Carbon Credits vs. Insetting

May 31, 2024

One of the main questions I have been asked over the course of my PhD is, ‘Can we generate carbon credits from seaweed initiatives?’ This made me think that this is a topic worth exploring for this blog.

Currently, there are two seaweed carbon credits available: one focused on restoring wild seaweed forests in Western Australia and another in Japan.

The Western Australia initiative involves a kelp reforestation credit that incorporates a carbon credit from a globally recognised standard, making it an unconventional form of carbon credit. The other project in Japan is yet to be approved by other global standards. Currently, there are also two carbon credit proposals developed by the carbon methodology body Verra: one for carbon sequestration from seaweed farming and another for seaweed restoration. But after all this time researching seaweed, do I think seaweed should be used for carbon credits? Well it depends…

Current carbon credit methodology standards set a very high bar due to recent controversies in the international carbon market. Approval by one of the major international standards as a voluntary carbon credit takes a lot of funding and time. While the projects end up being of a high standard, the flipside of this is that a large portion of funds when carbon credits are purchased go towards administration and consulting for carbon credits. I believe that because of the many challenges with seaweed carbon accounting (measuring how much seaweed gets to the deep sea, testing nutrient competition with phytoplankton, etc.), seaweed carbon credits will be too difficult to implement with existing global standards. However, if a more pragmatic approach is taken in a similar way to the two existing seaweed carbon credit methods implemented in Western Australia and Japan, then carbon credits will be possible. 

Another way to recognise carbon removal from seaweed aquaculture is through insetting. This is where companies that are purchasing seaweed products pay a premium for their products because they can also claim the carbon sequestered by the seaweed in their company carbon budget. Importantly, robust traceability of seaweed products is required for this. Using insetting, carbon removal can be quantified and transformed into tradable products without having to jump through the same number of hoops that are required to register carbon credits. Insetting also helps to develop a robust and resilient supply chain by providing additional benefits to companies inside the same supply chain. Insetting is currently enabled by established globally recognised standards such as ISO 14064:1. However, some risks to insetting exist around guaranteeing no leakage, double counting and permanence. These criteria must be fulfilled for carbon credit projects but aren’t guaranteed under current insetting frameworks.      


At the end of the day, we all want the majority of funding to be channelled towards restoring seaweed forests and supporting communities that are farming seaweed. Seaweed projects must balance pragmatism and integrity in their methodology to be successful. However, it remains to be seen if the market will accept these types of credits at any scale. Carbon credits can help scale up seaweed restoration and seaweed aquaculture if we are willing to have a robust conversation about the compromise between integrity and impact in seaweed carbon accounting.

About the Author:

Finn Ross is a final year PhD candidate at the Blue Carbon Lab researching seaweed as a natural climate solution. He is a proud champion of climate action and is a vocal thought leader in the sustainability sector. Finn is also on several boards including the scientific board to the Kelp Forest Foundation, Future Farmers New Zealand, Climate Action Company and the Otago Department of Conservation.