Independent of Anthropogenic Global Warming assume we want to reduce the CO2 by 100 ppm. That would take the concentration in the atmosphere back to what it was in 1965. According to Wikipedia, “Each part per million by volume of CO2 in the atmosphere represents approximately 2.13 gigatonnes of carbon or 7.82 gigatonnes of CO2.”
For 100 ppm we would need to take 782 gigatonnes out of the air, 78 gigatonnes per year to get it done in ten years. Liquid CO2 is denser than water at 1.1 t/cubic meters. Or around 710 billion cubic meters or 710 cubic km of liquid CO2.
The first question that occurs to me is where do you put it? There have been a couple of events where CO2 boiled out of lakes and asphyxiated people. Lake Nyos disaster - Wikipedia A large CO2 blowout would be very rough on people downhill/downwind.
Despite the blowout problem, how about old oil fields? Oil consumption has run about 4 cubic km/year for the last 40 years. 160 cubic km of storage (less however much the formation has lost pore space) will run out in a couple of years so old oil fields will not be enough for storing CO2 though they could be used for a start.
As above, CO2 is denser than water and at modest depths, the pressure is high enough to keep it a liquid. So it is possible to store vast amounts in the ocean depths. This needs a more detailed analysis, not only of the CO2 dissolving in seawater but lighter non-polar methane dissolving into the CO2 and reducing the density. An ocean burp of a few hundred cubic km of CO2 would be a disaster.
Some people have talked about olivine. A ton of olivine (eventually) takes up a ton of CO2, so it would take mining and grinding up 78 billion tons per year. That’s a hard number to get a grasp on, around 10 tons per person for the whole population of the world every year for a decade. It’s also around 1000 times the mining of gravel in the US.
(I used to build computer interface equipment for a copper company that (at that time) ground about 22 million tons a year of hard rock to beach sand. It was an enormous operation. It would take somewhat over 3000 of these to mine and grind that much olivine.)
Just trying to put engineering numbers on the olivine proposal, not disparaging it. Olivine has a distinct advantage over pumping liquid CO2 into the ground because it will not blow out.
Carbon Capture & Storage is going to be very, very expensive. In a world of limited resources (and there is no other kind of world), that means a lot of hospitals, schools, roads, railways, ports, research facilities are not going to be built. To paraphrase global-warning believer Bjorn Lomborg – Is the cure going to be worse than the disease?
It is very difficult for any technical person to take the hypothesis of Catastrophic Anthropogenic Global Warming seriously. (We know there is no scientific hypothesis for Anthropogenic Climate Change). Geology tells us that the climate of Planet Earth has been varying continuously for as far back as we can probe – Ice Ages, the giant swamps of the Carboniferous Era, etc. We know that atmospheric CO2 has varied tremendously, and has often been much higher than in 1965. History tells us that human civilizations have done better during warmer periods than colder periods. What is the case for making immediate severe sacrifices when the benefits are so limited, and indeed unlikely?
The hypothesis of Catastrophic Anthropogenic Global Warming does not benefit from the scientific howlers from its proponents – such as when Algore claims that we need to remove ALL CO2 from the atmosphere. It is as if he had never heard of the Carbon Cycle!
I don’t find it difficult to take catastrophic warming seriously. And given my background, I think you would be hard-pressed to say that I am not a technical person. (Look at the Wikipedia page about me.)
However, for over 30 years I have been writing about the CO2 crisis of having too little in the atmosphere.
“. . . the real carbon dioxide crisis will come when there is too
little in the air because people are mining carbon (the strongest
engineering material) from the air to build houses, roads, tunnels through
the Earth’s mantle, industrial works, and spacecraft in large numbers.”
Fall '90 edition of Jim Baen’s New Destinies magazine
But this depends on nanotechnology or something close to it. We don’t have that yet. We might get it when Ray Kurzweil thinks it will happen (the mid-2040s) or we may never get it. To whatever extent the climate is affected by CO2 we may be facing big problems. It doesn’t take much climate disruption to muck up worldwide farming–look up what happened in 536. AAAS
The world has certainly seen times with a lot more CO2 in the atmosphere. But a huge number of humans didn’t live in those limes.
Re “very, very expensive” it seems possible to make money from capturing CO2 and selling synthetic fuel. It will require a factor of ten cost reduction for the capital equipment for making hydrogen though. (The energy is already cheap enough. More on this if anyone wants it.)
For the sake of demonstrating the magnitude of the task, this is a fine assumption, but I’m not sure why we’d want to do that. Suppose we could wave a magic wand and instantly reach net zero CO₂ added to the atmosphere. Then the level would freeze where it is at present, where there doesn’t appear to be any serious consequences for the climate compared to 1965. Indeed, some measures such as the number of intense hurricane landfalls, appear to have gotten better compared to times with lower CO₂.
