[spqr0a1]

Unfortunately this sort of mining has long-term impacts on deep sea ecology. It causes substantial loss of species diversity and activity even 26 years later, with this paper estimating recovery will take at least 50 years for a small test patch. https://www.science.org/doi/10.1126/sciadv.aaz5922

[elil17]

Things are a little more complicated than that.

1. Surface mining also has environmental consequences which have to be weighed against the costs of deep sea mining. An area impacted by surface mining can recover in just a decade, but it takes intensive environmental restoration efforts on the part of humans (https://news.ucsc.edu/2021/05/mine-remediation.html). If similar techniques could be developed for deep sea applications, it could reduce the impact of deep sea mining.

2. Researchers are developing robots with advanced propulsion systems which could dramatically reduce the disturbance to sea-floor sediment by mimicking the ways that rays move. (https://interestingengineering.com/culture/new-autonomous-su...) Of course, this is still an active area of research, and it would probably take regulation to force deep sea mining companies to adopt these measures.

3. Nodules are much easier to process, reducing the carbon footprint of deep sea mining vs. surface mining by up to 80% for some metals. (https://www.sciencedirect.com/science/article/pii/S095965262...) This study even tries to account for the secondary effects of mining such as the different impacts that surface and deep sea mining have on carbon sequestered in the ecosystem.

4. Surface mining is more harmful to humans than deep sea mining is because it can leach dangerous chemicals into fresh water supplies. (https://www.usgs.gov/special-topics/water-science-school/sci...)

The effects of deep-sea mining on ocean ecology are much less well understood than the effects of surface mining. While I do think there's good reason to be optimistic about the benefits of deep-sea mining, especially if it can displace surface mining, we shouldn't assume we understand what will happen. I hope the industry continuous to be forced by regulators to move forward cautiously and allow time for environmental studies to take place.

edit: These people are trying to build a deep sea miner that doesn't destroy the seafloor: https://impossiblemetals.com/

[ulrashida]

Sea floor mining is widely ridiculed by both environmental and mining professionals as having more risk than equivalent and better understood efforts on land. At least its close cousin, space mining, has the benefit of taking place off planet. I hope we never see this activity occur commercially in our lifetimes: we barely have gotten a handle on surface and underground mining, why do we run off to scrape the ocean as well?

On 1: The study you have referenced refers to the difficulties of remediating historical abandoned sites, often run under inadequate regulations typically in the 1850's - 1960's. Modern sites are no joke to remediate, but regulators are beginning to pick up on what causes problems to occur and how to ensure these costs are factored into the mining operation. The difficulty of applying effective regulations to international undersea areas is enormous.

On 2: That's great -- lots of things could happen to improve technology in both terrestrial and submarine mining.

On 3: Carbon footprint is not everything when determining the appropriateness of mining. The study cited by the Science article assumes tailings deposition at sea -- mines are not permitted to do this. The article also swans repeatedly over how "high grade" nodules are, but makes no direct reference to their actual grade. The underlying paper suggests a grade of 1.3-1.4 weight percent which is on the bottom end of mid-grade.

On 4: This point can not be concluded without further study. While terrestrial mining has had more historical impacts to humans, this does not allow for comparison on future terrestrial mining vs. a relatively unknown ecosystem impact from aquatic mining. Mining is also not assessed on purely anthropocentric impacts. We've begun to appreciate that systems are interconnected and humans are only one receptor. Enormous caution is required, certainly more than "lower emissions = good".

[elil17]

I'm not sure that sea floor mining is widely ridiculed. I've seen it taken about as seriously by grantmakers as other emerging technologies. That said I’m not in the mining space.

I'm don't disagree with your points - there's a lot of uncertainty around all of this research. But, from what I can see, regulators are doing the right thing and being very cautious to do environmental studies at each step of the way. Maybe I'm way off about that.

[orbital-decay]

>Surface mining also has environmental consequences which have to be weighed against the costs of deep sea mining.

What will actually happen is both types will be happily used at the same time, so there's little point in weighting one against the other.

Any other rationalization misses the fact that this is an extremely poorly understood environment (especially if we do compare with surface mining). It's never a good idea to tinker with unknown at scale without understanding it first, let alone commercializing it. Mining history is practically written in mistakes like that.

