The problem is you cannot plant enough trees around the globe to offset our CO2 emissions. Also, a forest only absorbs CO2 while alive. Once it dies, it emits CO2 too. You would need to permanently store the wood somewhere (submerging in water, etc).

Recent article: https://www.theguardian.com/environment/2025/nov/28/africa-f...

>Economics rules everything

Physics rules everything, once you start trying to run at scale.

The density of carbon per unit volume in solid materials of interest doesn't vary that much, whether you sink it in trees or in exotic materials like diamonds. That means you can calculate the volume of material required so sink a desired amount of atmospheric carbon.

If you want to have a measurable impact on the atmosphere, say dialing it back to 1980 CO2 levels, you're talking not about making a pile of stuff but about making a mountain range that's a mile high and hundreds of miles long.

Now figure out how many trucks you're going to need to move that much material from where your sequestering machine is to where your pile of stuff is.

Or if you want to dump that material in the ocean (which someone else will certainly object to), extend your calculation to figure out how many container trucks worth of material you need to dump into the ocean every hour to accomplish your atmospheric cleanup in whatever amount of time you choose (a decade? If it takes a century, that's not fast enough).

And finally think about surface to volume ratios. You're trying to sink it into a volume, but you can only get the gas into the volume through its surface, so the speed of your process is limited by surface area.

If you want to do it with trees, my personal spitball estimates are that you probably need to plant somewhere between the entire state of Connecticut and the entire state of Colorado to have the kind of impact one would want (there's more subtlety to tree calculations than one generally likes to admit, so feel free to come in with way higher numbers than I did).

Which brings us back to economics. If you have a well-managed forest of that size and scale, someone is eventually going to come along, maybe in 100 years, maybe in 500 years, and say "hey if we cut this down, we could burn the wood to heat our homes" and all that carbon goes back into the atmosphere, so you actually need to sink it into something that is energetically unfavorable for recovery, which means you also need to expand a huge amount of energy to sink the carbon into that energetically unfavorable state.

In the order of importance:

1. Even if we do magic and emit nothing, we still need to remove CO2 from the atmosphere or it will cook us over time, just longer.

2. We would need an enormous area for forests (which i great), which would mean a lot of intervention, like resettling people, demolishing and constructing new buildings, a lot of machinery time to move people to and from the new forests, a lot of planting and forest maintenance involved. And add he work to cut and bury resulting wood. If you would sum all the incidental emissions from this process it would rapidly become much less efficient (if at all).

Without either CO2 capture or a sun shade of some sort, the CO2 levels and temperature will only ever increase, just like now.

I agree. Plants are not very efficient (1% or 2%) but they include packaging the CO2 in a stable form. You can store the grain or wood for long periods of times.

In this case, it looks like they get CO2 as a gas. It's cheaper because you don't have to use energy to undo the burning, but it's difficult to store for a long time.

(I'm not sure if someone tried to make a fake underground bog in abandoned mine. Just fill with wood and water to keep the oxygen low and make the wood decompose slowly.)

Planting trees is not effective since it takes decades to capture the carbon, but the next years are crucial for determining long term climate developments.

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