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We need to take CO2 out of the sky – an overview of climate tech

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Re: We need to take CO2 out of the sky – an overview of climate tech

#101

Post by hnarn »

the6threplicant wrote: post #91

One of the problems I see with CO2 sequestration is that it will be a nice way for companies to suck at the teat of taxpayers the world over. I'm sure Halliburton-like companies have a 3 step plan to be right at the front of the money firehose when governments are forced to reduce CO2 or face even bigger costs (both financially and politically) in the coming decades.

This assumes that the only way a project like this could be pulled off would be for the state to open a "money firehose" and spray it onto buckets held by private corporations. Is there any reason it couldn't, in theory, be a state controlled venture? Especially for something as seemingly basic as "planting trees", I don't see where the corporate expertise comes in that the state could never replicate.

"The state will handle this" is not only a legitimate structure in totalitarian dictatorships, it's used across the developed western world for most public services.

Re: We need to take CO2 out of the sky – an overview of climate tech

#103

Post by [deleted] »

Phenix88be wrote: post #100

Article like this make me so depressed. The conclusion is always (from my point of vue) : we are fucked. We need a magic device that will remove gigatons of CO2 out of the atmosphere in less than 30 years and we need it to do it without using energy or consuming rare material. And you can't do much with CO2 at the end.

[deleted]

Re: We need to take CO2 out of the sky – an overview of climate tech

#105

Post by dcolkitt »

AncientTree wrote: post #60

My biggest concern about CO2 is the cognitive impact it has on humans - at levels 800ppm and higher, mental performance is impacted. It will take a while for the atmosphere to reach this level (hopefully it never does), but it is common inside houses and offices. As atmospheric CO2 rises, it becomes more difficult to ventilate buildings, and human mental performance degrades. In terms of geoengineering, it seems like…

The amazing thing about stratospheric aerosol injection is that fully negating the effect of global warming would cost less than $5 billion per year.[1] That's less than 0.01% of world GDP. That's cheap enough for a single major country to unilaterally take on itself.

In contrast going fully carbon neutral would cost the economy at least 100 times that amount. And even then it would still result in some amount of warming between 1.5-3 C. Plus require multilateral commitment from nearly every country.

To me the calculus seems to strongly favor forgetting about carbon mitigation completely. Instead just focusing on immediately starting aerosol injections. The tech already exists and is ready to be deployed. Starting sooner will give us time to get better at using it, and discover any potential pitfalls.

Then in 100 or 200 years, we can switch over to more advanced geoengineering that fully and permanently scrubs carbon out of the atmosphere. Aerosol injection would act as a stopgap measure until the carbon-scrubbing is cost-effective.

[1] https://iopscience.iop.org/article/10.1088/1748-9326/aae98d

Re: We need to take CO2 out of the sky – an overview of climate tech

#107

Post by baq »

threeseed wrote: post #45
privateSFacct wrote: post #37

Earlier 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…

don't call it tax, call it carbon dividend and give the collected money away to citizens.

Re: We need to take CO2 out of the sky – an overview of climate tech

#108

Post by kuu »

baq wrote: post #106

recommended related reading: https://en.wikipedia.org/wiki/Azolla_event "The event coincides precisely with a catastrophic decline in carbon dioxide levels, which fell from 3500 ppm in the early Eocene to 650 ppm during this event."

This event lasted for "800,000 years", based in the article.

Re: We need to take CO2 out of the sky – an overview of climate tech

#109

Post by adrianN »

jpfr wrote: post #79
ComputerGuru wrote: post #28

What 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…

Photosynthesis manages to convert about 1% of the sunlight into chemical energy. I wouldn't call that efficient. The big benefit of plants is of course that they're relatively low maintenance. You still need to cut them down and turn them into charcoal if you want to capture that carbon for good.

Now look at the gigatons of coal we already dug out of the soil and burnt. That's a lot of forests you need to plant, cut down, and turn into charcoal. It might be doable, but it certainly won't be cheap or easy.

Re: We need to take CO2 out of the sky – an overview of climate tech

#110

Post by adrianN »

peteretep wrote: post #73
avmich wrote: post #64

Earlier quoted context omitted.

You don't want to do unnecessary transformations, to preserve as much energy as possible (so the turbine, which is needed for cooling, should work on small pressure difference). So, no air liquification - just let CO2 separate and send cleaned air back to the heat exchanger.

> to preserve as much energy as possible Aren't there plenty of places where energy is so plentiful that you don't need to care that much?

Not really?
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