity, so you have to also include the land needed by the power generation and transmission equipment. And assume that the power comes only from CO2-neutral sources (very dubious assumption). And then we remember that vacuums make a lot of noise and people don't like living near noise, whereas living next to a forest is fine, so you need land padding too.
- tito 3y ago
  Completely agree, need to factor it all in.
otterley 3y ago
We have plenty of land today. It's just not being used particularly efficiently. Suburban development and single-family housing in particular is incredibly space-inefficient. Also, 3 square miles is not that much at all. The USA is almost 4 million square miles in area.
tito 3y ago
edit: 20 kg of CO2, not 20 tons. This system proposes removing 30 millions tons per year. A tree captures about 0.02 tons of carbon dioxide per year. So this is the equivalent to 1.5 billion trees. Trees grow at about 800 trees per acre. This effectively matches the space of 1.875 million acres, around 2,929 square miles. So in a way one could think of this as opening up more land for other things.

by tito 3y ago

ianburrell 3y ago

Someone else mentioned needing to remove 10 billion tons by 2050. That is 1000 sq mi, which is size of Luxembourg. That is doable but have to do every year. My guess is that we’ll run out of good forest spots. Or climate change will kill all the trees.

otterley 3y ago
I think that's the wrong comparison. Sure, 1000 sq mi is the size of Luxemberg, but the entire earth's land surface is over 57 million square miles (yes, I realize only a fraction of that is usable for tree planting). If we assume the planting density is correct, that's around 0.0000175% of surface area needed. Not much at all, proportionately speaking.
- ianburrell 3y ago
  It makes me suspect that the numbers are off. I found estimate that tree absorbs 20-30kg of CO2 per year. Each cubic meter absorbs 1 ton of CO2. I can't think of any tree grows fast enough for 20 tons. I bet it was originally 20kg not 20 tons. Which means my estimate is 1000 times small. 1 million sq mi is Argentina. Which means we can absorb some CO2 with trees but there isn't enough land for what is needed.
  - otterley 3y ago
    > I bet it was originally 20kg not 20 tons. I think you're right. Oof, that's a lot of trees. Still worth doing IMO. Keep in mind we can divide by 10 since each tree would absorb approximately 250 kg of CO2 over that period of time. That brings us to about 78,000 square miles or 20M hectares, which seems a lot more feasible.
    - tito 3y ago
      Oh you're totally right, 20 kg, not 20 tons. My bad. In a year, 1 tree removes the equivalent emissions of 2 gallons of gasoline.

footlose_3815 3y ago

Why even have trees? They seem outdated. /s

tito 3y ago
Climate models say we need to be removing about 10 billion tons per year of carbon dioxide from the air by 2050, in addition to massive decarbonization. So we need trees, this stuff, and a lot more. A new $1T industry in the next 27 years.
- otterley 3y ago
  I dunno. $1T buys a lot of land - if we assume the amount of forest needed to reduce 10B tons of CO2 over 10 years is 50 million acres, $1T would pay $20,000/acre. That's way more than a lot of acreage goes for that you could put trees on. Put in that light, spending $1T on some sort of magic engineered CO2 vacuum gizmo that has yet to be fully baked, will probably break down from time to time, and won't scale particularly well seems like a bad investment. No disrespect intended, just doing the math.
  - tito 3y ago
    Carbon removal is on track to be a $1T industry per year. There's that much excess carbon dioxide in the air. The scale that's needed is far beyond what trees can do. And trees have their own complications - carbon release (fires, virus, death), measurement, and attractiveness to chop down and use for other stuff. Trees haven't (yet) been optimized as carbon removal and storage devices. They just happen to be somewhat decent at it, but with some shortcomings. I wrote more about carbon removal in my weekly newsletter here: https://tito.co/posts/do-you-think-we-need-carbon-removal-for-a-stable-climate.html https://tito.co/posts/do-you-think-we-need-carbon-removal-fo...

nvm0n2 3y ago

Remember that the machines require electricity, so you have to also include the land needed by the power generation and transmission equipment. And assume that the power comes only from CO2-neutral sources (very dubious assumption). And then we remember that vacuums make a lot of noise and people don't like living near noise, whereas living next to a forest is fine, so you need land padding too.

tito 3y ago
Completely agree, need to factor it all in.

otterley 3y ago

We have plenty of land today. It's just not being used particularly efficiently. Suburban development and single-family housing in particular is incredibly space-inefficient. Also, 3 square miles is not that much at all. The USA is almost 4 million square miles in area.

tito 3y ago

edit: 20 kg of CO2, not 20 tons. This system proposes removing 30 millions tons per year. A tree captures about 0.02 tons of carbon dioxide per year. So this is the equivalent to 1.5 billion trees. Trees grow at about 800 trees per acre. This effectively matches the space of 1.875 million acres, around 2,929 square miles. So in a way one could think of this as opening up more land for other things.