Restoring natural forests is the best way to remove atmospheric carbon
nature.com
nature.com
This is the biggest contributor to CO2 pollution:
https://www.nationalgeographic.com/environment/global-warmin...
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.
Chemistry is incredibly simple when you are only interested in the general inputs and outputs of a black box system.
And the burning of the forest is increasing a lot in Bolsonaro's government. Well, it is increasing a lot since the president DiLma was ousted.
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 an article about direct air capture (DAC) comes up, somebody complains that we should be planting trees instead. This is ALSO a very unhelpful comment, because in truth we need to be doing both DAC and planting trees. Even if we reforested all the depleted forests of the world, there would still be gigatons of CO2 to remove.
The answer to every proposed solution to climate change is not whether "this or that", it is "this AND that". We need to be doing everything: reforest, DAC, wind, solar, nuclear, synthetic meats, etc. The whole kit.
While I think it is terrible it might be an additional great sink for CO2.
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?
Then even if you get rid of the carbon, the temperature stays higher because the ice is gone and is no longer reflecting light back into space. And the ice is from the last ice age, it doesn't just refreeze on its own -- especially now that the temperature is higher.
Meanwhile with higher temperatures there are more areas of drought, which means less vegetation grows there, which means those areas can absorb less carbon. And that too is sticky. If the temperature stays higher then there continue to be droughts and less vegetation.
What this means is that we need to stop emitting carbon ASAP, and then on top of that ultimately do something to reverse the effects and actively work to get the temperature back down to where it was, because it may not be able to fix itself.
We think of the Earth as a self-regulating system, but that isn't because it's stable, it's because it's adaptive. Earth's temperatures have been higher than this and still sustained life, but none of that life was humans, and the previous changes were accompanied by mass extinctions.
Check the historical data on CO₂ levels from antarctic ice. It correlates perfectly with the ice ages (we had samples of ~400K years covering 3 previous), and guess what, we are now on the brink of a next one.
Furthermore, it's affordable: $15/average US resident/year. I wrote a blog post about it recently:
https://automicrofarm.com/blog/2019/03/solving-climate-chang...
The linked, peer-reviewed paper in Nature says otherwise.
Perhaps you could review it and point out their mistake?
Perhaps you could track down the discrepancy in the statements?
So no, while this might work to pacify the conscience of an individual, it makes absolutely no sense to do it at scale.
Also, for ten years, 327 million Americans each planting 1.5k trees comes out to half a trillion trees. The link in my blog says there is room for 1.2 trillion trees to be planted, so the math works out.
Also, there are many situations where a net-negative amount of carbon could be released into the atmosphere: the tree could be used as lumber to build something, thus not decomposing. Or it could be partially or fully buried, sequestering some or most of the carbon in the soil.
More importantly, the actual lumber consumption is trivial. America consumes half of a single tree per capita annually[1]. Even if you assume that this half of a single tree gets sequestered permanently (which is not realistic), that’s a far, far cry from 150 trees yearly.
Really, this is all so silly: if you can grow so much biomass to offset all carbon emissions, why wouldn’t you burn that biomass instead of burning fossils and burying the biomass? It makes no sense, like most of the feel-good green plans.
Also, if a tree dies, it frees up space for another tree. So in effect, as long as you keep those 1.2T trees growing (and replace any dead ones promptly), you will keep that carbon sequestered.
> Really, this is all so silly... It makes no sense, like most of the feel-good green plans.
At this point, it seems like you're just dismissing the idea. Feel free to do so, but you haven't provided any reason why it won't work.
This is true on average in otherwise equivalent conditions, sure.
Because a solution that can only possibly delay the climate change by a decade or two with extreme change to global ecosystems by immense program of forestation is no solution at all. Seriously, what’s the point of doing this, if it require extreme global efforts, and will only make marginal difference? It is much more cost efficient to simply replace emissions with (also rather inefficient) solar and wind, not to mention nuclear power, instead of offsetting them by planting trees, which has no chance of having any effect other than delaying the climate change by a few decades theoretically, and a few years in practice.
The question rather is, why are you so hung up on the idea of planting trees, if it’s not going to make any difference?
> Also, if a tree dies, it frees up space for another tree. So in effect, as long as you keep those 1.2T trees growing (and replace any dead ones promptly), you will keep that carbon sequestered.
Indeed, these 1.2T live trees will sequester the carbon. I do not question that. What I question is the point of doing that if you keep emitting carbon: this will only delay the climate change by a few years, because after you use up all available space and grow these 1.2T trees to maturity, you won’t be able to capture any extra carbon: all carbon captured by the trees will be offset by the carbon emitted by decaying dead trees (or huge forest fires, which are inevitable if you don’t remove fuel from these huge foerests), unless of course you bury them.
