TL: A CRITIQUE OF THE OCEAN-SURFACE FERTILIZATION CONCEPT SO: Jeremy Leggett, A&E Greenpeace International (GP) DT: October 2, 1992 Keywords: oceans carbon dioxide global warming greenhouse effect atmosphere greenpeace gp scientific research climate plants gp / INTRODUCTION Some scientists have suggested artificially promoting the productivity of phytoplankton as a method for sequestration of carbon dioxide, or enhancement of the so-called biological carbon pump. This they might do, in principle, in one of two ways: by adding soluble phosphate or iron to sea water. The ability of phosphate to promote biological productivity has long been known. The idea that adding iron can do the same thing comes from suggestions that phytoplankton growth is limited at high latitudes because concentrations of dissolved iron in seawater are low. Iron is needed, among other things, to make chlorophyll, and without chlorophyll the phytoplankton can't photosynthesize. THE PHOSPHATE METHOD Biological activity in the oceans has the net effect of binding phosphorous, nitrogen, and carbon into organic matter at ratios of 1:15:130. Accordingly, "a simple interpretation of this ratio suggests that adding phosphate to the ocean surface should remove CO2 from the atmosphere-ocean surface system in a molar ratio of about 130 to 1." (1) Whether or not this could be done in practice would depend on whether ecosystems could shift away from the 1:15 phosphorous to nitrogen ratio. Keith and Dolwatabadi, in a recent study funded by the US National Science Foundation, calculate that if the method worked in practice, the cost would be "medium": 40 cents per ton of CO2 removed. There would be potential benefits as well as risks, they conclude. The risk of eutrophication they saw similarly as "medium." The possible benefit would be increased productivity higher up the food chain. Their study, of a wide range of "geoengineering" options, led to the following conclusion: "Many geoengineering schemes are sufficiently low in cost relative to abatement or adaptation that cost is unlikely to be the decisive factor in choices about implementation. Instead, issues of risk, politics, and ethics may prove more important." THE IRON METHOD The first advocate of iron fertilization, John Martin of the Moss Landing Marine Lab in California, conducted experiments in a test-tube which suggested that Antarctic phytoplankton were iron- limited. He speculated that 900,000 tons of iron -one supertanker full - could cause as much as 6 billion tonnes of excess carbon dioxide to be removed from the atmosphere. (2) Irrespective of risk, politics and ethics, there are serious doubts as to whether the iron method could work. Tsung-Heng Peng of the US government's Oak Ridge National Laboratory, and Wallace Broecker of Columbia University, have modelled the effects of adding iron to the sea, including the long period of time high latitudes spend in darkness, and shown that "even if iron fertilization worked perfectly it would not significantly reduce the atmospheric carbon dioxide content." (3) Joos et al (10) have also examined the issue, and made estimates of the maximum possible effect of iron fertilisation. Using a well respected carbon cycle model they assumed that iron is continuously added to the phosphate-rich waters of the Southern Ocean, which comprise 16% of the world ocean surface. They found that after 100 years of fertilisation, the atmospheric CO2 concentration would be 59 ppm below what it would have been with no fertilisation, assuming no anthropogenic emissions are included in the calculation. However they concluded that such a large uptake of CO2 is unlikely to be achieved in practice, owing to a variety of constraints that require further study. They added that the effect of iron fertilisation on the ecology of the Southern Ocean "remains to be evaluated". Other scientists have questioned whether the iron- fertilization effect works outside the test-tube where it was first observed, and raised the potential of the method - even if it did work - to use up nutrients, with catastrophic impacts on fisheries. (4) Keith and Dowlatabadi profess that on the one hand the technique could decrease dissolved oxygen concentrations, allowing emissions of methane from seawater to increase (oxygen oxidises methane to carbon dioxide in seawater), but on the other, could boost fishery yields. They put the cost as "low" - 10 to 15 cents per ton of CO2 removed - and the risk as "medium." (1) THE RISKS The unknowns are so huge that the supposed "technological fix" risks potentially creating problems as great as the ones it is trying to solve. First, the problem of eutrophication. Might the phytoplankton, if successfully fertilized, then use up so much oxygen in the ocean water that the planktonic ecosystem was disrupted? Who