“Salting”, Or Is That “Ironing”, The Oceans

More ocean stuff, this time to do with CO2 … last week Nature published an article on results from a study that put iron-rich fertilizer in the ocean near Antarctica.

A team of oceanographers from Californian marine research institutes dropped 1.7 tonnes of iron sulphate in the sea as part of the Southern Ocean Iron Experiment in 2002. They then used floating robots to measure the carbon flux – and found that lots of biomass was indeed created and consigned to the depths of the ocean, either as dead algae or fish excrement.

Nature has also run a story in 1999 on how and why such an approach would work.

The ever-incisive Russel Seitz has a Tech Central Station article today on the research:

But for once, the initial margin of amazement belongs to the optimists. This observed ratio of return of carbon to iron-conservatively three orders of magnitude — is simply too large to ignore. Nobody in his right mind wants to bet trillions on carbon taxes given the uncertainty and trans-political time frame of the hypothetical impact of CO2 bracket creep, but downshifting the environmental ante from mind boggling fractions of M1 to mere hundreds of millions of dollars makes for a whole new game-one with real players instead of the usual crowd of shills and pigeons herded in by UNEP.

Paradigm shifts happen. Going from gigatons of fuel and CO2 to mere boatloads of iron fertilizer is a change so egregious as to compel hard thought all around.

This bears watching.


2 thoughts on ““Salting”, Or Is That “Ironing”, The Oceans

  1. Where do you get iron sulphate, what are the environmental implications of minining, transporting, dumping, etc. How much CO2 is produced doing so.

    It just sounds too good to be true, the Antarctic equivalent of ethanol.

    On the other hand, it may increase fish populations!

  2. Iron sulphate is a byproduct of smelting iron. It’s pretty cheap (from what I’ve heard) and takes less energy to produce than pure iron or pure sulfur. I think there’s a excess of the stuff these days, but I haven’t been able to find good numbers.

    The figures on carbon consumption seem genuine. First, the original researchers noticed a vast algae bloom when they first seeded a patch of ocean with iron sulfate. I gather this research backs those observations.

    Several issues come to me. Will repeated application of iron sulfate deplete other necessary minerals (eg, phosphorus) for algae growth? This technology isn’t so useful if we deplete (locally) minerals that take a while to replenish.

    How will we account for this as a carbon sink? We may enter the situation where agressive accounting of carbon sources and sinks is required.

    How pure does the iron sulfate need to be? What impurities are particularly undesirable? Repeated fertilization will result eventually in the presence of fish that can be commercially harvested (IMHO).

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