A new, potentially promising plan to mitigate climate change by sequestering atmospheric carbon deep within the oceans, known as Iron or Ocean Fertilization, has prompted quite a controversy. The idea behind this geoengineering feat is to enrich nutrient-poor ocean waters with iron, thereby promoting the growth of algae, which doubles as a source of carbon sequestration and food for phytoplankton. Phytoplankton, in turn, is an essential food item for krill a small shrimp-like creature that constitutes a major part of the diet of many ocean fish, penguins, and whales, among other ocean critters. The algae that isn’t consumed dies and sinks to the ocean floor, sequestering carbon for the next million years or so, or so the theory goes. Ocean fertilizing has the same positive effect as natural deep ocean upwellings where waters become highly productive with life, supporting some of the best fisheries on earth. The only difference is the source of the nutrients. For upwellings, nutrients come from the ocean floor; whereas, for fertilizing, it comes from the surface.
Last summer, Planktos, a San Francisco-based, bioengineering firm, founded by Russ George, quietly embarked on a mission to spread 100 tons of iron sulphate from a fishing vessel into the Pacific Ocean near British Columbia to test the viability of ocean fertilization. Craig McClain, over at Deep Sea News, has a good history and the pros and cons of this commercial proposition. While some are outraged at Planktos for proceeding purportedly in violation of United Nation rules and without greater review of the potential environmental impacts, the mission successfully spawned a plankton bloom several thousand square miles in size. Appears like Planktos opted for the “better to ask forgiveness than permission” approach, which has angered some in the scientific community.
There is good reason to proceed with caution, however, because of the law of unintended consequences. Plus, the precautionary approach is a decidely conservative response, particularly when dealing with changes bounded by uncertainty. In some cases, too much of a good thing can be a bad thing. For example, excessive nutrient loading and harmful algal blooms in some waters, such as the Chesapeake Bay and the Gulf of Mexico, have created dead zones caused by the depletion of dissolved oxygen below concentrations vital to sustaining fish and other sea life. Over the last two decades we have developed a greater understanding of the causes of these hypoxic dead zones, which involve factors vastly different than those areas where ocean fertilizing is being considered on a larger scale. Although more study is needed, at first blush, ocean fertilizing, with proper review and oversight, does not present the same environmental problems that plague eutrophic waters, which are already hypertrophic.
So, you ask, what are the implications for global climate change or saving the plant? As a self-professing climate-change skeptic, I’m always a bit reticent to weigh in on the topic of climate change and mitigation strategies, particularly given the limits of my own knowledge and understanding on an incredibly complicated matter. However, I’ve never been one to believe that by ignoring the very large gorilla in the room it will magically go away. So here goes nothing (or something).
In addition to reducing greenhouse gas emissions, it seems that ocean fertilization has great potential as another strategy for creating carbon sinks that can offset the production of CO2 from fossil fuel use. Other sink strategies include reforestation of grazing or marginal crop lands and re-injection of CO2 deep underground through carbon capture and sequestration, a/k/a CCS, early developments which I helped to oversee during my tenure at EPA. Assuming human-induced climate change is occurring, each strategy holds potential and promise as one piece of a larger puzzle toward mitigating the potential environmental impacts. So, rather than reject this newest strategy, ocean fertilization should be thougtfully evaluated and considered along with all other strategies. Hereto, it strikes me that the correct and conservative approach is to pursue policies that encourage multi-pronged strategies that hedge against worst case scenarios, as opposed to top-down imposed policies that place our future and proverbial “eggs” in one very costly basket.