could say. Much would depend on ocean circulation, something still very imperfectly understood in detail. The indicators from marginal seas are not encouraging. "Eutrophication seems to be happening at the mouths of almost all the world's rivers," concluded Science magazine in April 1990, reporting on an international conference on algal blooms and eutrophication. "The extra nutrients are often remnants of fertilizers. (5) Phosphates, in other words. Second, the problem of toxicity in the phytoplankton. The extent to which we would be playing ecological roulette by going ahead with artificial fertilization is truly alarming when you consider how little we know about toxicity in microorganisms in the oceans. One of the few oceanographers to have systematically studied toxic algae in the oceans, Don Anderson of Woods Hole, is far from alone in believing that the incidence of toxic algal blooms has been growing in recent years. He said recently that "previously unknown organisms, and organisms thought to be harmless, have just exploded." (6) As Science magazine put it, "new types of toxins are appearing and known algal killers are extending their reach to new regions of the world." (6) In Canada during 1987, for example, three people were killed by eating seafood contaminated with a poison traced to a bloom of diatoms (a type of phytoplankton) previously thought to be innocent of all toxicity. Some scientists attribute the alleged growth of toxic algae blooms, at least in part, to the increased amount of phosphate entering the oceans, and indeed such long-term monitoring projects as there are show simultaneous increases in phosphorous, nitrogen, and toxic algal blooms. (5,6) Other scientists, aghast at the dismal database from monitoring algae in the oceans, point to the need for much more basic research before even a basic understanding can be claimed. (6) There are other imponderables. Richard Dugdale and Frances Wilkerson, of UCLA, suggested that iron might favour the growth of larger, less digestible, phytoplankton cells, which could reduce the grazing rate, and that the iron could even have a direct lethal effect on grazers. (7) This, then, in the scarcely-understood environment in which experiments would be taking place. Experiment becomes something of a misnomer. A more apposite word would be "gamble." THE ATTITUDE OF SCIENTISTS INVOLVED IN THIS KIND OF WORK The scientists who propose these kinds of geoengineering schemes all do so saying "a lot more research is needed," or stressing - as Keith and Dowlatabadi do - that they are only talking about possible "fallback" strategies, i.e. strategies only to be contemplated if we find humankind finds itself in real trouble with global warming. As K&D put it, "the possibility of unpleasant surprises in the climate system justifies a more coherent (though not large) research program in order to define fallback options needed to make reasonable policy choices."(1) John Martin of Moss Landing, the iron - fertilization pioneer, puts it more graphically. "People say we are playing God. ...If we get to the situation where Bangladesh is under water and London has to install air conditioning, then people will say we have to do something about it." (8) While admitting that his iron fertilization idea is in the "theory stage," Martin has applied for funding for large-scale experiments. The concept, he said, "gets people excited and stimulates research." (7) Yet he has admitted that when he first made the suggestion, he was half joking. The April 1991 issue of "Discover" magazine reports him as saying "I got into this mess by shooting my mouth off." (11) There is a clear impetus in the direction of carrying out in-situ experiments. This was clear two years ago, after a US National Research Council meeting convened on the subject in Washington. Martin has said he hopes to take a patch of ocean, fertilize it and "see what happens." (7) There can be little doubt that marine scientists see this field as a potential gravy-train for research funding in hard times, without necessarily believing - or perhaps caring - whether the research can pertain to the real world. Note that Keith and Dowlatabadi conclude specifically that "the climate system is too poorly understood to allow quantitative assessment of risk."