Carbon credits for dumping iron into the ocean? The artificial plankton bloom may absorb some CO2 but how permanent is that? It would be nice to see some research on that.
What I find amazing is how controversial this is. If you can actually pull a significant fraction of CO2 out of the atmosphere and return it to the sea, why wouldn't you do that? It would seem to be potentially a huge weapon to wield against global warming and relative to other ideas is both actionable and hugely less expensive. And yet even modest experiments are fought tooth and nail.
Its a strange dissonance that conspiracy theorists love but I write up to a more generalized fear of change. It will be interesting to see how this one turns out.
Source: http://people.uncw.edu/szmanta/BIO%20585%20CoralReef%20Field...
As others note, not all plankton is created equal; just as in human bodies a balance between bacteria and fungi create healthy conditions, getting a dramatic boost to one kind of plankton may throw things out of whack far down the road.
Perhaps an iron-hungry form of plankton (or algae) suddenly gains a foothold in the region, depleting other nutrients and sunlight from the existing balance of critters. As the iron levels go back to baseline and the opportunistic plankton gets absorbed into the food chain, now the existing food base is gone, just as a huge population spike of higher-on-the-food-chain species is ready to chow down.
You see this sort of effect in gulf "dead zones" where fertilizer (iron sulfate is definitely fertilizer in this case) has killed the existing balance and will take many years to reverse.
That said, perhaps some good could come of this type of practice. It's too bad this sort of vigilante experimentation is the only kind that can go on- if scientific bodies would endorse more research on limited scales, we'd have a lot more data for the potential damage.
So what I don't get is when people propose even modest iron farming experiments they get the crap sued out of them or otherwise targeted. Why? Why not start small, measure, and move up? We're over fishing the ocean anyway, and nobody is doing anything about that. That is killing fisheries in the name of sushi. So why is this project so dangerous?
Its very curious. One of the risks of this investigation is success. Lets say we develop a way to moderate the CO2 content in the atmosphere to what ever level we want using iron (very abundant) and the oceans (also very abundant). Is that a horrible outcome some how?
(Because: http://en.wikipedia.org/wiki/Cane_toads_in_Australia . These are complex, poorly understood systems, and the results will almost certainly not be what you expected. This isn't engineering.)
Iron sulfate does indeed lack reproductive capability. But it attracts plankton, which is a wide category of organism - some plankton can reproduce.
It's a false dichotomy. There's probably a wide range of things we can do, and picking an option just because it happens to be there & feasible, regardless of evidence of merit, doesn't seem like a winning strategy.
Put another way, you could cut off your hand to treat an infected wound. It's "feasible." But is it anything remotely approaching the best way? Furthermore, what if it turns out that artificially seeding the ocean with plankton is approximately as disastrous for the health of the ocean?
If there are demonstrable benefits, then "do the benefits outweigh the risks" is something that we must consider. To categorically strike out broad classes of solutions because something might go wrong, without even considering the severity of the possibility, is to advocate inaction.
Any solution to this particular problem is met with this nonsensical "something non-descript might go wrong, so we better sit on our asses instead" mentality. What we should be asking ourselves is "What solution has both the greatest good/bad ratio, and can be scaled enough to actually solve the problem". Things are going to go wrong; to stop exploring a possibility as soon as we learn that something could go wrong is naive and if universalized will lead to our downfall.
But that's just it: we have no way to answer that question. We can't say if it's a good idea because we don't even know if it's even going to yield good results, let alone what cost those good results come at.
I agree that we won't hit on some perfect solution which has no trade-off. But making a decision without even knowing what trade-off you're making could actually make things worse! Imagine if this does approximately nothing substantial for climate change, yet it kills off a ton of species. Now we're on a planet with an destabilizing climate and a substantially more destabilized ecosystem.
High stakes cut both ways. You can win big by doing something bold just as you can lose even bigger or sooner. And having people unilaterally try out their pet theories seems like a recipe for disaster. They'll likely be long dead before the effects of their actions are realized anyway.
The attribute of non-replication doesn't equate to "safe for the environment".
Done over a large enough area, it can change more than just the CO2 levels in the atmosphere.
Primarily by grazing on phytoplankton, zooplankton provide carbon to the planktic foodweb, either respiring it to provide metabolic energy, or upon death as biomass or detritus. Typically more dense than seawater, organic material tends to sink. In open ocean ecosystems away from the coasts this transports carbon from surface waters to the deep. This process is known as the biological pump, and is one reason that oceans constitute the largest carbon sink on Earth.