One of the things that’s had far too little attention paid to it is the idea that we might be able to use some natural processes, or mimic some, rather, to extract CO2 from the atmosphere and thus sequester it. One that has been floated (sorry) is that we might seed the nutrient-poor areas of the oceans to encourage plankton growth. As Russell Seitz says today, there’s a new paper in Nature that shows that this could work very well.
There is cause for puzzlement in Nature’s treatment of the discovery that “Each atom of iron supplied from below pulled more than 100,000 atoms of carbon out of the atmosphere by stimulating plankton growth ” in ocean waters upwelling around Kerguelen, in the frigid Big South.
The reason for the puzzlement is that so far there have been at most 6 attempts to mimic this seemingly highly productive process, which really seems to be far too few to write off the possibility.
For example, (I’m a little out of date so these are rough numbers) iron ore costs around $100 a tonne and is in the range of 50-60% iron atoms, so let’s say $200 per tonne iron. If we can seed the dead parts of the oceans with only 1% of the efficiency found in nature, that means we can suck carbon (note, not CO2) out of the atmosphere at 20 cents a tonne.
OK, OK, this is just musing on a blog, but doesn’t it seem sensible to spend a few hundred thousand dollars perhaps checking this out?
A very quick back of the envelope number shows that at that 1% efficiency we could sequester all global CO2 emissions for the price of 5% or so of current Australian iron ore production. Or, given the size of modern ore carriers, perhaps 20 shiploads a year?
Yes, I know, completely absurd, but wouldn’t you like to actually find out?