What do you think of iron fertilization?

I am not a big fan of the idea. Systems are complicated and inter-related in ways that are poorly understood, and the consequences of significantly changing biological activity in an area are difficult to anticipate with certainty. You would be messing with the mass flux of much more than iron in performing the "fertilization" and this will undoubtedly create a depletion in some important constituents downstream from the location, among many other possibilities that are difficult to predict quantitatively.

I don't like the idea of large-scale experimentation in the natural environment without having a very good prior handle on the many possible or likely impacts of said experiments, and that is what we would be doing. The problem intended to be addressed does not seem to be so horrible that action with large uncertainty is warranted at the moment.

That is, probably not a good idea and not really needed anyway, as far as I can see.

Let us be clear: Iron fertilization is a means to sequester (remove) as much of the carbon from burning fossil fuels as desired. And doing so cheaply, easily and quickly. No matter what your position, this should interest you.

http://en.wikipedia.org/wiki/Iron_fertilization

How does it work? Iron is not very soluble in ocean water and is commonly a deficient nutrient there. Adding iron causes microscopic plants to multiply. The plants absorb carbon and a significant number sink, sequestering the carbon on the ocean floor. This is what happens when iron gets added naturally. Nor is this just theory. Every part has been observed as natural processes or as experimental results. The overall method has been observed both ways.

Amazingly a number of people are all exited about a recent experimental result that allegedly left oxygen depleted zones. It was as if they'd never heard of eutrophication:

http://en.wikipedia.org/wiki/Eutrophication

Just add the iron more diffusely and you'll get results in line with the over a decades worth of more positive observed experimental AND natural results. Since this is an imitation of a natural process, either the "dead zones" are an avoidable abnormality or not significant to the environment. Take your pick. If you will read the article Jeff M provides the link to, you will see my answer is the same the hypoxia article gives.

If you don't see this, or disagree, by all means comment. Jeff M, if your complaint of being blocked is toward me, it is unintentional and unknown to me. (As you say, I am new here. Try using comment, if that wasn't what you meant.)

Given that what amounts to a total solution to AGW, if it is needed, has been known since the late 1980s, the list of experiments and their dates is eye opening. Were a solution actually sought, every possible experiment would have been made, every question answered, years before the last century ended. Don't take my word for it. Look and think for yourself.

Iron is deficient in many parts of the open ocean. Increasing iron would increase plankton and would be a good way to increase krill production. I am skeptical that it would reduce CO2 more than just a marginal amount because the pertinent carbonates are quite soluble in cold water where the fertilization would likely take place. If you fertilized the south Atlantic, for example, you would certainly temporarily increase the life in that water and it would take some CO2 but after that it would be a net zero CO2 reduction. If you could have some of the life precipitating carbonates on the ocean floor, maybe it might reduce CO2. I have a geologist friend who thinks it is crazy to propose such drastic measures. I think it has some merit as a potential way to increase the production from the ocean but I would recommend caution since everything seems to have unintended consequences.

To address the dead zones, these are typically created in very warm water. I don't think it would be an issue in the colder waters where Fe fertilization would likely occur. There really is a lack of life there now and the waters are quite oxygenated. With Fe available, certainly that life would increase and O2 might decrease in certain places and perhaps deep in the ocean where the new life precipitates but I doubt it would be that much but it might be one of the unintended consequences if my doubts are unfounded. Lynlions, mineable iron is readily available IMO. for example, laterite soils without any processing would be perfectly suitable IMO and they are mostly iron oxides. You are certainly correct however that it would have to done over and over again because that iron would only last for a short time.

I think it may be potentially useful, in some small degree, if used with caution. Though I think its utility will have more to do with correcting for previous overfishing by enriching marine food webs than as a cure-all for global warming.

I suspect doing enough iron fertilization to entirely correct AGW would 1. involve more iron than we could reasonably afford to mine, 2. have unintended consequences, and 3. cost a lot more than things like reducing our overall reliance on fossil fuels.

Amazingly a number of people are all exited about a recent experimental result that allegedly left oxygen depleted zones. It was as if they'd never heard of eutrophication:

http://en.wikipedia.org/wiki/Eutrophicat...

I think this would be an excellent idea if you happen to "have the hots" for an iron maiden. On the other hand, maybe sinking all of the military operation naval vessels (tanks and military aircraft too), this might help move us to world peace.and to end the stupid and endless wars in Central Asia.

It could be a good idea, it could increase the fertility of the sea.

However I do not like geo-engineering, we humans have a tendency to screw up.

As I believe increased CO2 levels are not a problem, I would rather not try it.

I did see another idea, long tubes with one end floating, fitted with a one way valve to allow water to rise up but not sink, powered by the up and down wave action, this had the result of bringing up nutrient rich water from down deep, however the experiment failed as the tubes were too fragile and broke up after a short period, however during the short period many schools of fish formed so it must have been working.

I'd like to see a study that reports on the relative effect versus correcting overfishing, especially fishing near the bottom of the food web (e.g.krill). Restoration of seagrass ecologies would also be of great interest.

I will start with what I think of geoengineering in general. I think that geoengineering should only happen as a last resort; only if bad things, such as the flooding of millions of square miles of land, actually happen because of global warming. I am against using geoengineering as an excuse not to develop clean energy sources. And should Raisin Caine chime in, if he is right about things like sea level rise and drought not to be things to worry about, then there should be no geoengineering.

But, as far as iron fertilization is concerned, from what I have heard about experiments is that it is not very effective at removing carbon dioxide from the air.

This is what happens when people start to become aware that serious mitigation efforts should have been in place 30 years ago. Now there is a rising sense of urgency that will induce some people to want to take drastic measures and with unknown consequences. This could become a serious issue when a more stressed nation takes its own initiatives towards Geo-engineering.

Iron fertilization of the oceans has some serious downsides that need to be considered. One of them is the amount of iron needed over a large area of the oceans. http://www.whoi.edu/page.do?cid=886&ct=162&pid=977...