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Carbon Removal Technologies

carbon.ycombinator.com

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Re: Carbon Removal Technologies

#91

Post by Retric »

Symmetry wrote: post #53
Retric wrote: post #26

Earlier quoted context omitted.

Because the earth is effectively a black body it cools down at T in kelvin^4. This means you need to block a huge amount of energy ~2% of the sun to get around global warming. Sticking something at L1 looks elegant, but you cant just toss junk there it needs serious station keeping making it far more expensive than many assume. PS: Unfortunately, as a side effect you reduce the energy of all plant life by ~2% solar p…

The launch volume looks infeasibly large in the foreseeable future, but I don't think the station keeping problem is that bad. Any sun shade is basically going to be a solar sail already and steering via LCD panels like IKAROS did should be sufficient. https://en.wikipedia.org/wiki/IKAROS

The problem is you now need some actual structure rather than just some thin sheets / inflatable structure or whatever. Further applying even small amounts of force across huge sheets adds up while as you say it's acting like a solar sail.

That is to say it's clearly still possible, just not as cheap as people are assuming.

Re: Carbon Removal Technologies

#92

Post by sradu »

clomond wrote: post #89

I appreciate the focus here and applaud all progress and work related to any kind of carbon capture/sequestration technologies. These approaches are necessary and important. BUT I think it is too often overlooked that a fundamental prerequisite for making any meaningful progress in this area predicates on cheap, affordable, abundant "clean" energy. Anytime you talk about hydrolysis, desalination, or increasing concen…

Each proposed idea has a section related to energy requirements.

Re: Carbon Removal Technologies

#93

Post by marmadukester39 »

btilly wrote: post #59

I would strongly suggest investigating the claims of http://www.innovationconcepts.eu/res/literatuurSchuiling/oli... that after mining, milling, and then being spread in the ocean, olivine rocks weather quickly and take out CO2. The estimated costs of large scale CO2 sequestration this way are surprisingly reasonable, and the technology is already available. Also the various ocean technologies are going to run into t…

What about doing it in landlocked major bodies of water? I'd sacrifice the Great Lakes for the climate.

Re: Carbon Removal Technologies

#94

Post by lchengify »

WhompingWindows wrote: post #5

Can we discuss space sunshades? Assuming the cost of getting freight to orbit goes down substantially as companies like SpaceX ramp up launches, what's the limiting parameter on some sort of sunshade over the north and/or south pole? Is it indeed the cost of launching the sunshade, or are there other factors at play which make the space sunshade unrealistic? What materials would be reflective and resilient and cost-e…

I think Nathan Myhrvold [1] proposed something like this. There's a summary of it on one of the Freakonomics podcasts, but the summary is basically that it acts like an erupting volcano to cool the earth slightly.

"MYHRVOLD: So, climate change is a 1-percent effect. Now all we have to do is make the sun 1 percent dimmer. Now I don’t literally mean changing the sun. But there are a variety of things that bounce sunlight back into space. Clouds are one of those things: white clouds bounce white light back up into space. It turns out that volcanoes throw ash and particles, if it’s a big volcano, very high in the atmosphere. That reflects some of that light. And in fact this happened in 1991 when Mount Pinatubo went off. It cooled worldwide temperatures by a degree, degree-and-a-half-Fahrenheit for 12 to 18 months. Well, my company has come up with some very practical and cost-effective ways of deliberately putting particles into the upper atmosphere. And on paper, it works out that you could nullify all of global warming that way." [2]

[1] http://www.nathanmyhrvold.com/ [2] http://freakonomics.com/podcast/save-the-planet/

Re: Carbon Removal Technologies

#95

Post by soperj »

lowdest wrote: post #29
GreeniFi wrote: post #2

We already have carbon removal technology. They’re called trees. [Edit] I’m not being facetious. 40% of emissions are as a result of poor land management. We’ll need all the technological help we can get, but if we can’t manage land as carbon stores - not sources, we’re not going to win this race.

Trees ultimately burn or rot, releasing a large portion of that carbon back into the atmosphere. Cutting them down and burying them to grow more would be ideal, but takes additional work. Someone want to engineer a tree with enormous, deep roots? Basically make the trees self-burying.

We're essentially doing just that when we use the wood for housing and other products and then eventually landfill, then you can plant more trees on that land.

