If I read this correctly, this is mostly aimed at the smoke-stacks of fossil fuel plants. Great for reducing their harm before we phase them out, and valuable especially if it is cheap enough to actually be plausible. Cheap here matter more than perfect, since the problem of emitting CO2 from fossil fuel plants is better (but more slowly) solved by phasing out fossil fuel.
But how does this work for scrubbing CO2 from general atmosphere, is it anywhere close to an option? Once we have 'solved' the problem of no longer emitting CO2, we will almost certainly still have way more CO2 in the atmosphere than we want. Does this new scrubber material make it feasible to reduce the CO2 from the atmosphere, or will it be more economical to deal with the symptoms of high CO2 levels?
>Does this new scrubber material make it feasible to reduce the CO2 from the atmosphere, or will it be more economical to deal with the symptoms of high CO2 levels?
The low tech solution for scrubbing C02 from the atmosphere is to get more plants absorbing it and prevent the plant decomposition back to CO2 or even worse to methane. Some of the agricultural waste may be just buried in the fields helping to build the organic matter in the soil, but it would be hard to avoid any CH4 emissions doing it. Just check any landfill with buried organic matter and some sipping in water. One can try to use pyrolysis and get charcoal. This would not be 100% emissions free (CO, CO2, CH4 etc.).
The main problem with the above is that collecting wood/straw/etc. transporting and then processing it also requires energy, at least on land. Converting the millions of agro machines to run on batteries or hydrogen would not be carbon neutral either.
Supposedly if we fertilize patches of the oceans the dead algae will nicely sink to the bottom not to be release CO2 for centuries.
My favourite solution to this is to use some of the pyrolysis products as fuel - if you burn and release 20% of the carbon captured by the plants to power the process of burying the remaining 80% the process is still carbon negative overall, and you have a nice to use hydrocarbon fuel that can more-or-less slot into existing machinery.
The biggest problem is the scale of it - to make a significant dent in global co2 you need to be pyrolysing a lot of wood - getting towards entire-earth scale managed forests.
I also think that compared to some pie or at times mirror in the sky terra engineering projects "plants for the rescue" look more realistic at this point.
>The biggest problem is the scale of it - to make a significant dent in global co2 you need to be pyrolysing a lot of wood
The giant scale and use of land is one thing. But increasingly in many places the limiting factor be it for agriculture or forest or biomass plantations is water. While forests and vegetation have more than just a sponge effect, we should keep in mind that a scorched dry forest or a field burns easily.
One may look at it as +/- net zero (what burns was absorbed by the plants we planted), it may be safer to go for high biomass yielding plants we can cut preferably more than 1x a year. In the case of fire only the carbon absorbed in the last say half a year would be released. And nasty plants such as Arundo can re-sprout after the fire. Or in a case of a prolonged drought given the right equipment one can just cut it down and get rid of the danger.
Stupid idea of mine: can we start burying our paper rather than recyling it? It means every sheet of paper requires cutting down more trees, and hence putting more trees (indirectly) into the ground. If you then re-plant those trees you capture more carbon.
I presume the paper doesn't add enough to create soil and just rots.
>But paper is pretty effectively recycled and trees aren't the only input - transport, water, and heat at the plant.
Exactly.
Moreover 1ha of Arundo produces 20-50t or more dry mass per year packed in 100mx100m area. Granted, not harvested at 0% humidity, less dense than paper. Collecting 50t of recycled paper from the containers in the city probably needs more energy for transport.
This is actually the logic for just burying plastic: it doesn't degrade on any important timescale. Acts as a carbon sink, and keeps it out of everything. Winning all around.
Not if you got the plastic using fossil fuels and extra energy. Which is the case for most of the non-degradable plastic.
Add to it that we are nowhere close to replace various types of plastics with materials obtained from non-fossil fuels.
There isn't enough arable land and fresh water to meaningfully address climate change in the time necessary. Algae farming with sea water might be a good alternative if we could address disposing the the algae without emissions.
This is the critical flaw in betting mostly on trees to remove CO2 from the atmosphere.
To get to the now-unlikely target of +1.5°C by 2100, the need is on the order of 6 billion tons of CO2 to remove each year by 2050[1]. A mature tree can capture only around 22 kg a year[2], so removing 6 billion tons would require planting 270 billion trees each year. To get a sense of the magnitude of the effort, there are an estimated 3 trillion trees on Earth today; we'd need to plant just as many in only 11 years.