According to the Wikipedia (yes, I know…) page on carbon dioxide removal (that’s removal from atmosphere with a mean concentration of CO₂ as opposed to “carbon capture and sequestration”, which are means of capturing the emissions of CO₂ from processes before it is released in the atmosphere, and serves only to slow the rise in atmospheric CO₂ levels), the least expensive (but slowest) way to remove carbon dioxide is by planting trees and upon harvest use them in ways which do not release their carbon back into the atmosphere (failing any productive use for excess trees, I suppose you could sink them into the abyssal plains of the oceans, which should keep the carbon out of circulation for a long time). The cost of afforestation for carbon capture is estimated around US$ 50/tonne of CO₂, so the cost of removing 7.82 gigatonnes to reduce the level by 100 ppm would be US$ 391 billion, which doesn’t sound like that much compared to estimates of things like the “Green New Deal”, whose cost has been estimated as in excess of US$ 50 trillion. But it would take decades, as trees don’t grow that fast and you’d have to find the land to plant them where they would grow without artificial irrigation.
Cost estimates for direct air capture (removal of CO₂ from ambient air) range from US$ 250 to US$ 600 per tonne, so the cost of removing 7.82 gigatonnes would be US$ 2 trillion, but that doesn’t include the cost, complexity, or hazards of sequestering the CO₂ captured, as discussed in the original post.
Come on! Are we seriously going to suggest that intelligent human beings would be unable to adjust to an atmospheric carbon dioxide climbing over (say) 50 generations to a level still less than 0.1% whereas dumb dinosaurs managed the transition without the benefit of brains?
Why do so many people want to hang their hats on technology which does not exist, or which requires orders of magnitude cost reductions by unknown means, instead of looking at the technology we have today which we know is feasible, economic, and can be further improved? Marion King Hubbert said it well all the way back in 1956 – nuclear fission will replace fossil fuels.
Because liquid hydrocarbons are the optimal known fuels for mobile power sources (like the equipment needed to erect windmills), we can use nuclear fission energy to make them. Manufacturing liquid fuels is also fairly old technology, as used by WWII Germany and apartheid-era South Africa. And that technology too can probably be significantly improved.
There is a reason that China and Russia are investing heavily in nuclear fission energy instead of following the West in seeking pots of gold at the end of rainbows!
But … wood floats! Human beings could certainly sink those trees – but that would require some method such as coating them in cement. And making cement would release CO2 into the atmosphere. Oh! The inhumanity!
Technical people love solving problems. Sometimes we need to ask ourselves if there really is a problem there to be solved.
If we do assume that we needed to remove 100 ppm of CO2 from the atmosphere, it does seem to be a very big problem. How then can we hope for huge numbers of humans to live somewhere besides earth?
My personal opinion is that the global warming proponents have seriously damaged their credibility. As a group they seem to have taken the same authoritarian approach that was taken on COVID. Try to silence debate. Make predictions that given time become obviously wrong. Attempt to use fear and marketing techniques to motivate the population. Allow profiteering.
Whether right or wrong global warming was easy to mock. Whenever there was a cold weather event, people would say “where is the global warming?”. Thus, it was rebranded to climate change. Now every weather event is evidence of climate change. Two years ago we had a climate scientist give a talk at the company I work. I only read the synopsis. Minnesota had been getting excess rainfall and this was due to climate change and it would continue. Presumably his talk explained all the negatives of this excess rainfall. Two years later and we have a draught.
It remains to be seen, but the US Dept of Agriculture predicted record corn yields this year. Obviously there are many factors to crop yield. Fertilizer, genetics and farming techniques, have all helped yields improve over the years. Freeman Dyson proposed that the planet was getting greener and that is was a good thing. I wonder if this is helping yields.
Wood floats on the surface of the ocean. But if you took it down to the deep ocean, the water and air components would be squeezed out and the density of the remaining material may be greater than that of water. I don’t know if this is the case, but it would be an easy experiment to run.
You could also bury them below the ocean bottom. We already have technology to bury trans-oceanic cables below the sea floor, so that could be adapted. But all this would apply only if some long-term use for the wood could not be found, such as building houses for the several billions of people who do not have adequate dwellings today and in the time over which the trees mature.
All of this is somewhat ironic, because one of the long-term scenarios for the Earth become uninhabitable is the Sun’s slowly increasing luminosity causing silicate minerals to weather faster, eventually (around 600 million years in the future) locking up enough carbon dioxide so plants can no longer perform photosynthesis.
Indeed! Human ingenuity could undoubtedly find many ways to sequester the carbon in dead trees. The issue is that all of those ways would involve using energy – and where would that energy come from? And what alternative uses of that energy (eg heart surgery, wastewater treatment) would we have to forego in order to sequester the dead trees?
