Chile copper miner looks seaward for emissions mitigation

Researchers in Chile are exploring the potential of marine ecosystems for not only absorbing and sequestering carbon dioxide but also creating sustainable feedstock for carbon-neutral products for the local economy.

A pilot project – a Carbono Azul (Blue Carbon) initiative – is underway at a bay in Atacama region, involving the cultivation and study of a specific type of seaweed that grows quickly and which, compared with other variants and land-based vegetation, can soak up a lot more carbon emissions.

Carbono Azul, the World Bank says, is the term coined for carbon dioxide stored in the world’s coastal and marine ecosystems.

Launched in October 2023, the pilot project is being carried out by miner Anglo American – as part of a goal to become carbon neutral by 2040 – public-private development and innovation foundation Fundación Chile, aquaculture innovation center AquaPacífico and Universidad Andrés Bello.

Seaweed stores carbon, and later in the form of ocean sediment. It can also be used as a potential carbon-neutral feedstock for sustainable fuels production, via pyrolysis or other methods, and the likes of soil fertilization and remediation. 

Octavia Barra, environmental remediation and monitoring project professional at Fundación Chile, told BNamericas there were multiple potential uses.

Barra said: “There are different alternatives, and for all of them you need to do this analysis: first evaluate the potential market for the bio-product, and obviously associated costs, and considering that it’s under the Carbono Azul framework, the issue of emissions is also very important. 

“If you generate a fertilizer, for example, that can be used to substitute a chemical fertilizer, it needs to be in a place near to where this bio-product was generated or where the seaweed was cultivated [to reduce associated transport emissions].” 

Aiming for net-zero by 2050 via energy efficiency, power grid decarbonization, electrification of demand and sustainable fuel solutions, Chile has around 6,400km of coastline. Globally, seaweed forests absorb around 30% of annual carbon dioxide emissions.

Projects could eventually generate blue carbon credits, which can be used to offset carbon emissions from individuals or businesses. The World Bank is working in this area.

The Chilean project researchers are engaged in measuring carbon captured by the seaweed and sediment. One day, seaweed could potentially be rope-grown in managed areas of the coast for both absorption and for harvesting for usage in bio-products.

Researchers are working at a 1ha cultivated area at Bahía Inglesa. Seaweed grows rapidly, some types as much as 30cm a day. 

“We’re engaged in initial prospecting work, generating general baselines, and a methodology that may eventually be certified, which is important to consider since the generation of carbon credits requires a methodology validated by an international entity, such as Verra or Gold Standard,” said Barra.

This is trailblazing work, given no such certification methodology currently exists. 

Barra said: “Anglo’s Blue Carbon project emerged from their goal of achieving carbon neutrality by 2040 and there are emissions they will not be able to reduce. So, they’ll have to mitigate them and in this search for alternatives they looked toward the ocean and Chile’s potential in this sphere." 

“And they want to generate their own carbons credits to achieve this goal. They could buy any carbon credit but they want their own.”

Anglo is also working on a Carbono Azul project on the African coast. 

Other Carbono Azul projects are emerging in Chile, many concerned with repopulating, with seaweed, rocky areas of the shore in partnership with local artisanal fishermen. 

Today, Chilean seaweed is chiefly exported to Asia, for use as a foodstuff and as an input in the cosmetic and pharmaceutical industries. 

In Chile, wild seaweed is usually harvested by artisanal divers, raising concerns over sustainability and management of stocks.