> Feel free to do so, but you haven't provided any reason why it won't work.
No, I did, you’re just ignoring it. Again, to recapitulate: planting trees will not offset carbon dioxide emissions unless you take on extreme effort to bury these immense amounts of lumber (which would also be stupid if you keep removing more fossils from the ground and burning them). Planting trees will only delay these emissions, by the length of time that is relatively trivial compared to extreme effort necessary, and insane amounts of ecosystems destroyed. Planting 1.2T trees would destroy so many ecosystems that it would be more ecological to simply do nothing.
Planting trees to offset carbon dioxide emissions from fossils is like putting a yoghurt cup under leaking drain pipe. It will work for a while, until the cup overflows, at which point you’re back to square one. You can then replace cup and pour out water in some other drain (that is, bury the lumber), but that’s stupid, because the whole point of a drain is to pour waste water into it, and if it is leaking, you should fix the leak instead of using some silly cup-to-other-drain scheme. Similarly, planting trees will only delay the inevitable, and when the cup overflows, that is, the tree dies, you need to figure out some other way to sequester the dead tree.
> Indeed, these 1.2T live trees will sequester the carbon. I do not question that.
It seems we agree that as long as these 1.2T trees are living (and any ones that die are replaced), the carbon will be sequestered. As long as humanity can keep on doing that, the delay will be... indefinite. Are we in agreement on that point?
With the leaky pipe analogy, it seems you are worried we'll run out of room to put dead trees. Indeed, burying them is a great idea, and that can be combined with Hügelkultur technique to produce better growing conditions for other plants, including... more trees.
As far as some of the other concerns you raise: the Trees.org organization can have a tree planted for $0.10 (by people who are happy to plant it and take care of it). By that measure, it seems this method is the least expensive (if we judge effort by the amount it costs) and least extreme of all. Will Trees.org be able to scale to 1.2T trees? It's hard to say. They've planted 155M trees so far, so they need to scale by a factor of ~10000x. It will certainly be hard, but it seems to be possible: we have room for them in places where trees previously grew (see the link to the study where the 1.2T number comes from). Recently, India planted 50M trees in one day; a startup has a goal to plant 500B trees by 2050 (if they have two equally-capable competitors, the 1.2T quota can be met before then).
What ecosystems will be destroyed by planting trees? Currently deforested areas? That seems hard to believe.
I view any carbon sequestration efforts to be a partial stop-gap effort until the world becomes mostly electrified and using renewable/nuclear energy. I am for all kinds of carbon sequestration efforts, but as a consumer, I would like them to be relatively inexpensive, and not have an unknown side effect. Planting trees meet both these requirements.
Yes, as long as there’s a cup under leaking pipe, the amount of leak equivalent to the volume of the cup is sequestered. When the cup is full and starts overflowing (I.e. your trees start to die) you have to figure out where to contain the overflow. If you do nothing, it will simply spill on the floor (I.e. dying trees will decompose), which puts you back on the square one.
> With the leaky pipe analogy, it seems you are worried we'll run out of room to put dead trees. Indeed, burying them is a great idea, and that can be combined with Hügelkultur technique to produce better growing conditions for other plants, including... more trees.
Somewhat, but not quite. The real concerns is that burying trees while you keep extracting fossils is absolutely bonkers idea.
Burying trees would make sense (though not necessarily be most cost effective way to do so) in the future world where we no longer extract fossils. Then, growing trees and burying them would (extremely slowly, and at a huge ecological cost) bring us back to previous CO2 level before industrial revolution. If you keep extracting coal from the ground, however, burying trees is insanely stupid and wasteful thing to do, because it would be offsetting the fossil emissions by literally putting the fossils back into the ground. Why go through all the motions with planting trillions of trees, if you could simply not extract the fossils in the first place?
> I view any carbon sequestration efforts to be a partial stop-gap effort until the world becomes mostly electrified and using renewable/nuclear energy.
Look, if you don’t bury trees, all you do is introduce slight delay in the system. If you want to use the trees as a stop gap, then it makes much more sense to use the trees as a biomass, that is, burn them instead. That way, you’ll actually in fact be carbon-neutral.
Even when it finally decomposes through rot or consumption a lot of the carbon is kept out of the atmosphere, ending up in the food chain fed by the organisms that consume it.
Plant a tree now, in 200 years it may be part of your great great great grandchildren.
No, not a lot. In fact, it’s practically nothing, compared to the mass of trees. Think about it: are you using the mass of 150 adult trees annually for buildings? Are you sequestering much of it in your body? Not even close. Today America consumes less than a half of a single adult tree per capita per year.
