Phytoplankton | Carbon removal technologies

Plankton that pumps CO2 from the atmosphere into the sea.

Marine ecosystems remove about 8.4 gigatonnes (85,000 air craft carriers worth) of CO2 each year. Phytoplankton (microscopic organisms) are responsible for a third of all photosynthesis on Earth, and provide about half of the oxygen we breath. These suckers are the earths biggest carbon removers and we should be doing more to support them.

What does Phytoplankton do?

Phytoplankton live in the upper layer of the sea and in all fresh water on Earth, they replicate so quickly that there’s a new generation of them almost every day. They take in CO2 from the atmosphere and light from the sun, they get themselves eaten by microbes, which are eaten by fish, who then poop them out and the carbon they have sequestered sinks to the bottom of the ocean for hundreds of years. They effectively pump CO2 from the surface to the bottom of the sea.

Phytoplankton consume ten time more CO2 each year than humans burning fossil fuels, however, the amount that gets buried depends on how productive the Phytoplankton is. In order to grow, replicate, and remove CO2 they need nitrogen, phosphorus, and iron, as well as light and CO2. In unproductive areas only about 1% of the carbon sinks, while in the most productive areas, 50% gets pumped to the deep.

Unfortunately, like everything else, the sea is being affected by Climate Change which is having a negative effect on Phytoplankton’s productivity. There’s a lot of science being done about how and why but suffice it to say - as the water gets warmer and more acidic, Phytoplankton don’t get as many nutrients.

Photo by CDC on Unsplash

Is Phytoplankton the solution to Climate Change?

It seems like a simple thing to invest in, right? If we can properly distribute nutrients across the ocean, we can engineer more productive Phytoplankton, and year on year they can remove more and more CO2 from the air and pump it to the bottom of the sea.

Well, yes, but getting, treating, and transporting those quantities into the middle of the ocean is costly. It’s difficult to get people to buy into geoengineering projects in general, never mind ones that don’t have any direct returns for the investor (only on the planet), and while initial results have shown promising results, the costs and impact of doing it at scale are not well understood. But there are people working this problem:

• AlgaSpring in the Netherlands product Phytoplankton

• YCombinator are funding startups to invest in this geo engineering problem

• MARPHYL Marine Phytoplankton Company Inc (a BCorp) are producing it and making it into a super food

Conclusion

Phytoplankton is one of the biggest carbon removers on the planet and we could be helping them to do much more. They produce 50% of our oxygen and can remove 10 times more CO2 than burning fossil fuels puts out. However, without the right nutrients they’re only 1% efficient. But they’ve been known to be 50% efficient at their most productive.

I’ve written before about the need to change the way we think about carbon removals and so I wanted to shine some light on some of the potential removals solutions that I know of that aren’t yet getting the right attention.

If you have any questions, more information, or noticed an error in this article please reach out and let me know.

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