Restoring natural forests is the best way to remove atmospheric carbon • Hacker News Board

Re: Restoring natural forests is the best way to remove atmospheric carbon

#41

Post by yellowapple » Tue, Apr 02, 2019, 8:47 PM UTC

Why natural forests? Would it not be more effective to focus on the plants/trees that consume the most atmospheric carbon?

There are certainly ecological arguments for natural forests v. artificial carbon-sequestration-optimized forests, but if maximum carbon sequestration is the goal, then the rational answer is to focus on those plants which sequester relatively large amounts of carbon instead of waiting for maybe a natural forest of not-necessarily-optimal plants to maybe grow on its own.

Also, last I checked, algae is still Earth's primary oxygen producer (and therefore implicitly the primary atmospheric carbon scrubber).

Re: Restoring natural forests is the best way to remove atmospheric carbon

#42

Post by jrace » Tue, Apr 02, 2019, 9:08 PM UTC

umvi wrote: post #36

lifehacked wrote: post #32

Let's not forget the oceanic ecosystems they also remove co2, all 3 should be mentioned all the time.

Build buildings out of wood -> Plant more trees -> build more buildings out of wood -> plant more trees, etc. This can sequester a lot of carbon over time, especially if said wood buildings are in places trees can't easily grow.

Cutting down trees can cause a release of stored carbon dioxide.

Structures composed of wood do not remove carbon dioxide from the atmosphere.

When old trees are cu down they should be replaced with new ones

Re: Restoring natural forests is the best way to remove atmospheric carbon

#43

Post by dahfizz » Tue, Apr 02, 2019, 9:17 PM UTC

seveneightn9ne wrote: post #39

EGreg wrote: post #28

Earlier quoted context omitted.

Exactly! Not to mention that reversing desertification and deforestation need to be done anyway. The Amazon rainforest is producing 20% of the world’s oxygen. Why not focus on that, Bolsonaro? But how can we get the world to change its focus? This is the biggest contributor to CO2 pollution: https://www.nationalgeographic.com/environment/global-warmin...

Hm, I'd heard the Amazon consumes at least as much O2 as it produces; it's basically in equilibrium. Unfortunately I don't remember the source but it was something like Planet Earth. I found a lot of sources quoting your 20% number, but it seems like that's not net produced O2 but rather gross. I'd be interested if anyone can find a source that says either way about the net O2/CO2 of the Amazon.

With absolutely no expertise in the subject, I would expect any sufficiently large land area to have no net oxygen production. It's not like oxygen levels fluctuate wildly, and it seems unlikely to have such a uniform O2 level on Earth if it's coming from just a few big producers.

Re: Restoring natural forests is the best way to remove atmospheric carbon

#44

Post by umvi » Tue, Apr 02, 2019, 9:22 PM UTC

jrace wrote: post #42

umvi wrote: post #36

Earlier quoted context omitted.

Build buildings out of wood -> Plant more trees -> build more buildings out of wood -> plant more trees, etc. This can sequester a lot of carbon over time, especially if said wood buildings are in places trees can't easily grow.

Cutting down trees can cause a release of stored carbon dioxide. Structures composed of wood do not remove carbon dioxide from the atmosphere. When old trees are cu down they should be replaced with new ones

> Structures composed of wood do not remove carbon dioxide from the atmosphere.

Why not? Just some napkin math here but:

Say you have three 10K kg trees. Wood is ~50% carbon, so that means they collectively contain around 15K kg of carbon. Cut them down and turn them into framing lumber and build a house. You now have a house frame with roughly 15K kg of carbon.

Now plant 3 trees where the old ones were. Once grown you have now collectively sequestered 30K kg of carbon - half of it is in the trees themselves, half in the house.

Keep doing that. After a decade you now you have 1000 houses that have each sequestered 15K kg of carbon from the atmosphere, or 15M kg of carbon.

Re: Restoring natural forests is the best way to remove atmospheric carbon

#45

Post by Pfhreak » Tue, Apr 02, 2019, 9:27 PM UTC

umvi wrote: post #44

jrace wrote: post #42

Earlier quoted context omitted.

Cutting down trees can cause a release of stored carbon dioxide. Structures composed of wood do not remove carbon dioxide from the atmosphere. When old trees are cu down they should be replaced with new ones

> Structures composed of wood do not remove carbon dioxide from the atmosphere. Why not? Just some napkin math here but: Say you have three 10K kg trees. Wood is ~50% carbon, so that means they collectively contain around 15K kg of carbon. Cut them down and turn them into framing lumber and build a house. You now have a house frame with roughly 15K kg of carbon. Now plant 3 trees where the old ones were. Once grown y…

I think you might be holding a spherical cow.

Does your math include the carbon necessary to harvest, transport, cut the lumber? And to haul away the existing structure?

Re: Restoring natural forests is the best way to remove atmospheric carbon

#46

Post by dragonwriter » Tue, Apr 02, 2019, 9:28 PM UTC

umvi wrote: post #44

jrace wrote: post #42

Earlier quoted context omitted.

Cutting down trees can cause a release of stored carbon dioxide. Structures composed of wood do not remove carbon dioxide from the atmosphere. When old trees are cu down they should be replaced with new ones

> Structures composed of wood do not remove carbon dioxide from the atmosphere. Why not? Just some napkin math here but: Say you have three 10K kg trees. Wood is ~50% carbon, so that means they collectively contain around 15K kg of carbon. Cut them down and turn them into framing lumber and build a house. You now have a house frame with roughly 15K kg of carbon. Now plant 3 trees where the old ones were. Once grown y…

> > Structures composed of wood do not remove carbon dioxide from the atmosphere. Why not?

