To Save the Climate, Look to the Oceans | Hacker News Reader

To Save the Climate, Look to the Oceans

blogs.scientificamerican.com

91 pointsBender42 comments

It omits one of the very promising, but somewhat controversial methods of CO2 sequestration: https://en.wikipedia.org/wiki/Iron_fertilization

Even in the most optimistic CO2 reduction scenarios, we still need negative emissions that will offset existing CO2 or use-case where eliminating fossil fuels is not practical (e.g. airplanes).

I've read somewhere that this method is a non-starter, because the methane it produces more than offsets the carbon it sequesters. I'd love to be wrong, of course.

Whales play a crucial part in natural iron fertilization of oceans, because they go deep underwater to eat a large amount of krill, which are iron-rich, and deject near the surface, because they need to breathe. Their dejections fertilize the phytoplankton which lives near the surface. Because they need to move between deep and shallow water, and because they travel over large distances, whales act as nutrient pumps for the ecosystem.

Are you sure we don't just need them to talk to a giant probe ionizing our atmosphere?

Better to keep em around, just in case.

> Even in the most optimistic CO2 reduction scenarios, we still need negative emissions

I think this is something a lot of people miss and I'm not sure why sequestration as a whole is a controversial subject (well I don't think planting more trees is _that_ controversial, though there are nuances people aren't usually aware of). We don't just need to be carbon neutral, we need to be negative. Plus there are many industries that we have no neutral method, such as concrete and steel production. Most people think if we solve energy and transportation we solve the problem instead of only solving 60% of the problem.

The other important factor here is that emissions are the problem. If coal plants sequester 110% of their emissions, there's no problem (well... in terms of CO2eq). The fact that this is a controversial subject is odd to me because it seems like the fastest way to get carbon negative. Sequester coal and natural gas plants until we can switch to a fully green (or green + nuclear, depending on your country's/region's constraints) system.

But if we talk about energy + transportation only being 60% of the issue (and US + Europe only being 30% of global emissions) it becomes much more important to talk about getting to NEGATIVE emissions, not zero (plus this helps with the 40 year lag of CO2 and temperature). And for those saying that other countries should take up their share 1) do you want to make that bet? You've all worked on team projects. We can't force them. 2) How do you ask a developing country to choose between hospitals and green energy? They don't have enough for both and one clearly has a shorter return on investment in number of human lives saved. (We can pick on China though, they're rich enough that they don't have to choose, but US and Europe need to be picked on as well).

> I think this is something a lot of people miss and I'm not sure why sequestration as a whole is a controversial subject

One of the major reasons it's controversial is that it has been used as a distraction and a false promise. I.e. arguments of the form "we can continue to burn fossil fuels, because some magic future CCS technology will fix everything" are very common.

I mean to be honest, it isn't burning fossil fuels that's the (CO2eq) problem. It is the emissions they leave. The problem is emissions, not where we get the emissions from (argument restricted to climate). This does seem to be a missed point by many. The problems is emissions, not source. The reason we talk about sources is because they correlate to emissions.

I don't get your point. What do you mean? How can the problem be CO2 emissions but not the source of those emissions? Of course if we want to solve the CO2 emission problem we have to reduce it at it's source?

> How can the problem be CO2 emissions but not the source of those emissions?

Because the problem is emissions, not who creates those emissions.

What I'm saying is that if coal does so much sequestration that it in effect has negative emissions, this is actually better than solar which has a little emissions. This is because we care about emissions.

I'll make an analogy. Let's say we have two companies that output poison in their process. Company A produces 10000 units and company B produces 5 units. Company A shifts and now produces -10 units of poison and company B doesn't change. Initially company B is better but after the change company A is better because really all we care is about the poison being produced and not actually what the companies do. Because at the end of the day, our goal is less poison. That's the number that matters.

The article mentions power by wave energy. I could not tell from the article if this is real or hypothetical. It sounds like a good idea but I have not heard anything about this. That is a constant source of naturally occurring kinetic energy. I did find the following on Wikipedia:

https://en.m.wikipedia.org/wiki/Wave_power

As a Texan I heard a lot about potentially tapping wind energy from floating turbines off the Galveston coast but have not heard about this in practice while the wind farms in west Texas are exploding in volume.

https://en.m.wikipedia.org/wiki/Wind_power_in_Texas

There are converters at coast lines that are reality and being tested/used.[0] There are plans to install converters at the bottom of the sea to collect wave energy, but if my memory serves correct, there were concerns that this would slow down processes in the ocean and might lead to problems in its ecosystem.

[0]: https://www.marinetechnologynews.com/blogs/wave-energy-resea...

Wave power has been a pipedream since the 1970s; the problem is that water is too powerful and tends to destroy structures over time. As well as being corrosive and full of living things that cause "fouling". It's also not been very well funded.

Offshore wind turbines on the other hand are practically a mature technology, while getting larger and larger over time (improves efficiency). There's loads around the UK, although mostly fixed rather than floating. Floating is a less mature technology.

Perhaps it would work better in estuaries, with clean(er) river/fresh water. The ecological impact may be prohibitive, but as an engineering task it seems easier.

Extracting tidal power from estuaries is another similar pipe dream - people have been discussing building one in the Severn estuary for as long as I have been alive.

Tide power is intermittent but extremely predictable and not tied to the diurnal cycle, which would be advantages.

They've been successfully extracting power from the Rance estuary for over half a century.

The trouble with estuaries is that in addition to the ecosystem damage and change to flood dynamics associated with hydro power in general, they also tend to be used for ships to navigate, so getting a scheme which suits everyone is a major challenge.

Yes, there is so much untapped potential for wind and solar that at the current time it's pretty much pointless to spend R&D on unproven technology. We don't have the time to develop new methods for energy generation before we need to be mostly carbon neutral. For the same reason it doesn't make much sense to fund next-gen nuclear power. It just takes too long.

Perhaps the floating bit is the hold up. Extremely destructive hurricanes are a nearly annual occurrence in that area so the turbines must not be fixed and must be able to right themselves vertically after severe wind/waves. Otherwise they are not worth the investment.

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