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Comment by protomyth | Hacker News Reader

Can the CO2 be removed from the ocean and broken into C and O2? Is this geo-engineering we can do?

We are actually a week from the anniversary of the world's first act of geo-vigilantism: http://www.newyorker.com/online/blogs/newsdesk/2012/10/the-f....

Really fascinating stuff.

> ... nearly all agree that we need to move with great deliberation when altering the ecosystem of the ocean.

It's been quite a while since Humanity applied anything like deliberation to our ongoing alterations of ocean ecosystems.

The biggest risk is doing nothing at all.

There is a proposed geoengineering approach, but the authors of this page don't recommend it:

https://web.duke.edu/nicholas/bio217/spring2010/chang/GeoEng...

http://www.cquestrate.com/the-idea

Are the authors against all geo-engineering or just this plan?

They seem very in favor reducing over-fishing, switching to clean energy sources, etc. They're only in favor of geoengineering if politicians can't get their shit together and we end up on the brink of a disaster.

"We do not promote the use of the [geoengineering] method highlighted in this section. We merely present it here as an interesting solution proposed by the field of geoengineering, a popularly growing discipline which seeks to provide technical solutions which manipulate the earth’s climate in order to counteract the effects of global climate change."

"Any solution proposed by the field of geoengineering is akin to addressing the symptoms and not the source of the problem."

-- https://web.duke.edu/nicholas/bio217/spring2010/chang/Soluti...

The symptoms are all we care about, why would anyone give a shit about CO2 levels if it didn't cause global warming?

It's not like it's toxic. If it's cheaper to geoengineer the CO2 away, why not?

Fossil fuels are not a long-term energy solution in any case, so it makes more sense to attack the problem from that angle.

And I suspect the answer is that it's not cheaper. I'm unaware of any cheap, scalable, safe method of reducing CO2 levels. It's difficult to conceive of a practical solution to global warming that doesn't involve drastically reducing the ongoing CO2 output. How are you going to balance out 30+ billion tonnes of carbon dioxide per year?

Not without a significant energy expenditure.

But most of our energy sources of course produce CO2 and other products.

I guess the Scifi question is can you build a nuclear ship with some apparatus that pulls the CO2 out of the ocean and breaks it into C (stored on ship) and O (released into atmosphere)?

I don't see why you couldn't.

Most large navies run nuclear reactors on board their ships. IIRC, nuclear submarines pull water and use a portion of reactor power to get fresh oxygen.

But I'm also not sure that the reaction is as easy as it sounds. First of all, manufacturing such a ship would likely cause a great deal of greenhouse emissions. Would the ship's benefit offset the pollution it implicitly creates as it is built? How about the pollution generated by its operation? No engine emissions, but when the reactor gets decommissioned it'll have to be buried, likely by diesel-powered equipment and covered in concrete which is manufactured in a dirty process. Tugboats aren't nuclear powered. Re-fuelling apparatuses aren't nuclear-powered. Crew will produce waste, reactor needs to be cooled which introduces unwanted heat to the water, etc etc etc.

Would it even be economically possible to build/operate?

How many ships would be required to make a measurable impact?

You could build one ship, but you'd need to build and power millions of them to have any impact.

You'd have to reduce the CO2 resulting from the combustion of coal and oil during the whole industrial era, or maybe a bit less, but it gives you an idea of the magnitude of the task at hand.

It'd be far more efficient to replace coal power with nuclear power plants.

What's wrong with solar powered floaties to do that job? We could make them in the shape of yellow rubber duckies!

When asking about our ability to geiengineer, remember that we are the once that caused this problem in the first place, and without even trying. Having said that, releasing CO2 is a much easier problem than removing it. As to your proposal, CO2 would decompose into C2 and O2 (with twice as many O2 molecules). Incidentally, C2 is a strong acid [1]. Additionally, breaking CO2 this way would move it to a higher energy state, and therefore require a net input of energy. (Technically, given what I know, it is possible that there is just a high activation energy to do this, but seeing as CO2 is such a common product of energy releasing reactions, including metabolism, I'm pretty sure it is just a low energy molecule). Also, it took pretty much all of our industrial force to introduce the CO2 in the first place, and there was huge economic incentive.

The more popular ideas in geo-engineering are to let nature do the hard work for us. For example, a common idea is to introduce iron to the ocean. This would increase plankton populations, and the plankton would then use solar power to remove CO2.

[1] http://en.wikipedia.org/wiki/Diatomic_carbon

> For example, a common idea is to introduce iron to the ocean. This would increase plankton populations, and the plankton would then use solar power to remove CO2.

I'm wary this leads to a "and now you have TWO problems" situation... presumably oceans full of plankton would do lots of other bad things too? Humans introducing plants/animals to control the populations of other plants/animals has worked spectacularly badly over the course of history (see: New Zealand).

> Incidentally, C2 is a strong acid

It’s almost impossible to produce a lot of C2 because it reacts with itself and produce some Carbon compound, like an amorphous version of graphite, similar to soot. In this version it can be compressed and buried.

(The main problem with this idea is that the decomposition needs a lot of energy.)

I would hope the long promised use of carbon in chips and synthetic diamonds would find a use for the carbon instead of burying it.

I was just wondering since it seems like we are not going to be able to reduce usage and undoing it seems like the only hope.

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