Sequestering Carbon Dioxide

[Geof]

Sequestering carbon dioxide has been proposed as a method for combatting Global Warming. That is removing Carbon Dioxide from the atmosphere or never allowing it to escape into the atmosphere. This is done by sealing the Carbon Dioxide away somewhere; Deep Ocean Trenches, underneath Salt Domes in oilfields or chemically combining the Carbon so it is not available to form Carbon Dioxide.

This Poll has four choices, explain the reasoning behind your choice.

P.S. It is a trick question.

[fyffe555]

I said none for the simple fact that we produce it by merely breathing.. net net we haven't reduced co2 by sequestering anything. Do I win a prize?

made me think though, if we're to reduce co2 what about co2's other uses. For example some people I know produce/use more co2 through thier soda habit than thier car produces. Are we going to stop using co2 as a shield gas in mig welding? What about the paintball guys - will they have to pay a 'carbon offset'?.

Today at the Borg there was a display for a Prius claiming how much gas it saves and how little co2 it produces. Immediately next to it Kobalt introduced a new product for air tools - Co2 tanks for 'mobile power'.....

Lunatics have taken over the assylum.

[awright]

I'm confused by the poll wording. Are you really asking how much CO2 has been SEQUESTERED, i.e., taken OUT of circulation in the biosphere and atmosphere, or how much has been RELEASED from its natural sequestration in bogs, marshes, tundra, oceans, petroleum coal, etc.? I wouldn't be surprised if the responses so far confuse the question also, thereby making the results meaningless.

fyffe555's comments reflect the general confusion in the populace. Use of CO2 in soft drinks, shielding gas, paintball guns, fire extinguishers or any other industrial application are complete non-issues in the question of CO2 as a greenhouse gas. These used do not change in any way the net amount of CO2 causing global warming because they distill CO2 out of the atmosphere, use it, and release it back into the atmosphere.

What DOES release carbon from its natural sequestration is extracting petroleum and coal that has sequestered carbon in deposits in the earth's crust for much longer than humans have existed and burning it, releasing the carbon therein in the form of CO2.

In general, burning of renewable fuels like biofuels (wood and agricultural wastes and plant-derived oils) does not contribute to CO2 as a greenhouse gas because the CO2 released is recycled out of the atmosphere into now biomass.

Your poll question is quite appropos, but I think it needs rephrasing to be of value.

awright

[Geof]

Originally Posted by awright I'm confused by the poll wording. Are you really asking how much CO2 has been SEQUESTERED, i.e., taken OUT of circulation in the biosphere and atmosphere,.....awright

Sequestering carbon dioxide...That is removing Carbon Dioxide from the atmosphere or never allowing it to escape into the atmosphere.

Your phrasing above, mine below, I fail to understand your confusion.

How much CO2 has human activity removed from the atmosphere?

[awright]

OK, I understand the language. What I do not understand is the thrust or purpose of the question.

I'm no atmospheric scientist. However, my understanding is that the only large scale human activity that sequesters CO2 is capturing combustion gasses or other products of industrial activity in a scrubber and somehow storing it or chemically combining it in a form that can be injected underground in deep cavities that hopefully will not allow it to escape back into the atmosphere. I'm sure there are many other processes in use and there are certainly many that are proposed, but all of them combined are a drop in the bucket compared to both the magnitude of the NEED to sequester CO2 and the new releases of CO2 by burning of fossil fuels.

Asking how much CO2 human activity has removed from the atmosphere instead of asking how much CO2 human activity has put into the atmosphere simply seems pretty silly to me and doesn't seem to contribute much to the dialogue on greenhouse gasses and the need or not in doing something about it.

I do see the statement, "P.S. It is a trick question." I hope we see what the trick was sooner or later.

Don't fyffe555's comments reveal confusion about the question that is being asked or the science behind the question? Breathing contributing to greenhouse gasses?

fyffe555 makes a chiding comparison of the claim by Prius to reduce CO2 emissions with the use of bottled CO2 to power air tools. In fact, while driving a Prius is not a solution to the CO2 greenhouse gas problem, it does, in fact, reduce CO2 release into the atmosphere from sequestration in petroleum underground per mile driven in ordinary cars, while using CO2 to power air tools has no net effect on greenhouse gas.