(1) Other scientists such as Joos et al (10), after considering the potential for CO2 sequestration, conclude that "the most effective and relatable strategy for reducing future increases in atmospheric CO2 continues to be control of anthropogenic emissions." A SUGGESTED RESPONSE FROM GREENPEACE That we should oppose these experiments as unnecessary, unethical, attempts to set up ecological roulette on a planetary scale. We could offer the following reasons: i. They are not needed, when we know the solutions to cutting carbon dioxide in the atmosphere lie in feasible emission- reduction. ii. The risks are demonstrably huge. The emission of greenhouse gases to the atmosphere is already an "uncontrolled experiment" Iron fertilization would be yet another global "uncontrolled experiment" tampering with one of the foundations of the planet's life support systems. iii. The risks would never be quantifiable and could irreversibly damage ecological systems. iv. Scientists could not reasonably extrapolate from small- scale experiments to large-scale experiments, much less to full-scale releases of iron or phosphate. v. The experiments would take scarce resources away from research into other, potentially benign, technological fixes, such as the improvement in efficiency of solar cells. vi. Scientific research should continue to focus on understanding the global climate system and not be diverted into these ad hoc "experiments". The potential counter to such a stance would be that the experiments would improve understanding of the carbon cycle, something which we couldn't object to. True, we could answer, in fact we would support more scientific research targeted directly at climatological unknowns, such as the Joint Global Ocean Flux Study (JGOFS), the World Ocean Circulation Experiment (WOCE) and other such programmes. We could acknowledge that the results of such research may well provide the means of understanding the implications of these biogeochemical "solutions". However we would actively oppose any experiment that was explicitly designed to promote a risky geochemical fix on the basis that it is an unacceptable and major ecological gamble. With the ready availability of renewable energy and energy efficient technologies such a risk would be an entirely unnecessary one. We would have to demand that any proposed experiment that looked like it was testing such an idea was subjected to careful examination. We would have to call upon scientists involved in this area to assist our assessments. We could refer to the point that Hanson and Lacis made when reviewing the solar-cycle climate connection (9) that the best current advice which can be given to policy makers is to reduce the magnitude of the current global experiment particularly through environmental action which makes good sense on other grounds (e.g. CFC cuts, tree planting), with much more funding to alternative energy sources. REFERENCES (1) D. W. Keith and H. Dowlatabadi, "A serious look at geoengineering." Eos - Transactions of the American Geophysical Union, v. 73, no. 27, p. 289. July 7 1992. (2) "Greenhouse effect may be ironed out," Daily Telegraph, 20 August 1990. (3) T. H. Peng and W. S. Broecker, "Dynamical limitations on the Antarctic iron fertilization strategy," Nature v. 349, p. 227. 1991. (4) P. Williamson and J. Gribbin, "How plankton change the climate," New Scientist, 16 March 1991, p. 48. (5) J. Cherfas, "The fringe of the ocean - under siege from land," Science v. 248, p. 163, 13 April 1990. (6) E. Culotta, "Red menace in the world's oceans," Science, v. 257, p. 1476, 11 September 1992. (7) "Iron fertilization enriches controversy," Eos, v. 78, no. 2, 8 Jan 1991. (8) "Cast iron way to beat greenhouse effect," Independent, 19 August 1990. (9) Hansen, J. E. and A. A. Lacis. (1990). "Sun and dust versus greenhouse gases: an assessment of their relative roles in global climate change." Nature. 346: 713-19. (10) Joos, F., J. L. Sarmiento and U. Siegenthaler. (1991). "Estimates of the effect of Southern Ocean iron fertilisation on atmospheric CO2 concentrations." Nature. 349: 772-775. (11) R. Kunzig, "Earth on Ice," Discover, April 1991, p. 55. ANNEX: RELEVANT EXTRACTS FROM THE POLICY OF GREENHOUSE EFFECT PROJECT General Principles: "1.3 Intentional or incidental modification of global or regional climate by artificial means through human activities must be prevented." "2.2 Greenpeace opposes: 2.2.1 'Geo-engineering' ideas which involve experimentation with the complex climatic system, with no guarantees of the outcome; /5 "Note /5 A number of 'geo-engineering' ideas have been suggested for reducing climate change, ranging from space mirrors to reflect sunlight, to placing iron in the oceans to stimulate the generation of CO2-absorbing phytoplankton. There are serious ethical, political and scientific problems associated with such an approach. Some of the options will, in effect, involve experimenting with the complex climatic system, with no guarantees on the ultimate outcomes. It is difficult to conceive of any experiments which would not entail significant risks to individual countries, regions or the planet as a whole, due to unforeseen side-effects. Though Greenpeace does not oppose research into these options, it believes that funding for action to reduce emissions must take priority.