> Why not?

On average, does wood in structures release carbon through decay, fire, etc., faster or slower than if the wood was left in a living tree? Intuitively, I don't see any reason to expect effective sequestration.

Your analysis seems to suppose that if wood was not used to make a structure, the trees would instantly release their carbon and not be replaced, rather than continuing to grow.

Re: Restoring natural forests is the best way to remove atmospheric carbon

#47

Post by umvi » Tue, Apr 02, 2019, 9:34 PM UTC

Pfhreak wrote: post #45

umvi wrote: post #44

Earlier quoted context omitted.

> Structures composed of wood do not remove carbon dioxide from the atmosphere. Why not? Just some napkin math here but: Say you have three 10K kg trees. Wood is ~50% carbon, so that means they collectively contain around 15K kg of carbon. Cut them down and turn them into framing lumber and build a house. You now have a house frame with roughly 15K kg of carbon. Now plant 3 trees where the old ones were. Once grown y…

I think you might be holding a spherical cow. Does your math include the carbon necessary to harvest, transport, cut the lumber? And to haul away the existing structure?

> Does your math include the carbon necessary to harvest, transport, cut the lumber? And to haul away the existing structure?

True. I don't know how many lbs of carbon it takes to cut down, transport, and harvest a tree. But I would hope less than 15,000 kg.

If the trade off isn't worth it, use electric machinery and transportation powered by nuclear plants.

Re: Restoring natural forests is the best way to remove atmospheric carbon

#48

Post by umvi » Tue, Apr 02, 2019, 9:42 PM UTC

dragonwriter wrote: post #46

umvi wrote: post #44

Earlier quoted context omitted.

> Structures composed of wood do not remove carbon dioxide from the atmosphere. Why not? Just some napkin math here but: Say you have three 10K kg trees. Wood is ~50% carbon, so that means they collectively contain around 15K kg of carbon. Cut them down and turn them into framing lumber and build a house. You now have a house frame with roughly 15K kg of carbon. Now plant 3 trees where the old ones were. Once grown y…

> > Structures composed of wood do not remove carbon dioxide from the atmosphere. Why not? > Why not? On average, does wood in structures release carbon through decay, fire, etc., faster or slower than if the wood was left in a living tree? Intuitively, I don't see any reason to expect effective sequestration. Your analysis seems to suppose that if wood was not used to make a structure, the trees would instantly rele…

> On average, does wood in structures release carbon through decay, fire, etc., faster or slower than if the wood was left in a living tree?

Trees don't grow at the same rate forever. They sprout up quickly and rapidly sequester carbon until they reach maturity, at which point there are diminishing returns in terms of carbon sequestration.

Treated wood is much more resistant to decay and fire than untreated wood.

> Your analysis seems to suppose that if wood was not used to make a structure, the trees would instantly release their carbon and not be replaced, rather than continuing to grow.

No, I'm saying that a mature tree sequesters carbon much more slowly than growing trees. Think about it. It's the same for animals. Babies grow like crazy and gain mass at an amazing rate. Adults... don't. I've been 150 lbs for the past 10 years. My son, however, was 6 lbs 2 years ago, 20 lbs last year, and 40 lbs this year. That means his body is locking away 20 lbs worth of matter per year.

Take a mature tree, turn it in to a building. Grow another mature tree in its spot and you've now sequestered effectively twice as much as having never turned the tree into a building. That's what I'm suggesting.

Re: Restoring natural forests is the best way to remove atmospheric carbon

#49

Post by cgh » Tue, Apr 02, 2019, 9:50 PM UTC

umvi wrote: post #9

I think part of this, at least, it eating meat much more sparingly. From what I understand huge swaths of the Amazon are slashed and burned to make room for cattle which do the opposite of sequestering carbon by converting any it finds into methane (and meat). So basically we need to eat less meat to give plants more room. And we will need lots of room since we need to not only sequester the carbon of the trees we've…

In the US, beef production accounts for about 2.6% of GHG emissions. Most beef eaten in North America was raised there. If you are from these regions, reducing meat consumption won't help the Amazon or much else.

Note that the issues with clearing the forests of the Amazon for beef won't end if beef production is banned or whatever. Those people still need to do something, which is why forest clearing for soy production is on the rise.

Re: Restoring natural forests is the best way to remove atmospheric carbon

#50

Post by b_tterc_p » Tue, Apr 02, 2019, 9:54 PM UTC

weepingprophet wrote: post #26

Every time an article on this topic comes up, I read the same responses in the comments, here or on Reddit. Yes, it's cheaper not to emit than it is to reclaim, but how does this comment contribute to the solution? Even if everybody stopped emitting CO2 today, we still need to remove many Gigatons of CO2 from the atmosphere to save the planet. Planting trees is cheap and is PART of the solution. Similarly, every time…

Is this true? This is something I question a lot. Intuition tells me that the greenhouse effect of CO2 and other gasses determines derivative of climate change, but its often presented like it sets the absolute average temperature.

That is, if we stopped producing CO2 completely back to pre-industrial levels (somehow), would we expect the globe to get warmer? Or are both statements true because excess CO2 naturally leaves the atmosphere into space + gets absorbed into the ocean?