Better yet: you burn the plants for energy, then sequester the conveniently high concentration CO2 from the smokestack and do with it whatever you'd think would be smart to do when burning fossiles.
About the Science article: my quick skim stumbled over the word "regenerate", which tells me it's not about some material suggested for permanently binding the carbon, but about a tool to get from smokestack-level CO2 concentrations to even higher levels?
> The low tech solution for scrubbing C02 from the atmosphere is to get more plants absorbing it and prevent the plant decomposition back to CO2 or even worse to methane.
Bring back moors. Moors can sink a shitload of CO2 - and there have been a lot of moors de-watered over the last centuries to gather peat and agricultural land.
The downside is you have to convince or pay off a lot of farmers who have farmed the former moors for just about the same timeframe.
Yes, moors would help. I remember that during some floods in Europe one of the ideas floating around was to construct large polders which will be flooded as needed. No clue if catching up flood waters that would be enough to turn such polders into carbon sink.
There was some documentary about a German farmer keeping his grasslands in a moor-like state by rising the water table lowered by drainage. This did work well for him in the times of the draught but in general if I remember correctly it did lower his income.
Uh, the experiment log on that page is actually moderately encouraging. The lesson, particularly from the EIFEX experiment, appears to be that it works great provided there's adequate silica for diatoms. No reference to Russ George required.
Yes, it is called eutrophication and is a huge pollution problem. The dead algae that drops to the ocean floor get eaten by bacteria and through that depletes the oxygen, resulting in hypoxic dead ocean. No fish and no plants, which in turn kills biodiversity both in and outside the water.
Even if the goal was to store CO2 and we didn't care about anything else, the method has additional problems. With nothing living in dead zones except for algae, the methane gas produced by decomposing dead algaes has a high risk of rising to the surface.
The "ocean fertilization" referred to here is not with nutrients, but with iron [0]. Apparently there are glacial runoffs at Greenland which would just need to be transported to other areas of the ocean in order to capture massive amounts of CO2.
Yes and no. Meaning: depositing fertilizer close to the shore in shallow waters causes toxic algal blooms and suffocates everything. One needs deep, cold waters so the sinking organic matter is not decomposing rapidly.
And yes, if the winds blow the Saharan dust over large oceanic surfaces algae do grow in otherwise "desert" waters and some of the generated biomass does sink deep.
One aspect these iron fertilization experiments have ignored is albedo. Leaving any sequestration on the table, and just focussing on keeping the albedo of equatorial oceans low for as long as possible has the real potential to avoid absorbing massive amounts of solar heat into the system. That doesn't solve the co2 problem, but because you can negate the feedback loop aspect of the problem, and perhaps even make natural sequestration occur faster if you lower temperature enough. One thing I haven't been able to figure out from the data from the experiments, is how long these blooms last. The tonnage of fertilizer and the size of the bloom, yes. Also, the experiments were done in eddies mostly to isolate the effects. So an open equatorial ocean experiment would be needed. Along with better local temperature monitoring. Some satellite imagery to verify albedo would be a plus. As far as ballpark numbers, if the bloom stays equatorial, you would need about 1.5e9 USD per however long a bloom lasts in order to maintain an albedo that would initiate snowball. That is scaling linearly up from the area affected by previous experiments vs their costs.
From German Wikipedia the albedo of water changes a lot with the angle. Oceans already are "dark" when hit by sunlight at +45degs angles. So it may not be that important.
Good question. I was also suspicious of the angle/framing of the paper as a smokestack capture solution. My thoughts are
1. smokestacks are a great place to start, it's thermodynamically easier, has low-hanging fruit, and can be a stepping stone to a atmospheric DAC solution.
2. I bet that the smokestack angle of the paper is due to ALF being a decent oxygen absorber. The paper made the argument that the CO2 (diameter 330pm) vs. N2 (diameter 364pm) selectivity was due to size exclusion principles. But oxygen has diameter 346pm, much closer to CO2, so it would stand to reason that oxygen would compete for CO2 binding efficiency. If you read the supplementary materials/experimental conditions, literally every experiment is done under a protective flow of 99.95% N2 gas, indicating that this compound is not to be exposed to air.
Even if this only works in smokestacks, it is hugely valuable. We will be stuck with some fossil fuel in the coming few years at least. Making those years less polluting is worthwhile.
I suppose there is a risk that people say "we can do fossil fuel a bit longer, we scrub it now", but I think that will pretty soon be a clearly untenable position.
