Iron fertilization: Scientists want to add the element to the ocean to capture carbon
Adding metal to marine life


The climate is warming, and much of the increase is due to greenhouse gases, the most prevalent gas being carbon dioxide. Methods for removing existing carbon from the atmosphere are in the works, and some experts are arguing in favor of iron fertilization, a geoengineering approach which would help oceans trap atmospheric carbon. While the method has potential, the consequences of implementing it are still largely unknown.
Iron in the ocean
An article published in the journal Frontiers in Climate lays out a program for implementing iron fertilization to help fight climate change. Ocean iron fertilization (OIF) is a "technique where small amounts of micronutrient iron are released onto the surface of the sea to stimulate the growth of marine plants known as phytoplankton," said Euronews. "This rapid growth removes carbon dioxide from the atmosphere through photosynthesis. When the plankton die or are eaten, some of that carbon is captured as it sinks deep into the ocean." Geoengineering like OIF has long been in discussion as a way to mitigate carbon emissions.
"Given the ocean's large capacity for carbon storage … enhancing the ocean's natural ability to store carbon should be considered," Paul Morris, one of the authors of the study and the project manager for international experts group Exploring Ocean Iron Solutions (ExOIS), said in a statement. ExOIS wants to conduct iron fertilization trials to determine whether the technology could be implemented on a larger scale. "This is the first time in over a decade that the marine scientific community has come together to endorse a specific research plan for ocean iron," Ken Buesseler, the study's lead author and executive director of the ExOIS project, said in the statement. The program wants to raise $160 million for the trial and has already received a $2 million grant from the National Oceanic and Atmospheric Administration.
Subscribe to The Week
Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.

Sign up for The Week's Free Newsletters
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
Oceanic objections
Not everyone is on board with investing in iron fertilization. Many worry that "fertilization could create 'dead zones' where rampant algal blooms would consume all the oxygen in the water, snuffing out other life," said Scientific American. "Phytoplankton blooms could also consume nutrients such as phosphorus and nitrogen that then wouldn't be available for organisms elsewhere, a phenomenon known as 'nutrient robbing.'" There is little known about how iron fertilization will interact with other climate factors that affect marine life, like warming oceans.
In addition, iron fertilization may not be as effective at removing carbon as some experts claim. "Even at its peak performance, the technique just can't store that much carbon," Alessandro Tagliabue, an ocean biogeochemist at the University of Liverpool, said to Hakai Magazine. "Setting up a large-scale nutrient fertilization project would require mining the minerals and building infrastructure to get them into the ocean. These activities would emit carbon, lowering the overall carbon sequestration potential by the time the nutrients hit the water."
However, some sacrifices could be necessary to ensure progress. "It's a small change in biology, relative to doing nothing and watching this planet boil," Buesseler said to Scientific American.
A free daily email with the biggest news stories of the day – and the best features from TheWeek.com
Devika Rao has worked as a staff writer at The Week since 2022, covering science, the environment, climate and business. She previously worked as a policy associate for a nonprofit organization advocating for environmental action from a business perspective.
-
6 peaceful homes near small towns
Feature Featuring doors with local topographical maps in Oregon and a 1850s homestead-turned-house in Vermont
-
What would happen to Earth if humans went extinct?
The Explainer Human extinction would potentially give rise to new species and climates
-
The best TV shows based on movies
The Week Recommends A handful of shows avoid derivative storytelling and craft bold narrative expansions
-
Melting glaciers may lead to more volcanic eruptions
Under the radar We're in for a boom
-
Europe's heatwave: the new front line of climate change
In the Spotlight How will the continent adapt to 'bearing the brunt of climate change'?
-
How carbon credits and offsets could help and hurt the climate
The explainer The credits could be allowing polluters to continue polluting
-
This Atlantic hurricane season is expected to be above average
Under the radar Prepare for strong storms in the coming months
-
Why men have a bigger carbon footprint than women
Under the Radar 'Male identity' behaviours behind 'gender gap' in emissions, say scientists
-
Why the weather keeps getting 'stuck'
In the Spotlight Record hot and dry spring caused by 'blocked' area of high pressure above the UK
-
The worst coral bleaching event breaks records
The Explainer Bleaching has now affected 84% of the world's coral reefs
-
Why UK scientists are trying to dim the Sun
In The Spotlight The UK has funded controversial geoengineering techniques that could prove helpful in slowing climate change