I'm not really trying to shoot down anyones trick question here. I was just trying to make the point that I think many people will be confused by the question and that the results won't mean much. But I'm probably missing the point.

awright

[Geof]

awright;

You accuse me of being confusing: Fair enough, I get accused of being confusing even when I am doing my damndest to be clear so I guess when I am deliberately not being clear getting that accusation is understandable.

The purpose of the question/poll? Partly for fun, partly to see if people read things and put two and two together. You did and what you posted is very informative.

You have the question; "Breathing contributing to greenhouses gases?". The question mark leads me to conclude that you think this is a silly concept. It is, but based on the comments I have seen and heard some people make it is a popular misconception that CO2 exhaled by living creatures is contributing the atmospheric CO2 levels.

Another of your comments is; "I'm sure there are many processes...that...combined are a drop in the bucket...". I agree but again it seems to me that many people have the idea that carbon offsets for forest preservation or planting are a practical approach and that forests sequester carbon.

I think this is mostly nonsense; it is an extension of the conception of forests, most specifically the Amazon Rain Forest as 'The Lungs of the Planet'. Ignore for the moment that this simile is wrong because lungs expel CO2...the common meaning is that the trees of the rain forest provide the oxygen we need, or that life in general needs. Balderdash! The oxygen we need is released by the plants that are grown for our food. Individual trees may sequester carbon, forests, mature old growth forest that is, do not because in a forest decay matches growth.

The trick question comment, which with hindsight maybe I should have omitted, is that to some extent all choices are correct as I explain below.

The item that was the distal cause of the poll was the Ozzie Biologist that I referred to in my thread on Cremation. His claim that incinerating human corpses released 50kg of CO2 into the atmosphere (this is just the CO2 from the corpse not from the fuel used in the incinerator) is correct; give or take a bit for different sized people. But what he skips over and what most people skip over, is the realization that this is not a net contribution to global CO2; it is simply returning to the atmosphere the CO2 that was sequestered in the living human during their life. This is where the 150 billion comes from; 50kg multiplied by 6 billion divide by two because not everyone is full grown.

So therefore a correct answer on the poll is the fourth choice; humans by their own individual personal activity have sequestered 150 billion kg of CO2 from the atmosphere, in themselves. The first answer is probably also correct; I don't think anything of significance has been sequestered by deliberate industrial activity. Possibly some has been used for oil well rejuvenation but the purpose behind this is not sequestration it is oil extraction so it hardly qualifies. Naturally if both the first and last choices are correct in their own way the other two are also correct.

[awright]

Ah-Ha! Now I get the trick. Of course, any increasing sequestration of carbon in human bodies requires continually increasing human biomass which we are seeing has its own, much more severe impacts on the planet.

I hope you are not suggestion that we can destroy the rainforests with negligible impact on human welfare on the planet.

By the way, how do you arrive at the conclusion that growing food replenishes oxygen more than the rainforests? Has somebody analyzed the relative magnitudes of the CO2/O2 cycle in agriculture vs. nature?

Thanks for the interesting descussion. My comments were not intended as an attack.

awright

[Geof]

Originally Posted by awright Ah-Ha! Now I get the trick. Of course, any increasing sequestration of carbon in human bodies requires continually increasing human biomass which we are seeing has its own, much more severe impacts on the planet. I hope you are not suggestion that we can destroy the rainforests with negligible impact on human welfare on the planet. By the way, how do you arrive at the conclusion that growing food replenishes oxygen more than the rainforests? Has somebody analyzed the relative magnitudes of the CO2/O2 cycle in agriculture vs. nature? Thanks for the interesting descussion. My comments were not intended as an attack. awright

Yes sequestering Carbon in human bodies may not be the answer. Although in a different thread I did point out that it is our patriotic duty to die as large as possible and be interred in a hermetically sealed crypt so we never decay. Someone else pointed out that the first part of the duty is being fulfilled by an increasing proportion of the population.

