What is it?
A set of geoengineering proposals to grow large swathes of plankton by dumping nutrients into the ocean. The plankton is supposed to draw down carbon dioxide. In reality this technique doesn’t appear to work and threatens marine ecosystems.
Oceans play a key role in regulating the world’s climate. Phytoplankton (microorganisms that dwell on the surface of the ocean), despite their minute size, collectively account for half of the carbon dioxide absorbed annually from the Earth’s atmosphere by plants. Through the process of photosynthesis, plankton capture carbon and sunlight for growth, releasing oxygen into the atmosphere. The world’s oceans have already absorbed about a third of all carbon dioxide (CO2) humans have generated over the last 200 years. According to NASA, about 90% of the world’s total carbon content has settled to the bottom of the ocean, mostly in the form of dead biomass.
Proponents of ocean fertilization posit that dumping “nutrients” (generally iron, nitrogen or phosphorous) in waters identified as “high nutrient low chlorophyll” (HNLC) – i.e., where there are low concentrations of phytoplankton due to the absence of one nutrient – will spur the growth of phytoplankton. Since phytoplankton use CO2 for photosynthesis, the idea is that increasing the population of phytoplankton will increase CO2 -absorption. They argue that when individual phytoplankton die (the lifespan of phytoplankton is short – a few days at most), they will fall to the ocean floor leading to the long-term sequestration of carbon at the deeper levels of the sea. The goal of commercial enterprises engaged in ocean fertilization is to profit from selling carbon credits or offsets for the sequestered CO2 through voluntary or regulated carbon markets.
Phytoplankton populations in the world’s oceans are declining as a result of climate change and warmer water temperatures. The amount of iron that is naturally deposited from atmospheric dust clouds into the global oceans (providing nutrients for phytoplankton) has also decreased dramatically in recent decades. According to NASA satellite data, as water temperatures increased from 1999 to 2004, the ocean’s microscopic plant life dropped significantly. Oceans around the equator in the Pacific saw as much as a 50 percent drop in phytoplankton production. Advocates of iron fertilization schemes believe that iron is the missing nutrient that will restore phytoplankton and sequester two to three billion extra tonnes of carbon dioxide every year – roughly one-third to one-half of global industry and automobile emissions. Some regions of the ocean (especially near the Arctic and Antarctic circles) are nutrient-rich but anemic – they lack sufficient iron to stimulate plankton growth. With the addition of iron in these presumably otherwise healthy zones, scientists hope to increase plankton growth thereby increasing the absorption of CO2. However, U.S. and Canadian scientists, writing in the journal Science, point out that “the oceans’ food webs and biogeochemical cycles would be altered in unintended ways.” They warn that if carbon trading schemes make it profitable for companies to engage in ocean fertilization, “the cumulative effects of many such implementations would result in large-scale consequences – a classic ‘tragedy of the commons.’” Others note that iron may not be the ocean’s only nutrient “deficiency” – researchers have identified silicate as a crucial component in carbon export, for example – but each “correction” to ocean water composition could have unintended effects.
There are both commercial and scientific ventures involved in ocean fertilization and at least 13 experiments have been carried out in the world’s oceans over the past 20 years. A 2007 experiment near the Galapagos Islands by U.S. start-up Planktos, Inc. was stopped because of an international civil society campaign (See example, below.) The company was already selling carbon offsets on-line and the company’s CEO acknowledged that its ocean fertilization activities were as much a “business experiment” as a “science experiment.”
Climos, another U.S. start-up in the field, is still operational. The CEO of Climos has proposed a “code of conduct” for ocean fertilization experiments to “find effective ways for the science, business and carbon market communities to collaborate.” The Ocean Nourishment Corporation, an Australian company run by Ian S.F. Jones with ties to the University of Sydney had plans to dump urea (nitrogen) into the Sulu Sea but was stopped by the Filipino government in 2007, after over 500 civil society organizations campaigned against the plan. The science of ocean fertilization is increasingly discredited, with experimentation receiving negative reviews from everyone from the Royal Society to the New Scientist, not to mention the Inter-Governmental Panel on Climate Change.
The 191 governments attending the Convention on Biological Diversity adopted a de facto moratorium on ocean fertilization in May 2008. The London Convention and Protocol on ocean dumping has also addressed the issue, and are trying to establish how to define a legitimate scientific experiment.
What’s wrong with Ocean Fertilization?
Phytoplankton are the foundation of the marine food chain. Iron may well stimulate the growth of algae blooms but its potential to capture and eliminate any significant amount of carbon is doubtful at best. The list of potential side-effects is long: oxygen depletion (anoxia) in the deep sea; disruption of marine ecosystems, particularly the food chain; a strong likelihood of increased releases of other GHGs such as nitrous oxide and methane as well as gases such as DMS that form clouds altering weather; potential toxicological impacts such as dinoflagellates in the case of urea fertilization; potential worsening of the problem of ocean acidification. Ocean fertilization could also have devastating impacts on the livelihoods of people who depend on healthy marine systems, most notably fisher folk.
Example– The Planktos Story
Planktos, Inc. was a U.S. start-up company that intended to sow the oceans with iron in order to create plankton blooms that would theoretically sequester CO2. By early 2007 Planktos was already selling carbon offsets on its web site, claiming its initial ocean fertilization test, conducted off the coast of Hawaii from the private yacht of singer Neil Young, were taking carbon out of the atmosphere. In May 2007, Planktos announced plans to set sail from Florida to dump tens of thousands of pounds of tiny iron particles over 10,000 square kilometers of international waters near the Galapagos Islands, a location chosen, among other reasons, because no government permit or oversight would be required. In efforts to stop Planktos, civil society groups filed a formal request with the U.S. Environmental Protection Agency to investigate Planktos’s activities and to regulate them under the U.S. Ocean Dumping Act. In addition, public interest organizations asked the Securities Exchange Commission to investigate Planktos’s misleading statements to potential investors regarding the legality and purported environmental benefits of their actions. Hit with negative publicity, Planktos announced in February 2008 it was indefinitely postponing its plans because of a “highly effective disinformation campaign waged by anti-offset crusaders.” In April 2008, Planktos announced bankruptcy, sold its vessel and dismissed all employees. It “decided to abandon any future ocean fertilization efforts” due to “serious difficulty” raising capital as a result of “widespread opposition.”