So I was reading some of my notes from the past lectures and came across one of tangents we made about how scientists have thought about using plankton as a means for absorbing the carbon in the atmosphere. In our discussion, we went over how plankton could absorb the carbon dioxide in the atmosphere and alleviate global warming through depositing the carbon in the atmosphere to deeper levels of the ocean and the ocean floor.
I found this topic extremely interesting because I did a research project for the 2013 QuikSCience Challenge hosted by USC and studied phytoplankton and their potential to mitigate the effects of ocean acidification through their uptake of atmospheric carbon dioxide. Although my proposal was mostly theoretical, it did cover the discussion we had in class: plankton absorbs carbon in atmosphere and lowers the concentration of carbon dioxide, causing a lower amount of carbon dioxide to dissolve into the ocean and acidify the water.
I was interested in some of the negative ecological consequences of using plankton as a means of dampening the greenhouse effect since it seemed like increasing the amount of plankton in the ocean would have a significant affect on marine ecosystems. As it turns out, this use of plankton is a complicated issue. For one, increasing the amount of one type of plankton in the ocean may cause other plankton to die out and therefore reduce carbon dioxide uptake and defeat the purpose of adding plankton in the first place. An article I found talks about how small plankton tend to flourish with higher concentrations of carbon dioxide, but this significant blooming of small plankton led to a reduction in larger plankton species because the small plankton were taking up all the nutrients before the larger plankton.
In another article, a team of researchers discussed how plankton could potentially accelerate the rate of ocean acidification in deeper layers of the ocean, decrease oxygen concentrations in deeper marine ecosystems, and reduce the nutritional quality of plankton. They explained that these were due to the more rapid transport of carbon dioxide to deeper water levels, significantly more decomposition of biomass in the deeper marine ecosystems, and slower growth rates of organisms that fed on these "carbon-infused" plankton.
Check out the articles if you're interested!