Ocean iron fertilization

Phytoplankton bloom in the South Atlantic Ocean

Since I spent my recess week researching on ocean acidification and ENV1202 essay on ocean iron fertilization, I think I should just share this with everyone. Ocean iron fertilization is the introduction of iron into the ocean to stimulate phytoplankton growth. As iron is usually the limiting factor for our oceans, this deliberate introduction can strongly increase phytoplankton growth, and as phytoplankton absorb carbon dioxide for photosynthesis, amounts of atmospheric carbon dioxide can be reduced. Hence, this technique of geo-engineering could be one way of reducing the amount of anthropogenic carbon dioxide from our atmosphere as well as mitigating ocean acidification. Despite the potential of iron fertilization, tampering with the environment may have severe and irreversible consequences that are largely unknown due to a lack of scientific research.

Through my research, I came across many articles talking about their results from small-scaled experiments and the detrimental effects that iron fertilization may bring. In this article ‘Can ocean iron fertilization mitigate ocean acidification’, possible consequences on the ocean that iron fertilization may lead to were mentioned, from analysis of results obtained through modeling studies. Some effects include the increase acidification of deep ocean, and the negligible effect on surface ocean acidification after many decades even though it may seem to be effective at the present, hence concluding that iron fertilization should not be carried out. Another article ‘A scientific critique of oceanic iron fertilization as a climate change mitigation strategy’ also does not support the use of iron fertilization due to the high cost and low efficiencies of sinking carbon into the seabed. Besides, the ecological impacts of altering the amount of available nutrients in our oceans and affecting the base of marine food webs could potentially cause damageable effects on our marine organisms, and the production of more potent greenhouse gases could worsen the state of our environment. Thus, with all these potential harmful effects, there are many scientists and researchers are against the use of iron fertilization. Of course, there are scientists that strongly support the use of iron fertilization, but I would leave those articles for interested people to research on! 

In my opinion, considering that reducing carbon emissions is taking too long for us to solely rely on to save out earth, possible techniques of geo-engineering such as iron fertilization could also be considered. I find this an interesting controversial topic to research on and after doing much research, I feel that since there is a potential for iron fertilization to remove atmospheric carbon dioxide in the long run, and more research should be carried out to determine its effects and we should not completely ban this technique at this stage. What do you think?

References

Allsopp, Michelle, David Santillo, and Paul Johnston. "A Scientific Critique of Oceanic Iron Fertilization as a Climate Change Mitigation Strategy." Greenpeace Research Laboratories, Technical Note 7 (2007): 2007.

Cao, Long, and Ken Caldeira. "Can Ocean Iron Fertilization Mitigate Ocean Acidification?". Climatic Change 99, no. 1-2 (2010): 303.