Climate change is a hot-button topic that is sure to  spark arguments between those who believe the climate is changing and those who believe it’s not, or at least that if it is, it's due to natural processes. Researchers around the world are researching ways to address climate change, some well-known and some controversial . One controversial  idea states that seeding the ocean with dissolved iron could help stave off climate change. Is this a legitimate possibility, possibly more harm than good, or just a shot in the dark?

The Theory of Geoengineering

The concept of seeding the oceans with dissolved iron is a form of geoengineering — the practice of human beings deliberately intervening with the natural environment. When it comes to climate change, this is usually split into two categories — actions used to mitigate solar radiation and actions used to help remove carbon dioxide.

Seeding the ocean with iron would fall under carbon geoengineering, specifically the practice of ocean fertilization. Basically, scientists add nutrients to the ocean to encourage and bolster the local ecosystems.

How does ocean fertilization work?

Iron for Phytoplankton Growth

Seeding dissolved iron into ocean water encourages the growth of some of the smallest organisms in the ocean — phytoplankton. These microscopic ocean plants help reduce carbon dioxide. How? Just like their land-based counterparts, they process the CO₂ it into oxygen.

A lack of necessary nutrients — specifically iron — in the water often limits phytoplankton blooms. The addition of iron to the water supply encourages these organisms to bloom and grow, taking as much carbon dioxide out of the atmosphere as they can before they die.

How does phytoplankton differ from other plants? It doesn’t release the carbon dioxide it absorbed. When the individual cell dies, it simply sinks taking all the CO₂ collected throughout its life with it down to the ocean depths.

Small-scale iron seeding tests have thus far shown limited results, and larger-scale tests have generated a lot of controversies. A new study, published in January 2016, found the introduction of iron to the ocean to encourage phytoplankton growth may not pull as much CO₂ out of the atmosphere as was previously thought.

Geoengineering Controversy

The biggest problem with geoengineering is the unknown. While researchers may have a basic understanding of the ecosystems around the world, they don’t completely understand the impacts of their experiments in the long run. It’s nearly impossible to predict what impacts geoengineering programs, like seeding the ocean, could have in the future.

It also doesn't help that ocean fertilization is a fairly new concept. Scientists only recently started conducting research and experiments within the last 10 years or so. In such a short amount of time, long-term impacts are difficult to determine, which is why large-scale experiments are being called pollution rather than a potential savior.

Geoengineering could potentially be an invaluable tool that will help us prevent — or at least help stave off — climate change. However, it will require more study to fully assess the widespread environmental impact of these techniques.

Ocean fertilization might be a useful tool for helping us reverse the effect of climate change — “might” being the key word. We simply don’t know enough about the long-term effects of this technique to employ these on a large scale. There is always the problem of phytoplankton blooms causing issues with fish populations, for example. With the completion of more studies, we’ll gain a better understanding of effective geoengineering strategies. Then, we can determine which are safe enough for widespread use and help reverse the effects of climate change.