TCS Daily

Pumping Iron

By Russell Seitz - April 28, 2004 12:00 AM

If there are a lot of fish in the sea, it's because a plant-based food chain feeds them. One day there may be more -- brace yourself for the shock of good news about the environment. Fish stocks may rise and global CO2 levels fall in ways reflecting the capacity of sea water in mid-ocean to nourish plant and animal life.

What's true of sailors may apply to the sea. Once seamen perished of scurvy, because the vital role of vitamin C in nutrition went unrealized. Today, some parts of the oceans still languish as biological deserts because of chronic iron deficiency anemia.

There may be water, water everywhere out in mid-Pacific, but despite sunlight in dazzling abundance, often there's not a speck of iron to eat. Without this vital trace element, plant enzymes cannot form or function, and photosynthesis grinds to a halt. As the capture of carbon as biomass ceases, CO2 ends up in the air instead of the sea.

There is nothing new about this -- iron as a limiting factor in ocean biomass growth was recognized a century ago, and by 1990 the late oceanographer Brian Martin proposed the first of a series of small and large scale experiments in ocean fertilization that have continued since, growing in scope and controversy over the last decades.

The latest results, just published in Nature, respond to criticisms skeptics raised at the very idea of reducing atmospheric CO2 by raising the iron level of sterile expanses of cold salt water far offshore. It indeed appears that circumpolar waters that lack only iron run-off from the land might be turned into the equivalent of offshore national forests that sequester carbon in seas instead of trees.

Many greens screamed that the very idea was a snare and a distraction, diverting the world from the canonical solution of curbing energy consumption and taxing or rationing fossil fuels. It was one of the rare instances in which National Review, not The Nation, came to the fore as an early advocate of innovative intervention in curbing climate change -- the first experiments in the Pacific were hailed under the rubric 'Thar She Grows'.

Questions were raised as to what would become of carbon caught up in marine plant life when the phytoplankton died or was eaten, and it took years to even begin to answer them. But the scope and sophistication of the latest round of experiments has revealed that Martin's conjecture was sound -- a mere trace of iron dispersed in the biologically least productive waters of the open sea can unlock the treasure trove of and upwelling nitrogen, phosphate other natural nutrients that would otherwise go to waste and create a thriving community of microscopic plants and animals that can in turn support a burgeoning food chain.

A pound of iron in any form, from rusty bilgewater left behind in the wake of an aging container ship, to the deliberate spreading of fertilizer grade ferrous sulfate can yield new life enough to entrain anywhere from five to fifty tones of carbon. Arguments will rage as to whether ocean fertilization can span the eons between ice ages, or will run into some still undetermined biogeochemical limit in mere decades.

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.


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