Dec 8, 2021 - Energy & Environment

The oceans are the next frontier for carbon removal

Illo Ocean
Illustration: Aïda Amer/Axios

The global ocean is emerging as a promising target for carbon removal efforts, according to a new report.

Why it matters: It's now clear that removing and storing carbon dioxide, as well as reducing carbon emissions, will be necessary to avoid the most dangerous effects of climate change.

  • But using the oceans as a carbon removal platform will require first answering major scientific, legal and social questions.

What's happening: Axios received early access to a new report from the Aspen Institute, with support from the ClimateWorks Foundation, that details a strategy for fairly exploring the ocean as a possible carbon removal site.

  • We know the ocean can play a role in carbon removal efforts because it is already doing so — about 40% of human-made CO2 emissions since the start of the industrial age have been absorbed by the ocean, slowing the pace at which warming would otherwise occur.
  • Since the ocean takes up more than two-thirds of the planet's surface, there is far more room to try carbon removal projects than on land.

How it works: One possibility involves harnessing nature by planting mangrove forests and kelp that can pull carbon out of the ocean and store it.

  • Another option would involve fertilizing the oceans with dissolved iron, which stimulates the growth of phytoplankton that can feed on CO2 in the water.

The catch: "The nature of both governance and science in the ocean presents a lot of challenges to that scale of development that would be needed," says Michael Conathan, senior policy fellow for ocean and climate with the Aspen Institute's Energy and Environment Program.

  • Nations claim an exclusive economic zone (EEZs) — the territory where they can control living and nonliving marine resources — only for the 230 miles beyond their coastlines. EEZs often overlap, and further on lies the open sea, which has even fuzzier international governance.
  • "How do you manage those transboundary effects, where action taken in one state ends up affecting others?" says Conathan.

What's next: The Aspen report suggests clarifying national and international governance structures that need to be established before ocean-based carbon removal can move beyond the experimental stage.

The bottom line: "We want to take advantage of what the ocean can offer on carbon removal, but we don't want to do it in a way that compromises ocean ecosystems or somehow makes the problem even worse," says Conathan.

Go deeper:

Go deeper