Re: Carbon Removal Technologies

#96

Post by ChuckMcM »

bobthepanda wrote: post #82
btilly wrote: post #59

I would strongly suggest investigating the claims of http://www.innovationconcepts.eu/res/literatuurSchuiling/oli... that after mining, milling, and then being spread in the ocean, olivine rocks weather quickly and take out CO2. The estimated costs of large scale CO2 sequestration this way are surprisingly reasonable, and the technology is already available. Also the various ocean technologies are going to run into t…

I mean, do we know that local toxic algae blooms are the only effect this will have? This to me smells like it could have potential unforeseen consequences like the Deepwater Horizon cleanup.

The point is perhaps that we know we're driving off a cliff. Is this going to slow us down or not? If you look at the proposals, what does setting up half the land mass of the Sahara as algae lagoons do? How does that affect local weather patterns, wildlife, Etc.

The argument that the action may be dangerous is not as compelling when the prognosis for inaction is bleak.

Re: Carbon Removal Technologies

#97

Post by Retric »

Tuna-Fish wrote: post #64
Retric wrote: post #26

Earlier quoted context omitted.

Because the earth is effectively a black body it cools down at T in kelvin^4. This means you need to block a huge amount of energy ~2% of the sun to get around global warming. Sticking something at L1 looks elegant, but you cant just toss junk there it needs serious station keeping making it far more expensive than many assume. PS: Unfortunately, as a side effect you reduce the energy of all plant life by ~2% solar p…

Earth-Sol L1 is probably a bad place for a solar shade. That's where a solar shade of any given size is the most efficient, but the cost of getting it there is much more than the cost of having more, less efficient ones. A better choice is something akin to a semi-sun-synchronous Molniya-style-orbit. That is, orbit that is somewhat highly elliptical (so a satellite on it spends most of it's time near apogee, and zips…

LEO to L1 is not that bad using solar sails or ionic propulsion.

There are going to be real trade-offs to any orbit, but I think the minimum cost is going to be above X mass in L1 means X mass into LEO as you can't use less mass than that in any other orbit.

Re: Carbon Removal Technologies

#98

Post by hinkley »

lowdest wrote: post #29
GreeniFi wrote: post #2

We already have carbon removal technology. They’re called trees. [Edit] I’m not being facetious. 40% of emissions are as a result of poor land management. We’ll need all the technological help we can get, but if we can’t manage land as carbon stores - not sources, we’re not going to win this race.

Trees ultimately burn or rot, releasing a large portion of that carbon back into the atmosphere. Cutting them down and burying them to grow more would be ideal, but takes additional work. Someone want to engineer a tree with enormous, deep roots? Basically make the trees self-burying.

Too narrow a view.

The tree already buries almost half of its biomass in the ground for you. And a lot of material goes through the food chain when the tree rots in situ. There's a big difference between regrown forest and converting prairie to forest and a lot of that has to do with quantity and quality of decaying matter on the forest floor. Dead trees are better than no trees.

Re: Carbon Removal Technologies

#99

Post by philwelch »

I wonder why we can’t just extract CO2 and H2O from the atmosphere and recombine them back into hydrocarbons. Not only would this give us a closed-loop supply of hydrocarbons (meaning you could have things like airplanes) but you could just sequester the carbon by storing the hydrocarbons. The only problem is that it takes a lot of energy (more energy than we got from burning those hydrocarbons in the first place) but it would be great to solve the energy storage and carbon sequestration problems at once.

Re: Carbon Removal Technologies

#100

Post by toast0 »

cure wrote: post #28
tareqak wrote: post #6

Earlier quoted context omitted.

I guess trees could be planted more creatively. There is one particular situation where I think they should cut down / or move trees, and that is when trees are near power lines: it's basically a matter of time of when the tree falls down and the local power company has to fix the power line and the local population has to deal with the disruption in power. Maybe there is a good business in finding a good way to trul…

Or you could just have the power lines under the ground . If they are low enough to be endangered by falling trees, they could perhaps go underground instead. No need to cut down trees or maintain buffer zones along power lines. No annual periods of days/weeks without power for affected areas.

Underground power can solve tree fall issues. But it is much more expensive, both initially, and when any repairs or new connections are needed. The number of repairs likely goes down, but time to repair goes way up. In some areas, soil conditions make it pretty much impossible.

Trenching for the install may require more plant disturbance than would be needed to maintain nearby trees on a regular basis.

Distributed generation and redudnant distribution can help reduce the impact as well. Everything costs money though.

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