How seawater might soak up more carbon | Hacker News Reader

How seawater might soak up more carbon

nautil.us

39 pointsdnetesn17 comments

There is no way to get out of this without carbon capture. We already have too much carbon in the atmosphere, even if we reach net zero. And a lot of that extra carbon in the system was buried before being pumped up as fossil fuel.

Said so, we won't survive the death of the oceans. And that is what is the worst that can happen meddling in scale with them, if even because we don't know yet all the players there. We are still getting surprised by unexpected interactions, new feedback loops, new things and new ways of things going wrong. Could be (existing or emerging) process that reemits that "captured" carbon, so the effort may be short lived or kick back badly. And meddling without knowing the consequences is not (geo)engineering.

Most net zero proposals (and this carbon capture "solution") doesn't put in the map severely cutting down extraction, just moving that carbon around the system in a potentially transitory way, and keeping adding new fossil carbon because capturing something will be flagged as a green card to keep business as usual.

Why can’t we live with something like 450ppm?

It's not about living with xxx ppm, it's about sustainability and pleasantness of the ecology.

How is the ecology more sustainable and pleasant with a different amount of CO2 than 450ppm?

What is the optimal concentration of CO2 and why?

If you start tinkering with things you aren't sustaining it, you're tinkering with it.

Increased in CO2 requires ecological adaptations of organisms living in the oceans, for instance. https://www.noaa.gov/education/resource-collections/ocean-co...

"Researchers have already discovered severe levels of pteropod shell dissolution in the Southern Ocean, which encircles Antarctica."

The optimal concentration for the ecology that we recently had is the CO2 concentration we had a bit before that (as it takes times for effects to be felt). Plus or minus, here or there, depending on other factors such as warming.

Forcing the rest of the ecology to try to adapt to increased CO2 levels starts to become really problematic for them when we are also forcing them to try to adapt to things like human-introduced invasives, human-caused habitat destruction and repurposing, population loss due to over-hunting and over-harvesting. It all adds up.

Good point about OA. I couldn’t find what the control was in the pteropod study. What are they comparing them against?

Also looks like OA isn’t uniformly bad. Some species seem to thrive: https://www.whoi.edu/oceanus/feature/ocean-acidification-a-r...

> Good point about OA. I couldn’t find what the control was in the pteropod study. What are they comparing them against?

No clue. I was just using it as an example.

> Also looks like OA isn’t uniformly bad. Some species seem to thrive

Sure, that's why the harm is measured in terms of entire ecologies, not individual species.

The optimal is whatever it median value was before industrialization. Not that Earth hasn't had life at a wide range of CO2 levels, but current life had a million+ years to get used to mid-200s PPM, whereas we've gone from that to over 400 in a few decades. Ecologically, that's like hitting a brick wall. The rate of change is too fast.

It is not a photo, it is not a closed room. We are in a system, that have inputs and outputs. With more than GHG (not just CO2) than preindustrial times, the planet keeps more energy of what it receives to the sun. That affects the pretty complex system that is the climate one, in several ways, and triggering several positive feedback loops that makes things even worse (i.e. losing ice over ocean means less albedo, and more energy capture, whatever is the concentration of CO2 in the atmosphere). And some of those feedback loops even do their own emissions of GHG, like more methane from wetlands, and the one emitted by permafrost thawing, potentially more water vapor that is a strong GHG, and so on.

There is a point where the concentration of CO2 is directly harmful for human beings, 450ppm is still far from that. But having too much for too much time put the system on a roll into a direction that we don't want. And we are not decreasing it, but still accelerating the rate at which we emit it.

We are already meddling with the oceans, by putting more CO2 in them (by way of the atmosphere). The first method described in the article works by directly removing that CO2 from the oceans. It reverse the meddling we've already done.

Then it puts the carbon in calcium carbonate, which can lock it up for millennia.

Millenia like in with trees, that a forest fire can return it to the atmosphere in a whim? How stable are those calcium carbonates regarding how the oceans can change on temperature, acidity or even life, to name just a few factors?

And it should be able to address more than this (https://elements.visualcapitalist.com/the-scale-of-fossil-fu...) amount of carbon yearly (and that is not the volume of the calcium carbonate, but the source carbon, it could be far bigger).

Keeping the fuel underground is the best capture technology. It will keep being safely there unless a suicidal species dig around for retrieving and burning it.

There's no need to put the calcium carbonate back in the ocean. Calcium carbonate is limestone. The White Cliffs of Dover are limestone, and they've been there for millions of years.

Keeping the fuel underground would have been nice. Now the CO2 level is already too high. As you pointed out above, we have to stop emissions and pull CO2 back out of the atmosphere.

> nearly 1,800 full-size factories on coastlines

Good luck manufacturing those in a carbon-neutral way.

There are no hacks. We need to stop emitting so much of this stuff.

Who is going to pay for those factories that net-reduce emissions by 1/4? what about pouring those fund into avoiding emissions in the first place, like replacing coal plants with something green or not building new ones or not burning down rain forest or getting people to not commute for 3 hours a day in their SUVs or flying intercontinental for a week of beach holiday?

Sadly, stopping emissions isn't enough anymore.

Sadly, we're not going to achieve even that much. We will not only fail to hit net zero, we will still be increasing year on year long after that point.

Net zero was always hard, harder than anyone would actually admit. Because what actually needs to be done is even harder than that. Thus far we have accomplished fuck all and will continue to achieve fuck all.

Yes the ocean can absorb a bunch of carbon, and in doing so you get acidification - wiping out coral and crustaceans, both of which are critical parts near the base of ocean ecology.

There is no magic get out of jail free card other than reducing carbon emissions to levels significantly below current, and then likely waiting thousands of year for some degree of stabilization. People talk of carbon sequestering but that needs to not just compensate for the current emissions, but the last 50-100 years of such - given no project is talking about volume sufficient for just what we’re still emitting I don’t hold out much hope.

Acidification is due to the water holding more carbon dioxide (carbonic acid) than baseline, right? This proposal is to turn carbonic acid into calcium carbonate, which 'removes' the carbonic acid from the water. So this would reduce acidification (at least until the water absorbs more carbon from the atmosphere). Am I missing something?

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