NO I do not suggest destroying rainforests; that releases the Carbon that is in the standing biomass. However, replacing destroyed forests does nothing to compensate for fossil fuel use; all this does is replace the standing biomass of the lost forest.

Regarding the O2 replenishment CO2 removal. It is a fact of chemistry that the oxygen we need to metabolize our food was freed during the growth of that food. The relative size of agriculture versus nature does not come into it. Note that I did not say agriculture, the growth of our food, makes more oxygen than the rainforest I said it makes the oxygen we need, we don't need any from the rainforest.

I did conflate the food and forest in sequential sentences but they can be viewed separately. All life participates in the carbon cycle; and it is a cycle combined with oxygen. Water comes into it but does not alter the analysis that can just consider carbon.

All the carbon in carbohydrates, etc, comes from CO2 via plants and in the process O2 is released into the atmosphere. In the process of photosynthesis solar energy is stored as chemical potential energy mostly in the carbon hydrogen bonds in carbohydrates. When we metabolize food we are simply releasing this chemical potential energy and using it to drive other chemical reactions that keep us operating. Chemical stoichiometry tells you that the same ratio of atoms have to be involved in the reactions whether they are storing energy or releasing energy. Granted we do not metabolize all our food, some passes on to serve the requirements of the bacteria, etc at the local sewage treatment plant. In addition some of the carbon in the food goes into making us grow and has to await our death before it reneters the cycle; this is the sequestered carbon. And all of this takes place spread out over time and space.

The rain forest cycle is fundamentally identical; plants grow and die, get eaten by insects and bacteria. It is more tightly coupled than agriculture because the food doesn't get transported around the world or stored for months. And The Tropical Rainforest is a prime example of very tight coupling. In this ecosystem the nutrients freed by decay do not even get a chance to be deposited in the soil. Practically everything is tied up in growing or decaying biomass. Fungi and moulds that live in association with tree roots deliver nutrient directly from the plant material they are decomposing to the roots of the growing trees. The soil of a rainforest is impoverished, it has a very low nutrient content and a very low humic acid content; everything is reutilized before it gets to the soil. This is well demonstrated when the forest is felled and the land used for agriculture; maybe one or two crops can be taken off before the productivity plummets.

This is why I can make my Balderdash claim. The carbon/oxygen cycling in a rainforest is very tight; there is no appreciable sequestering of carbon therefore no free oxygen production. This also is why I say forests do not sequester carbon while individual trees may.

I realise that some scientists have claimed forests do sequester carbon and I am quite willing to say balderdash to their face until they can show me how this happens if the floor and soil of these forests has not accummulated large quantities of organic material over the past few thousand years. It simply is not there.

Peat bogs are a different thing entirely; they do sequester carbon because decomposition is inhibited by the stagnant standing water. Peat bogs eventually assume a dome shape rising above the surrounding terrain. The height of the dome is constrained by the rainfall more than by the growing season; if the top of the dome drains too dry for too long during the warm season decomposition balances growth and the bog dome does not grow any further. So in fact it is safe to say that a mature peat bog does not sequester further carbon. And the way to start releasing the carbon from a peat bog is to lower the water table; this has been done in many places and once done is practically irreversible.

I didn't interpret your comments as an attack more as a demand for elucidation. I am attacking though...but not you or anyone else who may question what I write. I am attacking the mythology and balderdash that is promulgated by so many influential people.

[dertsap]

Originally Posted by Geof I realise that some scientists have claimed forests do sequester carbon and I am quite willing to say balderdash to their face until they can show me how this happens if the floor and soil of these forests has not accummulated large quantities of organic material over the past few thousand years. It simply is not there. .

if the floor hasn t accumulated organic matter over time , then something must be affecting the plant life to not allow it to grow ,which would lead me to beleave that the forest (trees) may sequester co2 , plants need oxygen at the root in order to grow , if there are too high of a level of co2 in the soil then plant life will not grow

[iamscottym]

How about we sequester carbon in the form of carbon fiber. I volunteer to store as much as my house can hold, for free!