Remix clone Hacker News

The flow and distribution of nutrients in the ocean follow weak gradients from their underlying sources in a kind of thermodynamic equilibrium. Some areas will have nutrient excesses based on geography, geochemistry, and limitations on consumption rate due to dependencies on other nutrients.

If iron is the rate limiting ingredient, then when you seed an area with iron a bunch of other nutrients are consumed in the process that currently are not being consumed. This changes the chemical equilibrium driving those other nutrient flows in the ocean and may stop critical nutrients flows into areas that rely on them. Any major local change to nutrient balance changes the equilibrium and thermodynamic gradients of the entire system.

In hindsight this is kind of obvious. There are similar equilibrium problems in large chemical reactors too and the ocean is just a giant reactor vessel to a first approximation. I think the original assumption was that the ocean is so big that no one would notice but long distance effects on local nutrient balances were observed such that increased sequestration productivity in one area was at least partially offset by losses of productivity in other areas due to new nutrient bottlenecks.

In principle modeling the entire system would allow one to inject the right nutrients at the right handful of spots to maximize aggregate sequestration performance with minimal risk. Building such models is still very much beyond us.

▲ ksec 4 days ago | parent | next [-]

Sorry about a naive question. If additional nutrients causes imbalance due to taking nutrients from other areas. Cant we add those nutrients in as well?

I am starting to think China will be the first to experiment with this in large enough scale.

	▲	ruined 4 days ago \| parent [-]
		theoretically yes, but this draws you away from the original objective of effective sequestration

▲ spwa4 4 days ago | parent | prev | next [-]

Wouldn't this only be an effect that happens on a small scale? It means that you'll see large changes elsewhere from small blooms in the ocean because of depletion elsewhere. Ok. But that cannot occur if you do this to an entire ecosystem (which can be the ocean, sure, but perhaps doing it to a large lake first would make more sense.

Second aren't we already doing large scale iron fertilization of the oceans? Not "intentionally" but simply rivers with human economic or residential activity along them.

	▲	staplers 4 days ago \| parent \| next [-]
		`aren't we already doing large scale iron fertilization of the oceans` Usually the opposite actually. Dams impede a massive amount of sediment from flowing into the oceans. Most large rivers near humans have multiple dams at this point.
	▲	mystified5016 4 days ago \| parent \| prev [-]
		It's kind of too obvious to notice, but the ocean is largely contiguous and interconnected. Any "local" effect can be distributed clear across the planet by ocean currents in a matter of days.

▲ 1W6MIC49CYX9GAP 4 days ago | parent | prev [-]

How does consumption of a nutrient stop its production?

	▲	chii 4 days ago \| parent \| next [-]
		It's not stopping the production, but changing the flow. suppose there's a flow of nutrients of type A from area one to area two. Currently, iron is the chokepoint in nutrient consumption of A, so that A is never completely consumed while going from one to two. By adding excess iron into area one, or in the middle of the region between this flow from area one to two, you now have the possibility to consume A completely as iron no longer limits A's consumption. So what happens to area two's consumption of A, if it became more scarce? May be nothing - or may be you now have another choke point of resources that wasn't there previously, leading to a change. If you weren't sure if this change would occur, or dont know, perhaps adding iron to area one is not a good idea, until such outcomes have been studied and acertained first.
	▲	baruch 4 days ago \| parent \| prev [-]
		I only use my common sense here, but it doesn't stop the production it just prevents the transport from the source to the destination through the area that was previously iron deficient and couldn't use the fully the other nutrient which passed on to another area.