As you point out, atmospheric CO2 is a critical part of the Carbon Cycle – which used to be taught to every kid in high school – on which all life on Earth depends. No atmospheric CO2 => no plants => no animals (including humans).
But CO2 also makes more immediate contributions. The UK is reportedly facing a problem because natural gas (a fossil fuel) has become too expensive, and fertilizer factories have shut down (meaning problem for food supplies in the UK next summer). A by-product of the fertilizer factories is … CO2. That by-product gas was needed both to calm chickens & pigs in slaughterhouses and to preserve meat. Near-term impact on the price & availability of meat.
The Global Warm-Mongers are blindly playing with complex inter-related systems that they do not understand.
Every living animal exhales CO2 all day, every day. Want to get rid of that awful CO2? Kill all the people and animals. The whole thing is a lot of BS, and a total waste of human brain power. It’s just another way to impose Marxism on the world.
Use any number you want but at 4 generations per century, 1250 years. At the current rate of around 3 ppm/year, the level would reach around 4000 ppm. That would be around .4% if I got the math right.
I have no personal problem with nuclear fission, but it’s a hard political sell and it’s hard to get the cost of power down to where you can make low cost liquid fuels on which our civilization depends.
I wonder if anyone besides me has ever looked into the cost to produce fuels from electric power? It’s not hard to do starting with Sasol’s GTL plant in Qatar.
Set that 1,250 years for CO2 Armageddon against the Reserves/Production Ratios commonly used in the fossil fuel industries – established extractable volumes in the ground divided by the current production rate, generally expressed in years. Lots of room for arguments about what to include in “reserves”, but the scale of the estimates is typically around 100 years for coal, and about 50 years for oil and gas.
The Warm-Mongers seem to assume that there are infinite amounts of fossil fuels to generate infinite amounts of CO2 – when quite clearly there are not. We cannot avoid the conclusion that geologist Marion King Hubbert reached in his 1956 (1956 !) paper “Nuclear Energy and the Fossil Fuels” – on a 10,000 year civilizational time line, human use of fossil fuels will be seen as a blip.
The challenge is to find an alternative practical 24/7 affordable non-subsidized very large scale source of power before physical limits cause the extraction of fossil fuels begins slowing down.
Subsidy Hogs such as environmentally-damaging bird-whackers and imported Chinese solar panels won’t do it. Hydro-power is viable, but limited in scale. Geothermal is also limited in scale – and in most places is effectively non-renewable. Tidal power again is very limited in scale, and mostly a joke. Everything else, from nuclear fusion to power satellites, is at present not technically feasible, and may never be economically feasible.
Hubbert’s point back in 1956 (1956 !) was that — fortunately! – the human race has already identified the next large scale energy source, nuclear fission. You are quite right that the Usual Suspects have made this a “hard political sell” in the West for the last half century. But look at what Russia and especially China are doing now. They will survive. Will the West ?
I’m still working on sinking carbon-sink trees in the deep ocean. Cellulose, compacted with the air and water compressed out, has a density of 1.5 g/cm³ and should sink easily. The other component of wood is lignin, which is a much more complex molecule whose structure is not known precisely, as a family of similar compounds is found in wood. References give the density of lignin between 1.35 and 1.5 g/cm³, again substantially denser than water. The fraction of cellulose and lignin in wood depends upon the species of tree, but most wood is predominately cellulose with lignin as a binder. Lignin is what causes paper made from wood pulp to yellow, in case you needed to know that.
You’d think I’d be clued in on the properties of lignin, since I’ve lived for thirty years in the Commune de Lignières NE, Switzerland, whose name was derived from its abundant timber being a source of wood (lignum) during the Roman occupation some time before I arrived. But the fact is, lignin is such a complex molecule and varies so much in the details that it’s difficult to find numbers to characterise it in the Junior Woodchucks’ Guidebook.
But still, it appears that after you squeeze out the air and water by sinking unwanted trees in the deep ocean, what remains is denser than water and they’ll sink, not float. News you can use!
It sounds feasiable – but (always a but), it will take energy to do that squeeze. Probably something bigger than a car-crusher! And that energy will have to come from somewhere. Maybe from burning some of the trees.
Gravity will do the work, in the guise of pressure in the ocean. You’ll need an energy input to force the initial volume down to a depth where water pressure compacts the payload to a density greater than that of water. From that point on, it will fall under the force of gravity and provide a force which can be used to lower additional payload to the point where it contributes to the down force. Whether this is net positive of energy is in the details, but it won’t take anywhere near as much energy as sinking the uncompacted mass to the ocean bottom by pure force.