[culi]

Right. Especially as we ramp up our reliance on solar panels (and therefore batteries). These operations are now heavily subsidized and we'll likely be making 100% use of every avenue available to mine as much as possible as soon as possible

sigh. If only we put this much funding into solving our exploding e-waste crisis which could also help alleviate the problems of rare metals

[elil17]

I don't think it's true that both will be used at once - if deep sea mining is cheap enough, it could make surface mining non-viable. A carbon tax could certainly eliminate surface mining because smelting surface minerals uses so much more energy compared to smelting nodules.

We actually put much more funding into e-waste recycling. Allseas most recent funding round was $150m, and they're the only major player in the deep sea mining space. But Redwood materials, one of many e-waste recycling startups, has raised $700m in their most recent round.

[jeffbee]

We don't need weird elements to support solar with batteries. Grid stabilization can do fine with lead-acid batteries. Both lead and sulfur are readily available. There are also iron batteries and other emerging battery chemistries, as well as non-battery storage like pumped liquids or pressurized gases.

[Robotbeat]

Don’t need manganese or any rare minerals for batteries. Lithium iron phosphate batteries are used in the least expensive Teslas (base Model 3 and Y), and although lithium is very abundant, you can even substitute it for the even more abundant Sodium with only a slight weight increase. That’s superior to Lead based batteries in nearly every way.

[pfdietz]

Manganese is not a rare mineral. One does not mine manganese nodules for the manganese. Mining them would create an enormous surplus of manganese that would get dumped in waste piles.

[arcticbull]

Or you can reduce your need for batteries by combining wind and solar with green, safe nuclear reactors - and smart grids capable of varying their demand instead of us trying desperately to adjust supply.

For example, as more folks move to electric cars, a smart grid would allow chargers to charge less at periods of intense demand.

We've historically focused exclusively on adjusting supply to meet demand - which is clearly very difficult and very expensive (especially if you look at gas peaker plants) - but we instead (or in addition) can adjust aspects of the demand curve to smooth out variability in load. This should be easier and significantly cheaper.

[s1artibartfast]

Great, if we don't actually need the metals then there will be no one to buy them from the deep sea Miners and the problem will solve itself

[hedora]

Alternatively, keep burning fossil fuels, but overproduce renewables on average, and use the waste energy for carbon capture.

(This has the big advantage of buying time to decarbonize things like concrete, cattle and airplanes.)

[Schroedingersat]

1kg of Lithium in an LFP battery provides diurnal storage for about the same amount of power as 1kg of Uranium can produce, lasts 3x as long, is recyclable, and mining the lithium is less harmful.

[burnished]

You still need batteries to support the solar and wind systems. If making the grid responsive to total load increases efficiency then hell, let’s do both

[Schroedingersat]

Abundant battery chemistries are already most of the way through commercialisation. ZnBr, Sodium/Prussian blue, Iron flow, and Iron air are all proven practial and rapidly scaling. AlS, NaS and LiS are hopeful next steps.

The only critical mineral not yet eliminated for the most commercially viable upcoming option is silver which requires about one ounce per net kilowatt with state of the art processes.

Unless you meant cheap energy will subsidize mining, in which case you are correct and this is a problem.

[cgh]

Point 4 is mostly confined to old abandoned sites, as mentioned in your link. Modern tailings aren’t left to leach acid all over the place, at least not in North American mines. I get that all bets are off in eg Africa, however.

[elil17]

Sure, but a lot of surface exploitation is planned globally. Africa and Asia are certainly going to be seeing new mines opening due to demand for solar/batteries.

[cgh]

For sure, I was taking issue with the absoluteness of the assertion that all terrestrial mines are leaching from their tailings piles/ponds. It’s not true of many (most?) modern mines.

[elil17]

I didn’t mean it as an absolute assertion, but I can see that I didn’t make that clear.

[legulere]

The nodules themself offer a habitat with its hard crust compared to the soft sea-floor. As it takes millennia for the nodules to form this means the habitat for those organisms is basically lost.

[stubish]

I wonder how large a patch we could mine over 50 years, and if it is a meaningful fraction of the ecosystem? The planet is almost covered with deep sea ecology. Plumes and water contamination could significantly increase the affected area, which I'd hope for these studies to be watching for.

(how much affected by drag net fishing might give a ballpark figure)