Seeding the oceans with nano-fertilizers could create a big, much-needed carbon sink. Credit: Illustration by Stephanie King | Pacific Northwest National Laboratory
Iron-based fertilizers in the form of nanoparticles have the potential to store excess carbon dioxide in the ocean.
An international team of researchers led by Michael Hosela of the Pacific Northwest National Laboratory suggests that using microorganisms could be a solution to the urgent need to remove excess carbon dioxide from the Earth’s environment.
The team conducted an analysis published in the journal Nature’s NanotechnologyPossibility of seeding oceans with iron-rich engineering fertilizer particles near marine plankton, important microflora in marine ecosystems, to increase phytoplankton growth and carbon dioxide uptake.
“The idea is to augment existing processes,” said Hosila, a lab fellow at the Pacific Northwest National Laboratory. Humans have fertilized the land to grow crops for centuries. We can learn to fertilize the oceans responsibly.
Michael Hosela is an internationally recognized environmental geochemist. Credit: Virginia Tech Photo Services
In nature, nutrients from the land reach rivers and oceans by blowing dust to fertilize plankton. The research team suggests taking this natural process a step further to help remove excess carbon dioxide from the ocean. They analyzed evidence that adding specific combinations of carefully crafted ingredients effectively fertilizes the oceans, encouraging phytoplankton to act as carbon sinks. Living organisms absorb large amounts of carbon. Then, when they die, they absorb the excess carbon and sink to the ocean depths. Scientists say the proposed fertilization could speed up a natural process by which carbon has already been safely sequestered from the atmosphere into a form that can be removed for thousands of years.
“At this point, time is of the essence,” Hosela said. “To combat rising temperatures, we need to reduce carbon dioxide levels globally. And exploring all of our options, including using the oceans as carbon dioxide sinks, offers the best opportunity to cool the planet.
Extract insights from the literature
In their analysis, the researchers argued that engineered nanoparticles offer several attractive properties. Highly controllable and custom tuned for different marine environments. Surface coatings help the particles stick to the plankton. Some particles also have light-absorbing properties, allowing plankton to consume and use more carbon dioxide. The general approach can be adapted to meet the needs of specific marine environments. For example, one area may benefit more from iron-based particles, while silicon-based particles are more effective in others, they say.
The researchers’ analysis of 123 published studies showed that several non-toxic mineral oxygen products can safely promote plankton growth. They argue that the stability, abundance of soils, and ease of formation of these materials make them viable options as plankton fertilizers.
The team also studied the cost of developing and distributing the different particles. While this process is much more expensive than adding non-engineered materials, it can be very effective.
Reference: “Potential Use of Engineered Nanoparticles in Ocean Fertilizers for Large-Scale Removal of Atmospheric Carbon Dioxide” Peyman Babakhani, Tannabon Fenrat, Mohammad Balocheh, Galapa Surada, Caroline L. Peacock, Benjamin S. Twining and Michael F. Hosila Jr. November 28, 2022 Nature’s Nanotechnology.
DOI: 10.1038 / s41565-022-01226-w
Besides Hosila, the team included researchers from the United Kingdom, Thailand, and several research institutes in the United States. The study was funded by the European Research Council under the European Union’s Research and Innovation Program Horizon 2020.