GEO ENGINEERING: Iron Fertilization and its Dangers to the Oceans
- Category: Blog
- Date 18-08-2023
The Africa Climate Summit 2023 is coming to Nairobi and one of the agendas on the menu is climate engineering. In the past few decades, the question of climate change and how to mitigate it has been the basis of thousands of research papers, discussions, and ideas. One of the most exciting ones has been ocean fertilization or iron fertilization.
Iron fertilization is a geoengineering technique where iron is added (dumped) to certain regions in the ocean to stimulate phytoplankton growth. The idea is to use the microscopic phytoplankton as a carbon offset mechanism due to their use of Carbon Dioxide (CO2) in photosynthesis which makes them perfect absorbents of CO2 from the atmosphere as underwater carbon sinks. By promoting their growth through iron addition, it is theorized that they could absorb significant amounts of CO2 from the atmosphere, thus mitigating climate change effects. While this idea, in theory, is noble as a mitigation strategy, iron fertilization presents a lot of potential danger, especially with the limited knowledge that we have on the long-term effects of this process on the world’s oceans. Is it a pendulum that shall conserve with one swing and immediately slash and destroy with another?
Let us discuss a few of the potential effects it might have on the oceans and environment at large:
Unpredictable Ecological Effects: When high amounts of iron are introduced into the marine ecosystem, the natural balance of nutrients shall be disrupted. It is important to understand that while iron is very abundant on the earth’s crust, it is very rare in the oceans. So rare that while a liter of water contains 35 grams of salt, it has only a billionth of a gram of iron. This iron, when introduced to the marine ecosystem in large quantities shall mess around with marine food webs favoring the growth of some organisms at the expense of others. Large algal blooms have been observed to deplete oxygen underwater creating dead zones where marine and fish life cannot exist nor thrive. Iron fertilization poses the danger of depleting important nutrients to organisms on another zone of the ocean while favoring other organisms at a different zone. Phytoplankton are also harbingers of death and disease. Some phytoplankton species produce powerful bio-toxins which cause “red tides.” Red tides are harmful algal blooms that occur when large colonies of algae grow out of control and produce harmful effects on people, fish and marine organisms. Human illnesses caused by these blooms, while rare are fatal. Do we really want to phytoplankton to mass produce while the ocean water itself seems to have adapted to prevent this exact scenario?
Oxygen Depletion: These dead zones that are formed by algal bloom, scientifically known as hypoxia, are areas in the water that have reduced oxygen. They are formed when phytoplankton die and decompose. This decomposition consumes a lot of oxygen in the eutrophication process leading to the emergence of hypoxic (low oxygen) and anoxic (no oxygen) zones in the ocean which are essentially mass graveyards for organisms and fish which cannot survive in these zones.
The Carbon Cycle: Phytoplankton consume a lot of carbon, on a scale that is equivalent to forests and other surface plants. Some of this carbon that is captured is carried to the deep ocean when these organisms die and are transferred to different layers of the ocean when the phytoplankton are eaten by other creatures and a loop of carbon transfer is created through the marine food web and degradation upon death. It is somewhat similar to the way trees store carbon in their leaves, stems and branches and even timber when cut. A lot of carbon however gets released back to the atmosphere when phytoplankton (or species that eat them) die, not all of it is sustainably stored in the oceans. If large-scale iron fertilization is done, there could be unintended consequences in this carbon cycling loop potentially increasing the carbon released back to the atmosphere when these organisms die and decompose. We might find ourselves with higher carbon releases even than we have now, and this time, from the oceans. It could spiral out of control pretty fast.
The Marine Food Web: Phytoplankton form the base of the aquatic food web, if their populations are altered, the marine food chains shall be disrupted and lead to increased trophic levels, not only of the organism but also fish and other marine animals as changes in the availability of certain species of phytoplankton shall ultimately harm or increase the numbers of species that consume them as a primary source of food.
Ocean Acidification: The increased absorption of CO2 by the ocean, even if facilitated by iron fertilization, can lead to ocean acidification. When CO2 dissolves in seawater, it forms carbonic acid, which can harm marine organisms that rely on calcium carbonate to build their shells and skeletons.
Legal and Ethical Concerns: Iron fertilization raises significant legal and ethical questions. If this is allowed, it could set a precedent in manipulating natural processes and systems on a global scale. Scientists, governments and corporate alike would be encouraged to intervene in nature with zero regard to long term consequences. The process itself is carried out in ocean waters which are shared and transcend international boundaries, there are questions on who shall set the authority in manipulating these ocean areas and if in effects are felt on states that are not in agreement, how shall they be compensated? The United Nations Convention on Biological Diversity has placed a moratorium on large-scale ocean fertilization activities, and any attempts to conduct such activities would need to adhere to international regulations and guidelines.
Unintended Global Climate Effects: The complex interactions between the ocean, atmosphere, and climate system make it challenging to predict the full range of consequences that large-scale iron fertilization could have on regional and global climates.
In conclusion, while the concept of iron fertilization as a climate change mitigation strategy may sound appealing, it carries significant risks and uncertainties that make its implementation fraught with potential dangers to marine ecosystems and the environment at large. As researchers, environmentalists, and policymakers converge in Nairobi for the Africa Climate Summit from 4th of September to 8th September 2023, we all need to carefully consider these risks before attempting any large-scale interventions in the ocean. There have been a 50% increase in Marine Heat Waves over the past ten years and one of the causative agents has been increased acidification of the seawater. In order to effectively increase the capacity of the oceans to absorb carbon and excess heat from the planet, we need to protect ocean habitats in a sustainable manner and in ways that ensure millions of years of evolution of sea lands are not eroded by dangerous and untested scientific ideas. We should not be distracted from the root causes of climate change such as unsustainable development and deforestation. A reliance on techniques that seek to manipulate nature shall dissuade us from making the necessary systemic changes to improve our environment.