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Comment by peytoncasper | Hacker News Reader

The sense of scale is fascinating.

Each facility will have a goal of scrubbing 1 million tons of CO2/yr.

However, we currently emit 30+ Billion tons of CO2/yr.

If it works and it's economical there's no reason to think that you couldn't build 30,000 of them. I would expect that the people who only care about profits to quickly allocate capital to this endeavor (if it's profitable) up until the point where diminishing returns makes it less profitable. Hopefully that doesn't happen until we're slowly decreasing CO2 versus slowly increasing.

Even just cutting the growth rate by half would do a lot, and it would give international bodies like the UN some footing to establish a carbon price. Right now the carbon market is highly illiquid; nowhere near enough people are able to manufacture credits. If you could guarantee that it's always possible to make more credits that changes the political and perhaps even economic dynamic.

Or go the rasberry pi route and produce household units inexpensively or free DIY plans.

Crowd-source it to municipalities and makers.

Unfortunately I suspect this is tech that scales with efficiency in a crazy way like inverse power plants. You'd likely get much greater returns and efficiencies from a few large facilities.

Don't get me wrong if they build a sink which can be deployed at a household level which is 80% efficient and a huge city one is only 90% efficient it might be worth going this route. But I suspect the numbers would be closer to 50% and 99% based on current technologies (granted I don't work in the sector I just read publications)

You mean trees?

Tree aren't great for carbon capture. They take up land space, which then has to be reserved for those trees. Then, they eventually die, and decompose, which means a new tree has to grow to re-capture the carbon that is released when the tree decomposes. Better to put the excess carbon back underground, where it came from.

The term is “sequestration”. You are correct that trees are a temporary capture, and even then- only when you plant woodlands that did not previously exist. Given enough time, the trees that are planted will decompose or burn in a forest fire to become net neutral. Trees buy time, but they aren’t a clean up plan.

Trees decomposing and being consumed by other trees is literally how it's worked for untold millions of years, so doesn't seem like a problem to me ...

Forests also provide local cooling, improve the water cycle, and aid biodiversity. A world with forests is a healthier world.

Trees dying and not decomposing is how we got all that coal that we're now turning back to CO2.

It's also how we got all the carbon in our top soils. A 6 inch or more covering of carbon (mixed with minerals etc) covering huge parts of the earth's surface.

Planting trees, harvesting them, and turning them by pyrolysis into biochar/charcoal and then burying it can partially restore these soils and sequester carbon at the same time.

Yep, but it is a nontrivial amount of work to produce approximately as much biochar as we have burnt coal.

Oh, absolutely. It would take generations. But taking forestry waste and turning it into a soil amendment is a worthwhile endeavour even from the POV of improving food production.

Also, as we're seeing in the US west or Siberian forests; they cascade co2 release quickly with forest fires.

A recent thought on carbon credit scheme with trees. If you grow a tree and build a house with it, then that carbon is captured until the house burns down.

> If it works and it's economical there's no reason to think that you couldn't build 30,000 of them.

That would just leave us where we're at right now, right? Even with emissions not increasing (unlikely...), we'd still need 60k just to decrease CO2 levels at the same rate... meaning it'd take several decades to bring them to acceptable levels. We'd probably need a few times that many facilities to be able to do this at the pace we need...

Today is not a bad place to be, especially compared to many of the other potential outcomes.

It beats the alternative that's likely to happen, which is "oops, nobody told me it was going to break!"

If you held emissions constant, yes, but realistically you'd also be reducing emissions at the same time.

We'll have to build an assembly line for them.

1 facility for every ~100k people isn't unreasonable. It's like building an air treatment plant for every water treatment plant there is. Anyway, while these plants are busy reprocessing the entire planet's atmosphere they can do other useful things besides removing CO2.

Interested to know what those "other things" might be.

Any activity with carbon that doesn't involve aerobic activity. Creating soil (worms or bokashi vs compost), creating plastic, creating pencil lead.

That gives an interesting sense of scale to the problem. Dealing with C02 emissions is similar to water waste treatment, both in concept and in scale of infrastructure required.

Why would it be economical? It's burning power. There's no business model beyond "get governments to pay".

Yes the scale is fascinating! 2018 per capita emissions in the USA are 15 tons of carbon dioxide per person. So 1 million tons is the yearly emissions for 66,666 people.

Still early days. We need to get 2x better at carbon removal every 12 months for the next decade to get to gigaton scale carbon removal.

See my note about AirMiners Boot Up below http://bootup.airminers.org

30 billion+ and growing at roughly 5% annually. That means 1.5 billion tons CO2/yr, or 1,500 new facilities coming online this year and every year after... just to maintain our current (devastatingly high) CO2 levels.

All this talk about scaling the technology to fully draw down carbon feels like an fantasy if we can't even proven the concept of keeping pace with our year-over-year growth.

If the cost of removal is a mere $100 per ton of carbon, the annual cost of removing 30 billion tons of C02 would be $3 Trillion. (3,000,000,000,000)

The cost for most of these technologies right now is over $400 per ton, so that works out to $12 trillion.

Yikes.

So - twice the cost of the war in Afghanistan per year, after financing is calculated?

For comparison, the Gross World Product is about $90 Trillion, so a global sales tax of about 3% would cover the lower figure.

Another way to look at it is that the GWP has an average growth rate of over 3%, so economic growth could continue even if the $3 Trillion spent per year was considered economically unproductive.

https://en.wikipedia.org/wiki/Gross_world_product

For comparison, estimates of the yearly costs created by 1.5 degree warming seems to be around 5T/year (e.g. [1]).

[1] https://www.nature.com/articles/s41598-020-66275-4

I actually thought that sounds kind of cheap. On average each German person emits roughly 10 tons of carbon per year. So for a $1000 dollars per year, I can be carbon neutral without any additional changes? Sounds pretty good to me.

I feel like just letting the climate change over the next 100 years and adapting as needed would be cheaper than spending $1.2 quadrillion on a global geo-engineering project.

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