Or, we should just get used to live with more CO2 in the air.
Or, have less people producing waste everywhere.
We need to take CO2 out of the sky – an overview of climate tech
81–90 of 267 posts
Re: We need to take CO2 out of the sky – an overview of climate tech
#82Just pump air into ponds of algae/kelp or grow Azolla on the surface. Feed it with fertilizer runoff that's otherwise thrown into the rivers, seas, oceans. No need to build expensive solutions to remove CO2 from the atmosphere.
that sounds like an expensive solution. I can't napkin math any of this since I don't know how much CO2 you could extract along with the other engineering and logistical problems:
* which areas are suitable
* how much energy is required
* how much area of land is required.
I hesitate to give credibility to any answer that starts with 'just... [do this thing]'.
If you have any references I'd be curious to learn more
Re: We need to take CO2 out of the sky – an overview of climate tech
#83I'm interested to see what comes of this: https://projectvesta.org/
Hi thanks for the mention! We are available to answer any questions. And we'll have a new version of the website out soon with some updates.
Thanks. I actually just took a look around there and was disappointed there wasn't a 'News' section or something like that, so glad to hear there will be updates soon!
I do have one other question: is there any chance you'll partner with a Canadian charity, or other ex-US charities for that matter, to accept tax-free donations from other countries?
Re: We need to take CO2 out of the sky – an overview of climate tech
#84Earlier quoted context omitted.
I had the same thought as well. It's an option, but the energy required to cool air to the precipitation point of CO2 (-79C) is pretty large, and the cooling process itself will produce greenhouse gas, so you end up with a pretty small return.
How do you calculate how much energy is required? You would use cooled separated products to pre-cool incoming stream of "dirty" air. CO2, having low concentration, won't fall off at -79C (or we'd have that effect in Antarctica today), but if you go to ~-140C, you'll have some results. Why cooling process will produce greenhouse gas? You'd use energy from "green" sources to compensate for required expenses.
-140C only works for CO2-rich streams (> 10%). As the partial pressure of CO2 decreases, you'll need to get asymptotically closer to the melting point of oxygen/nitrogen. You'll also need to increase the pressure, but again that only gets you reasonable temperature gains if the partial pressure of CO2 is >>0mmHg. Currently it is 0.3mmHg @ 400ppm. In short, this is not a viable method for removing CO2 from the atmosphere.
For a fun take on some of this see https://wattsupwiththat.com/2009/06/13/results-lab-experimen...
Re: We need to take CO2 out of the sky – an overview of climate tech
#85What the article leaves to the conclusion is what needs to be stated up front and center: it's virtually impossible to do this efficiently, cheaply, or effectively because there's so little CO2 in the air, meaning a) adding even a little bit more greatly affects the CO2 levels b) with a global ppm of ~400, it basically means that you need to filter 2500 molecules of air to get a single molecule of CO2, and that's ass…
If you can capture the CO2 using transient power from wind or solar and use it to make a synthetic fuel, then you have a potentially viable option. Carbon Engineering in Squamish BC is doing this for $100 a tonne. Their synthetic fuel costs about $2/L to make - still too expensive, but not if the carbon price rises to about $100/T.
That’s way better than I thought it would be, aren’t some European countries fairly close to that mark?
Re: We need to take CO2 out of the sky – an overview of climate tech
#86Earlier quoted context omitted.
I had the same thought as well. It's an option, but the energy required to cool air to the precipitation point of CO2 (-79C) is pretty large, and the cooling process itself will produce greenhouse gas, so you end up with a pretty small return.
Antartica is -56C right now. Another 23C should be manageable. This doesn’t have to be done in the tropics.
https://wattsupwiththat.com/2009/06/13/results-lab-experimen...
I made some slightly more detailed posts elsewhere but this article addresses your point directly. Essentially, this is not a viable method for removing CO2 from the sky, because there's so little CO2 in the sky that it changes all the basic physics assumptions.
This is actually relatively basic undergraduate level napkin math from a chemical engineering perspective, but outside of that discipline most people understandably don't have experience with estimating physical states of mixed gases.
Re: We need to take CO2 out of the sky – an overview of climate tech
#87I'm interested to see what comes of this: https://projectvesta.org/
Hi thanks for the mention! We are available to answer any questions. And we'll have a new version of the website out soon with some updates.
I have a lot of questions about the feasibility of projectVesta. What's the best communication channel?
Re: We need to take CO2 out of the sky – an overview of climate tech
#88Earlier quoted context omitted.
It only has to do it cheaply now because there is NO COST to putting CO2 into the air. Why are people surprised that if something is free (pumping CO2 into air) demand for it is high? You are telling me that doing a charge of let's say $10 - $100/ton of CO2 wouldn't have a DRAMATIC impact on emissions? Is $10 - $100/ton too little for a supposed climate emergency? There is so much funding and lawmaking and finger poi…
You mean a Carbon Tax ? The tax that applies to every single business, every single product, every single process, everything. The one that causes every single vested interest to come out of the woodwork and join together to make it politically toxic. We tried this in Australia. It has killed every government that even dared to discuss it. And politically it is utterly impossible to defend e.g. "Carbon tax that raise…
Why not have the level of sales tax (VAT in the UK) vary depending on amount of C02 was used to create a product. The consumer would not pay any more on average.
Re: We need to take CO2 out of the sky – an overview of climate tech
#89We don't need to remove CO2 from atmosphere.
Let warming happen.
Everything will be okay.
Re: We need to take CO2 out of the sky – an overview of climate tech
#90What the article leaves to the conclusion is what needs to be stated up front and center: it's virtually impossible to do this efficiently, cheaply, or effectively because there's so little CO2 in the air, meaning a) adding even a little bit more greatly affects the CO2 levels b) with a global ppm of ~400, it basically means that you need to filter 2500 molecules of air to get a single molecule of CO2, and that's ass…
As you write, plants can do this quite efficiently via photosynthesis. So there is at least one working example where CO2 capture is resource-efficient (even solar-powered). From photosynthesis we get sugar. From sugar we can get to raw (solid) carbon for long-term storage. Forests are not the only option. Imagine large installations with tanks of algae under a white canopy. I imagine the economies of scale are huge…
The mechanisms for us (people everywhere) to begin paying for it is crucial, as there are a number of technologies on the cusp of being useful for tackling this problem, however they are not cheap. Cheap solutions to CO2 are rare and tend to only apply to point sources at best.
Large scale solutions that help mitigate the existing CO2 are going to require some significant capital and operational expenditure.
The cheapest large scale solution actually requires less money, and more legal / willpower. But I’d argue it’s also harder to measure concrete impact and “monetise” oceanic surface iron enrichment. It’s harder to convince people to pay for estimated results even ones based on measurement and science, than results containing physical outputs, like actual solid/liquid/gaseous CO2.