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Comment by ph0rque | Hacker News Reader

Not to sound like a broken record, but for the average American, $15/person/year will plant enough trees to offset all the CO2 released into the atmosphere by that person: http://shindyapin.tumblr.com/post/141034501197/climate-chang...

Why aren't we doing it? Because nobody is forcing us, and very few are doing it voluntarily.

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To extrapolate, then, we can solve this for $15 * 300,000,000 = $4.5 billion for the US? And if we are 25% of the world's carbon production (I'm pulling this out of the air) then we can do this for $18 billion? This is on the order of a 10th of a percent of GDP per year. Can it really be that low?

I don't see how this could work. You need a place to plant all of those trees and let them grow and then store them so that they don't decompose and release CO2 back into the atmosphere. That's a lot of land and it seems like if you continually harvest trees without letting them decompose you'll need to fertilize the land to keep the trees growing well.

You can convert the trees to biochar, then a large percentage won't decompose. You don't need to fertilize trees because they get their nutrients from microbial life[0], which is increased by fertilization with biochar.

[0] elane ingham, food web talk - https://m.youtube.com/watch?v=x2H60ritjag

Microbial life has to get the nutrients from somewhere, so you do need fertilizer and the biochar is the fertilizer. It's not impossible to sequester carbon this way, it's just that it seems like it's going to cost significantly more than $15/person/year.

The soil has unavailable nutrients in large supplies that get converted by microbes. The biochar is technically inert and doesn't get absorbed, it stimulates microbial life because it has massive amounts of surface area. It's not technically necessary.

My calculations assume a tree will sequester the carbon for 10 years. I'm sure we can do a lot better than that, but even with these assumptions, it's pretty cheap to sequester the CO2 on an ongoing basis.

Timber buildings.

Yes, and also food (fruits, leaves, etc), medicine, wooden furniture, clothes (http://www.treehugger.com/clean-technology/will-your-next-t-...), and many other items.

As far as your other concerns, they become a problem at scale. Which is what startups are all about solving, right?

I don't see how startups would help this, but this only becomes useful at scale so if it doesn't scale it's not useful. If we had unlimited land to grow things on we would have far fewer problems to begin with, but land is rapidly being cleared of trees for farming. Since we're already decreasing the amount of land we use to grow trees, we could just stop doing that instead.

I was merely pointing out that startups are good at solving problems that arise from taking products to scale.

The organization I linked to helps families grow food forests, so they both farm and plant trees on a given piece of land.

As pointed out elsewhere, we probably don't have enough land for that many trees, unless we figure out how to grow forests in the deserts or on floating islands in the ocean, etc. (technically possible, but not trivial). That misses the important fact, though: there are millions of acres where trees can be planted now. If we run out of land to plant trees on, we can solve that problem at that point.

It's like Climate Change has been engineered to play on our worst behavioral tendencies. It's the ultimate behavioral science problem. As a species, we tend to want to deal with things "tomorrow", and have a hard time identifying non-immediate, gradual, threats.

There's probably some surivor bias going on there - we don't really notice the threats that are easy to solve, because we solve them.

Cool Earth [1] is a highly rated [2] charity fighting climate change.

[1] https://www.coolearth.org/ [2] https://www.givingwhatwecan.org/charity/cool-earth/

Trees are only sequestering the CO2, not removing it, so this seems like a bad solution at solving our removal of CO2. Also, for a densely populated area, where do you propose people go to plant said trees where they can survive without major care? What is the mortality rate of these trees over time considering weeds, water, bugs etc.

>"Trees are only sequestering the CO2, not removing it, so this seems like a bad solution at solving our removal of CO2"

I don't follow your logic here.

All of the atmospheric CO2 produced from fossil fuel combustion had been previously "sequestered" in the form of petroleum-based hydrocarbons before it was burned by humans.

Why do you feel that extracting atmospheric CO2 by building polysaccharide chains (aka wood) via photosynthesis in trees would be worse than having left it in its prior hydrocarbon form if we had never burned it in the first place?

I'd guess he's worried about the wood rotting, and the decay process venting CO2 (and, worse, methane) back into the atmosphere.

>Why do you feel that...

As a dead tree decomposes the heterotrophic organisms eating it release a large amount of the stored carbon back into the atmosphere as CO2 as we heterotrophs are want to do. That's where a lot of people stop and give up.

What I think a lot of people forget is that plants naturally spread. If you plant a tree and it survives for 50 years, it's producing seedlings for up to 90% of it's lifetime. If even two seedlings can become trees you have removed the CO2 from the air rather permanently.

Trees do spread naturally. We're revegetating 10 acres of land with native plants and its amazing to see the spread every year.

But that's not relevant in a situation where you're planting them for an end result like sequestering carbon (e.g. a renewable pine plantation).

Then you obtain the land, plant the heck out of it with seedlings, then thin them out http://www.gfc.state.ga.us/resources/publications/PineThinni... at regular intervals. Way more bang for the buck than planting a few and hoping for natural propagation.

Interestingly, from the 1970s forward, a vast reforestation of North America has been taking place[1]. The problem is more in places like the Amazon rain forest that is being deforested and stripped at alarming and unsustainable rates.

1. http://news.nationalgeographic.com/news/2006/11/061113-fores...

Changing your default search engine to Ecosia[1] can help with this too. A portion of their ad revenue (used to be 20% gross - not sure what it is now) goes toward tree planting.

[1] https://www.ecosia.org/

I made a google sheet that calculated that planting trees along the state and interstate highways for 1/2 the state of MN would capture enough carbon annually (when minimum maturity of 30 adult trees per hectare) to offset the carbon footprint of the entire state.

https://docs.google.com/spreadsheets/d/1dA5_AMW6EJPDZv2fP-KO...

That's fascinating! I noticed your US tab just multiplies the MN output by 50. Can you do a detailed analysis of planting trees along roads all throughout US (or at least the 48 states)? Or is there missing data needed to do that calculation?

I want to do that. Many states do not have as good information about their highways available though.

Please let me know when/if you get the info you need.

Edit: Can you just use an estimate for the total distance of highways in the US?

Thanks for that, will donate. Here's a link to the charity itself. I'll take a look and make sure it's on the up and up when I'm home then either donate or sign up for recurring donations if possible.

https://donate.trees.org/charity/charity?cid=23832

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