Carbon Trading: Is It a Scam?
Few environmental policies have generated as much debate as carbon trading. To its supporters, carbon markets provide a financial incentive for businesses to reduce greenhouse gas emissions and invest in climate-positive technologies. To its critics, they have become a mechanism that allows large corporations to purchase carbon credits instead of addressing the environmental impacts of their own operations.
The reality lies somewhere between these two positions.
Carbon trading is not inherently a scam. At its core, it is simply a market mechanism that assigns an economic value to reducing or removing greenhouse gases from the atmosphere. Whether that market delivers meaningful environmental outcomes depends entirely on the quality of the carbon credits being traded and whether they represent genuine, measurable, and long-term carbon sequestration.
One area where carbon markets show genuine promise is marine aquaculture.
Seaweed cultivation naturally absorbs carbon dioxide from seawater through photosynthesis, converting dissolved carbon into biomass while helping to reduce local ocean acidification. As the oceans exchange carbon dioxide with the atmosphere, this process also contributes to reducing atmospheric CO₂ concentrations. The rapid expansion of seaweed farming throughout Asia has been driven not only by these environmental benefits but also by growing demand from the food, cosmetics, pharmaceutical, agricultural, and biotechnology industries, demonstrating that climate-positive industries can also be commercially successful.¹
Shellfish farming provides another example of natural carbon capture. Mussels, oysters and other bivalves construct their shells from calcium carbonate (CaCO₃), locking carbon into durable biological structures. Global shellfish aquaculture now produces approximately 13.6 million metric tonnes of shell calcium carbonate every year, creating a renewable material that can substitute for minerals extracted through mining. Instead of being discarded as waste, shells can be recycled into agricultural lime, construction materials and other industrial products, further supporting the principles of a circular economy.²
These industries provide environmental services beyond carbon sequestration. Seaweed absorbs excess nutrients, helping to improve water quality, while shellfish filter large volumes of seawater, removing suspended particles and supporting healthier marine ecosystems. Together, they can be integrated into Integrated Multi-Trophic Aquaculture (IMTA) systems, where the waste produced by one species becomes a resource for another, reducing pollution while increasing productivity.³
This raises an important question. If a seaweed or shellfish farm is demonstrably removing carbon, improving water quality, creating habitat, and producing food, should those environmental benefits have an economic value?
Many would argue yes.
The challenge is ensuring that carbon credits represent real environmental outcomes rather than accounting exercises. Some carbon offset projects have been criticised for relying on uncertain calculations, temporary carbon storage, or activities that would have happened regardless of financial incentives. In these cases, carbon markets risk becoming little more than a licence to pollute.
Marine aquaculture offers an opportunity to move beyond this criticism. Unlike many offset schemes, the benefits are tangible and measurable. Farmers produce physical biomass, improve coastal ecosystems, generate employment, and create products with genuine market demand. Carbon sequestration becomes only one part of a wider portfolio of ecosystem services rather than the sole justification for the industry.⁴
From the perspective of Circular Stream, the real question is not whether carbon trading itself is a scam, but whether we are rewarding the right activities.
A carbon market that simply enables businesses to continue polluting while purchasing questionable offsets has limited environmental value. A market that rewards industries for restoring ecosystems, producing sustainable food, recycling waste into valuable resources, and permanently removing carbon from the atmosphere is something entirely different.
Carbon trading should not replace sustainability;It should reward it.
References
- N. Ahmed et al., ‘Can Greening of Aquaculture Sequester Blue Carbon?’, Ambio, 46.4 (2017), pp. 468–477; T. Waters, R. Jones, H. Alleway, R. Gentry and A. Xu, Analysis of Farmed Seaweed Carbon Crediting and Novel Markets to Help Decarbonize Supply Chains (2023).
- A. A. Alonso, X. A. Álvarez-Salgado and L. T. Antelo, ‘Assessing the Impact of Bivalve Aquaculture on the Carbon Circular Economy’, Journal of Cleaner Production, 279 (2021), 123873; J. P. Morris, T. Backeljau and G. Chapelle, ‘Shells from Aquaculture: A Valuable Biomaterial, Not a Nuisance Waste Product’, Reviews in Aquaculture, 11 (2018), pp. 42–57.
- T. Chopin, J. A. Cooper, G. Reid, S. Cross and C. Moore, ‘Integrated Multi-Trophic Aquaculture: What It Is, and Why You Should Care… and Don’t Confuse It with Polyculture’, North American Journal of Aquaculture, 70.2 (2008), pp. 139–158; M. Troell et al., ‘Ecological Engineering in Aquaculture—Potential for Integrated Multi-Trophic Aquaculture (IMTA) in Marine Offshore Systems’, Aquaculture, 297.1–4 (2009), pp. 1–9.
- Ahmed et al.; Alonso, Álvarez-Salgado and Antelo; Waters et al.
Bibliography
Ahmed, N., Bunting, S. W., Glaser, M., Flaherty, M. S. and Diana, J. S., ‘Can Greening of Aquaculture Sequester Blue Carbon?’, Ambio, 46.4 (2017), pp. 468–477.
Alonso, A. A., Álvarez-Salgado, X. A. and Antelo, L. T., ‘Assessing the Impact of Bivalve Aquaculture on the Carbon Circular Economy’, Journal of Cleaner Production, 279 (2021), 123873.
Chopin, T., Cooper, J. A., Reid, G., Cross, S. and Moore, C., ‘Integrated Multi-Trophic Aquaculture: What It Is, and Why You Should Care… and Don’t Confuse It with Polyculture’, North American Journal of Aquaculture, 70.2 (2008), pp. 139–158.
Morris, J. P., Backeljau, T. and Chapelle, G., ‘Shells from Aquaculture: A Valuable Biomaterial, Not a Nuisance Waste Product’, Reviews in Aquaculture, 11 (2018), pp. 42–57.
Troell, M., Joyce, A., Chopin, T., Neori, A., Buschmann, A. H. and Fang, J. G., ‘Ecological Engineering in Aquaculture—Potential for Integrated Multi-Trophic Aquaculture (IMTA) in Marine Offshore Systems’, Aquaculture, 297.1–4 (2009), pp. 1–9.
Waters, T., Jones, R., Alleway, H., Gentry, R. and Xu, A., Analysis of Farmed Seaweed Carbon Crediting and Novel Markets to Help Decarbonize Supply Chains (2023).