The carbon is only sequestered when the trees are alive or when they are buried or sunk. If you don’t bury and only have space for a decade of tree planting, you are at best going to delay the climate change by a decade, which is not nothing, but won’t change much. And, of course, we ignore things like albedo changes due to more forestation which could offset a big part of gain.
Also, as long as you replace any trees that die with seedlings, you don't need to worry about what happens to the dead wood.
This method comes out to a cost of $6.70/ton sequestered. Other methods can cost many multiples of this amount. Do you have any estimates for iron seeding of the equatorial Pacific?
> Also, as long as you replace any trees that die with seedlings, you don't need to worry about what happens to the dead wood.
You do, though. If the wood decomposes, all the CO2 is released back to atmosphere, which puts you back at square one.
https://www.cbc.ca/news/canada/calgary/canada-forests-carbon...
""That's because trees don't just absorb carbon when they grow, they emit it when they die and decompose, or burn.
When you add up both the absorption and emission, Canada's forests haven't been a net carbon sink since 2001. Due largely to forest fires and insect infestations, the trees have actually added to our country's greenhouse gas emissions for each of the past 15 years on record.""
Also, something not mentioned in the article (but added by a botanist friend), conifers in general apparently produce much more volatile oils, so are more susceptible to flames/ignition/burning.
https://www.livescience.com/46958-trees-ozone-pollution-map....
(*not the same as smog, you need NOx emissions as well for that to form)
What I've been hearing is that one of the problems with Canada's "managed" forests is the reduction (in BC, at least) of deciduous trees which apparently can act as firebreaks [1]. BC (and the pacific northwest in general) has seen a steady increase in the length and damage caused by the fire season. It is April and we are already battling large fires in the province.
[1] https://www.cbc.ca/news/canada/british-columbia/it-blows-my-...
An aggressive reclamation project of desert could both work towards progress in carbon recapture and add valuable natural resources to poor countries.
https://en.m.wikipedia.org/wiki/Sahara_Forest_Project
Have you heard of the great green wall or the Sahara forest project?
Accelerated weathering is our first best hope of lowering CO2 in the atmosphere.
Weathering is the conversion of carbonates and CO2 to form bicarbonates.
Grinding and aerosolizing limestone and other similar minerals hasn’t been tried very much.
Unlike with anything plant-based, once CO2 goes through this reaction, it stays.
In a few billion years, it’ll cause the extinction of life on Earth, but that’s a problem we can take our time to figure out.
http://www.geoengineering.ox.ac.uk/www.geoengineering.ox.ac....
If you really want to add high-tech, then use drones
https://www.fastcompany.com/40450262/these-tree-planting-dro...
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
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.
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.
> 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.
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.
It takes several (in many cases 5+) decades for a tree to mature (in the sense of growth levelling off.) The average proportion of original wood building remaining after 50 years is, well, less than 100%.
Probably significantly, more than if the old tree died and fell, so you could have some net gain, but it's not going to be 100%. (And its going to be even less if you are clearing land for the building.)
Some key points are:
1. Forests reach their maximum level of carbon sequestration after around 70 years. After this point, they are no longer a net carbon sink.
2. If you periodically cut down the trees, turn the wood into long-lived products (like buildings), and then replant, you can sequester more carbon.
3. Exactly how much more depends on assumptions about the length of the useful life of a building and what is done with the wood after the building reaches the end of its useful life.
4. If you're looking at net carbon emissions, you also need to consider substitution -- by using wood in a building, you're decreasing the need for other building materials like concrete and steel, which emit a lot of CO2 in their production. They model various scenarios on the paper.
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).
If you sit down and study which types of plants sequester the most carbon, and plant a forest comprised entirely of that species, you run into a few problems:
First, parasites tend to be much worse. Whichever parasite prefers that particular type of plant will have an enormous food supply and a subsequent population explosion, with dire consequences for the entire forest. As the plants die, they will release the carbon they've stored.
Second, different plants prioritize pulling different resources out of the ground. There isn't a simple recipe of ax carbon dioxide, bx water, cx nitrogen, dx phosphorus etc = x kg carbon sequestered. Some species need more nitrogen, some need more phosphorus, some need more water etc. Different areas of the soil will have different concentrations of each resource the plants need. By having a diverse population, you will better utilize the soil's diverse resources.
https://phys.org/news/2018-10-species-rich-forests-carbon-mo... DOI: 10.1126/science.aat6405
In the study, the monocultures they studied included monocultures of bamboo and eucalyptus, which are extremely productive monocultures. These plots were still less productive than diverse forests.