> Cheap here matter more than perfect, since the problem of emitting CO2 from fossil fuel plants is better (but more slowly) solved by phasing out fossil fuel.
The goal is to stop emitting CO2, not phasing out fossil fuels. If you can use fossil fuel without emitting CO2 (and other greenhouse gasses), then the goal is achieved.
But we also know that fossil fuels are finite and it might be worthwhile to stop using them and learn to use alternatives before we get forced to do it when the sources run dry.
For me the most tragic part of the current situation is that if we somehow destroyed our current civilisation, there would be no raw resources to support a new industrial age.
I don't think there are (economical) ways to stop emitting CO2 without phasing out fossil fuels. And like you said, regardless of CO2, fossil fuels will run out anyway.
I wonder if any new civilization could bootstrap off existing knowledge and artifacts about electricity. Wind and water based electricity don't require stupidly complicated tech to get going. You can probably mine copper from ruins rather than mines. Similarly, perhaps current stores of coal and oil could also support some systems for long enough? Heck, I could even imagine old oil wells to be 'easy' to re-open.
In any case, neither I nor my children will be around after we destroy civilization. So I care much more about avoiding the destruction than the ability to rebuild afterwards.
If we somehow destroy our current civilization, then world population will plummet from starvation, especially in the third world that isn't fertilizer-self-sufficient.
And we'll still have plenty of raw coal + recyclable metals.
We won't have any raw coal. All raw coal is hundreds of meters below ground because everything that was easily accessible was already dug.
In my country hundreds of years ago people were gathering coal lying on the ground or picking it with a shovel in small holes. When oil was first found it was basically pooling on the surface or required a very shallow hole, nothing more than a deep water well, to reach.
Not only those, but a lot of other easily available sources have already been completely used up. There might be some that are overlooked in very sparsely populated, hard to reach places like Russia, Brazil or Antarctica. But the same reason why they have not been found and exploited would be why a new attempt at civilisation will also have hard time trying to find it.
Scrubbing C02 is important for industrial processes other than energy production so it’s very important to get it right otherwise we can’t fabricate stuff without increasing emissions and building renewable infrastructure while adding another 3.5b people to the population is going to involve a lot of fabrication.
The article states that the major advantage of this new material is much better resistance to water. Are you saying that the levels of water described in the paper are still way below untreated flue gasses?
I don't know. I just saw the word "dried" and mentioned it. Flu gasses are majority water. Natural gas has twice as much water and co2 (by moles), and according to another poster they even inject additional water.
For starters, humanity emits more CO2 than the combined mass of entire biosphere (every living organism, not just trees), every 10 years. Even if we were somehow able to cover all landmasses of Earth with trees (which we can't) and thus double/triple the biomass we would only set back the problem by a decade or two.
Second, trees are part of a cycle. They store the CO2 temporarily, then release it mostly back to the atmosphere -- very small part becomes soil.
Trees are not a magical solution that is somehow constantly sequestering CO2 from atmosphere. Trees store a bit of CO2 once and then it stops and can even easily be reversed (if you burn it down). New growth is necessary to keep the store at the same level, otherwise the trees will burn or die and CO2 is returned to the atmosphere.
It is actually very simple. Everybody can check easily. You do not have to believe me.
You need two numbers:
1. Amount of carbon emitted by humanity. The easiest way to get this is to find all production of coal, nat gas and oil and convert it to carbon.
2. Amount of carbon in biomass. You can find the estimate of weight of Earth's biomass online. Then you need to multiply by a factor of how much carbon there is in biomatter on average.
All necessary numbers are readily available and not controversial.
As to how much plants use CO2 it is IRRELEVANT. The only way it would be relevant is if you also had a number on how much plants emit CO2 back to atmosphere when they burn or rot. But this is extremely difficult to measure directly.
Just as you can't figure out how much you are saving up just based on your income without knowing your expenses.
But you do not have to estimate any of the two numbers. It is enough to imagine that, given constant weight of the biomass, all carbon converted from CO2 to biomass has also roughly equivalent release back to atmosphere one way or another.
But how does this work for scrubbing CO2 from general atmosphere, is it anywhere close to an option? Once we have 'solved' the problem of no longer emitting CO2, we will almost certainly still have way more CO2 in the atmosphere than we want. Does this new scrubber material make it feasible to reduce the CO2 from the atmosphere, or will it be more economical to deal with the symptoms of high CO2 levels?