Plankton boost salvation? Credits wanted for ocean-urea-sprinkling: plot is $10 to $15 per cost per tonne of CO2 abated; cheaper than $50t cost of CO2-dumps
Posted by gmarkets on 20 September, 2007
According to Ian Jones, head of the Ocean Technology Group at the University of Sydney, Australia, and director of the Ocean Nourishment Corporation (ONC) the way to make money from carbon credits at lowest-cost was ocean-urea-sprinkling. In May this year, 350 miles north-west of the Galapagos Islands, George’s company, Planktos, based in Foster City, California, began the first of six large-scale trials to release more than 50 tonnes of finely ground haematite into the ocean, reported New Scientist (15/9/2007, p.43).
Boost plankton numbers; cut carbon emissions: The company aimed to show that fertilisation with iron can safely boost levels of phytoplankton – single-celled photosynthetic organisms responsible for half of the carbon fixation on Earth. More of such plankton, Planktos reasons, means the ability to trap more carbon dioxide from the atmosphere, which will help combat global warming.
Iron deficiency: Iron seeding was based on the well-accepted idea that plankton growth in the equatorial Pacific, the Southern Ocean and the north Pacific was restricted by low levels of iron. The concept was first proposed in 1990 by John Martin, then director of the Moss Landing Marine Laboratories in California. Since then, 12 international experiments in these waters have shown that adding iron can cause plankton to bloom, increasing the amount of CO2 drawn into the surface of the ocean.
Nitrogen boost works in Australia: By contrast, in sub-tropical ocean regions such as the waters off Australia, nitrogen, rather than iron, is the main brake on plankton growth. Researchers there were experimenting with seeding the ocean with nitrogenous fertiliser. Now, though, private companies were getting in on the act. They were keen to talk up the benefits. George maintains that iron seeding should be seen as “remediating” the oceans, restoring what some say are falling plankton levels.
Aussie urea release plan: Ian Jones, head of the Ocean Technology Group at the University of Sydney, Australia, and director of the Ocean Nourishment Corporation, (ONC) intend to release 1000 tonnes of urea off the coast of the Philippines later this year. He says that more plankton will ultimately mean more fish, and fewer hungry people.
Carbon credit cash chase? Critics argue that talk of ocean remediation or boosting fish stocks is simply window dressing and that these groups are racing not to save the Earth, but to carve out a slice the booming market in carbon-credit trading. ” These are very much business projects, not research projects,” said Philip Boyd at New Zealand’s National Institute of Water and Atmospheric Research in Dunedin. “Planktos, for example, views the ocean as a simple, predictable system that can be readily manipulated. The bottom line of the manipulation is that it’s all about carbon offsets and carbon credits.”
Seeding cheap as chips: Ocean-fertilisation projects were particularly attractive as they could be cheaper than alternative methods, such as renewable energy sources or carbon capture and storage. Urea fertilisation, for example, would cost $10 to $15 per tonne of CO2 sequestered, Jones estimated, whereas George reckons iron seeding could be done for as little as $4 per tonne. By comparison, carbon capture and storage from coal-fired power stations could cost $50 per tonne of CO2.
But does ocean-seeding actually work? That assumes, of course, that ocean seeding will work – something that has yet to be shown, according to Boyd. In a review of iron-seeding experiments in February (Science, vol 315, p 612), Boyd and his colleagues found that the amount of carbon drawn into the ocean’s surface layer varied widely. One study, which involved adding 1.1 tonnes of iron, found no increase in carbon fixing, but it was conducted in the autumn – possibly too late for plankton to bloom. Another found that 35o kilograms of iron boosted plankton levels sufficiently to fix an extra 1250 tonnes of CO2 – 250 times the average British citizen’s annual emissions. It sounds good, but it’s not enough. T9 lock carbon away for the long term, the plankton has to die of natural causes and sink to the deep ocean, where the carbon may be trapped for hundreds or thousands of years.
Difficult subject to research: None of the 12 iron-seeding experiments in Boyd’s review showed that adding iron increased the amount of plankton reaching the deep ocean. Part of the problem is that it’s very difficult to measure sinking carbon. Recent studies, though, have made some progress.
New Scientist, 15/9/2007, p. 43