You're correct about algae scrubbing carbon faster than forests, however algae to do not sequester appreciable amounts of carbon. It's released back into the environment nearly as quickly as it is removed. Trees, on the other hand, sequester lots of carbon in their trunks and root systems, so they are an important consideration with regards to anthropogenic climate change.
Re: soil diversity, by all means pick plants/trees that are suited to that soil, as long as they are especially effective at trapping carbon.
Fair point about algae.
Its irrational to continue to neglect natural systems in a world where their capacities to sustain diversity have been overloaded by anthropological targets.
I'm not sure I understand... To me, the only question is, how much CO2 we store per km2 (which might be a higher number for a natural forest). The plantation being cut down and then regrown has 0 net impact, just like trees dying and new trees growing in a forest. The plantation being cut down and not regrown has the same negative (+CO2) impact as the forest eventually being burned/cut down.
Seems a lot like that would turn atmospheric carbon into a building material.
That carbon will go back to co2 again if the wood rots or burns - but not when it dries.
So, if you subscribe to a dead-tree newspaper, it might be better for the atmosphere to throw away the paper instead of recycling it.
That's logically equivalent to saying your car won't run out of gas because on balance there's always exactly as much fuel going in as being burned. It's missing the point.
The issue here is that a farm "stores" very little carbon, as most of it gets re-released at the end of the season when the crops are harvested and decomposed in some way back into atmospheric carbon. A forest, on the other hand, continues growing for decades as a net carbon sink. All the carbon it absorbs stays in the forsest as biomass (and metabiomass stuff like peat and logs and soil).
A mature forest, effectively, has a much larger "tank" for the carbon that doesn't involve storing it in the atmosphere, where we don't want it. Farms don't.
Yes, that's correct - that plantation, in itself, has zero net loss of carbon once it regrows.
What you're missing is the activity in the meantime that contributes carbon to other cycles of carbon heat trapping.
So when all is said and done, sure, that forest is back where it was with the same amount of carbon - but the permafrost it helped melt (with accompanying release of methane) is still melted.
If at every moment someone is selling a stock, someone else is buying it, this argument would say the stock is worth zero. Because for every person trying to buy it for X someone is “buying it” for -X.
But of course, X is what matters. That’s how we calculate market cap and it measures overall effects
Selling “it” for X is not buying “it” for -X. It's buying X for “it”.
More specifically, if A sells X to B for Y, A gives up X for Y implying Y is worth at least X to A (and X at most Y), While B gives up Y for X, implying that X is worth at least Y to B (and Y at most X.)
Hence, that trade occuring in market where X and Y have access to all potential purchasers and sellers of X and Y fixes the value of X equal to Y.
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 previously destroyed (assuming they were burned and not converted into buildings), but all the millions (billions?) (trillions?) of pounds of hydrocarbons we've pumped out of the ground.
To sequester that much carbon we need trillions of pounds more life on earth than we currently have which means we need to let the oceans fill up with carbon-based mass (algae, fish, etc), let the rain forests and other carbon-high forests grow to their geographic boundaries.
I don't think it's the silver bullet, but it's definitely a great start and technologically easier than turning CO2 into graphene or diamonds or whatever.
Eating less meat gets mentioned whenever a climate change debate appears here. Perhaps my own position as a meat eater makes react somewhat critically to this (when I was a vegetarian, I had trouble with my digestion that eating meat seemed to solve).
With that caveat, I should say that even if producing less meat was a good solution to climate change, individual abstention seems unlikely to be a path that's going to get us very far towards this change. One can see various social movements against a variety of products which don't by themselves prevent the production of these products. Whichever actions one might describe in a "ten things one can do to save the planet" list, those actions will done by a limited number of people, determined by sociological factors. Moreover, reduce the demand for X environmentally product from group Y and you decrease the price, stimulating demand from group Z.
More concretely, I have friends are homeless and nearly homeless. Eating less meat might be healthier and less environmentally destructive but these people aren't going to make that choice because their choices and values revolve around what lets them survive. And broadly, if producers of a product can't sell to one group, they can find another group.
My claim is that any shift in agricultural CO2 production is going to require regulation, whatever choices some consumers might make just won't change things and to various extents, acting as if these choices are a program does more harm than good.
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.
It's cheaper to not emit 1T of CO2, then to pull 1T of CO2 out of the air.
You can't stop entropy - but you slow it down.
Optimize the critical path. When your patient is bleeding from a severed arm, don't waste time with slapping a bandaid on their little toe.
It's tragic that everyone is going to pay more because humans couldn't coordinate soon enough to just do the smart thing, but that's how it is. The IPCC is discussing negative emissions strategies not because they're cheaper than cutting emissions but because humans are not implementing deep emissions cuts fast enough.
There's a lot of (relatively) low-hanging fruit, like making transport more efficient and eating less meat.