Almost three decades ago, at a conference at the Woods Hole Institute, oceanographer John Martin said with “a half a tanker of iron…I will give you the next ice age.”

Martin was referring to a process now known as ocean iron fertilization (OIF) that he hypothesized could create vast amounts of phytoplankton. By literally dumping iron into certain regions of the ocean, called high nutrient, low chlorophyll zones, he suspected one could create vast plumes of phytoplankton that would absorb CO₂ from the air, like their plant brethren on land, and convert it to energy, cooling the atmosphere.

Between 1992 and the present day, several actors have tried to promote OIF under the international climate change regime. However, proponents have been stymied by the advocacy efforts of a network of critics, drawn from the research and NGO communities. These critics argue that OIF is part of a controversial and dangerous set of climate governance mechanisms known as geoengineering.

As I explore in a new Global Environmental Politics article, the fact that advocates have been able to successfully oppose a process that seems to present such clear material incentives illustrates how the language we use to describe problems can shape our understanding of their dimensions, including their significance and their risk.

Against Geoengineering

In the years after Martin’s presentation there were concerted efforts by proponents in the science, corporate, and government sectors to create a system legitimizing ocean iron fertilization as a climate governance mechanism. By the early 2000s, they argued that OIF could allow states with carbon offset obligations to meet them cheaply. For example, Michael Markels, founder of GreenSea Ventures, claimed he could sell credits at $2 per ton in comparison to the $20 per ton price from land use processes being discussed within the UN Framework Convention on Climate Change.

Not coincidentally, such a scheme would have provided millions of dollars to GreenSea Ventures and other agencies selling OIF credits. However, OIF’s most vociferous opponents were a coalition of oceanographers and members of environmental NGOs, like Greenpeace and the ETC Group, who charged it was part of a scientifically and ethically dubious constellation of practices known as geoengineering.

In short, geoengineering refers to large-scale environmental interventions that “use or affect the climate system (e.g., atmosphere, land, or ocean) globally or regionally and/or…cross national boundaries.” For critics, geoengineering comes with a specific set of flaws that make it more problematic than other kinds of environmental intervention.

First, geoengineering is portrayed as a “gamble” with the Earth’s ecosystems. Since most geoengineering proposals are so large scale – sometimes planetary scale – the consequences for getting something wrong are immense. Their scale also makes it difficult to properly test concepts and proposals because there is no Planet B.

Second, geoengineering is structurally problematic. It presents a solution to the climate change crisis that does not depend on changing our underlying behavior. Rather than cutting emissions, we can continue to pollute and use geoengineering to save our skins. But what about other emissions besides carbon dioxide, critics point out. What about the fact that extracting fossil fuels brings additional environmental harms, such as deforestation, land loss, and local air pollution? What about the second and third order effects of more phytoplankton in the oceans? And would OIF have to be implemented more or less forever? The likelihood of unforeseen consequences down the line is high.

Third, geoengineering is undemocratic. By design, geoengineering proposals are supposed to have global effects. If the technology becomes available to states or private actors, there is a real possibility that just a few people could interfere with the climate unilaterally.

Uncertainty as Risk

Crucially, these storylines meant that opponents of geoengineering – and ocean iron fertilization itself, as it became more closely association with the concept – became more likely to interpret uncertainty as an indicator of risk. The effect of this framing can be seen in a string of OIF-related actions.

For example, in 1999, Greenpeace issued a report to the London Convention on maritime pollution and dumping warning that OIF could, among other things, transform planktonic communities and disrupt marine food webs. In 2001, Sallie Chisholm, Paul Falkowski, and John Cullen from the Department of Oceanography in Canada published what became one of the most widely cited articles on OIF, raising “great concern” about the “potential long-term consequences” of OIF, including its “purposeful eutrophication” of ocean ecosystems.

In 2007, Planktos, a firm started by budding geoengineer Russ George, attempted to conduct an OIF experiment off the coast of Ecuador. Greenpeace blockaded the experiment, forcing George to call it off. In the aftermath, the International Union for Conservation of Nature called on the international community to oppose OIF out of a concern that it would alter “the nature and function of the ocean marine food chains” and increase the production of other greenhouse gases. Greenpeace and the ETC Group also submitted a recommendation to the London Convention arguing that OIF created the “potential for unpredictable and irreversible adverse impacts on marine ecosystems.”

In a 2008 conference at the Woods Hole Institute, critics like oceanographer John Cullen noted: “How many ecological manipulations that were done with the greatest of intentions had unintended consequences?…Can we know when it’s going wrong? I would argue that we can’t.”

In 2012, George launched another experiment, this time successfully dumping 100 tons of iron off the coast of Canada. This precipitated a plankton bloom approaching 10,000 square kilometers. While George insisted he had the support of researchers and indigenous groups in Canada, the media, environmental groups, and oceanographers condemned him. In 2012, The New Yorker described George as a “geo-vigilante” and concluded by stating that even if a local village approved, “no village on earth should have the power to approve a project the consequences of which, for the entire planet, cannot possibly be foreseen.”

A Pitfall?

As the dialogue around ocean iron fertilization shows, language can have a powerful effect on how international society responds to emerging environmental problems. Prior to 2007, firms used the iron hypothesis to argue that international society should legitimate the sale of credits from OIF. In response, environmental NGOs and oceanographers stated that OIF was geoengineering, and as a result, uncertainty should be taken as an indicator of potentially severe harm.

Ultimately, OIF critics have successfully pushed the international community to implement a moratorium. In 2008, the Convention on Biological Diversity issued Decision IX/16, which argued that iron fertilization should “not take place until there is an adequate scientific basis on which to justify such activities.” The London Convention issued Resolution LC-LP.1, which cited Decision IX/16 of the CBD and stated “ocean fertilization activities other than legitimate scientific research should not be allowed.” In 2013, the Convention passed Resolution LP.4(8), reiterating that all ocean fertilization activities except for scientific research “shall not be permitted.” At the time of writing, international society has continued to reject the commercialization of OIF.

At this point, ocean iron fertilization is not known to be either objectively good or objectively bad; it exists in a state of uncertainty. The norms underlying what to do about geoengineering projects have encouraged cautious application of this technology – if any at all.

However, relying so much on uncertainty to underpin anti-geoengineering arguments may have unforeseen consequences itself. If climate change becomes severe enough, the international community’s moral calculus may shift, as the uncertainty of a geoengineered world is seen as less catastrophic than the certainty of a climate changed world. Critics will then have a much harder time arguing against its eventual application. With that in mind, it might be best to establish a framework for geoengineering governance now, rather than at a time of crisis.