March 08, 2023

The acid test: taking carbon dioxide removal to the community

Learnings from a community feedback session on ocean alkalinity enhancement
St Ives Bay

It’s not every day that a local community gathers to explore ocean alkalinity enhancement (OAE) and what it would mean if a project came to a bay near them. That’s why I went to observe a community comment session in Cornwall, south-western UK last week organised by Planetary, a Canadian company hoping to trial its OAE method in St Ives Bay this summer and discussing carbon removal in the community

Over fifty local people came to hear Planetary’s vision, ask questions and provide feedback in what could be the start of ongoing engagement. I sat at the back, among the videographers and reporters, and put my social science hat on. The societal dimension of ocean-based carbon dioxide removal (CDR) is woefully under-studied and I wanted to understand which themes would emerge, how had the session been designed to solicit genuine public engagement, and how would Planetary integrate community input going forward. But first, as is always the case with CDR, I needed to grasp the science. 

The science 

Planetary aims to remove 1Gt of CO2 from the atmosphere by 2035. How? By adding alkalinity to oceans around the world, dispersed across multiple sites. The alkaline substance they work with is called magnesium hydroxide, which separates into magnesium and hydroxide ions upon reaching the water. The hydroxide molecules combine with gaseous CO2 in the ocean to form bicarbonate ions. As a result of this conversion, the amount of CO2 in the ocean decreases and an influx of atmospheric carbon fills the void. In addition to removing carbon from the air, Planetary says their approach can reduce the local impacts of ocean acidification which, like global warming, is a consequence of rising carbon dioxide levels in the atmosphere 

OAE trial
A group of scientists sailing off St Ives Bay to measure the effect of Planetary’s OAE intervention. The 5-day trial took place in September 2022. The smooth areas of water, where the wastewater enters the ocean through openings in the pipeline below, indicates to the scientists where best to take their samples.

How will their operation work in practice? In Cornwall, Planetary plans to partner with a wastewater treatment facility to diffuse alkalinity into St Ives Bay through pre-existing infrastructure. As Planetary’s Chief Ocean Scientist Dr Will Burton explained, “magnesium hydroxide is transported to the wastewater facility, mixed on-site and then dosed into the wastewater pipe, which runs along the seafloor for two kilometres.” The pipe, which is situated off Godrevy Beach below the sea surface, already delivers 300 litres per second of treated wastewater into the bay – Planetary would simply increase the alkalinity of that outflow.  

Planetary OAE diagram
Layout of Planetary’s monitoring program, the measurements made at each location, and the resulting parameters required for calculation of net CDR. Source: Measurement, Reporting, and Verification (MRV) Protocol for OAE Carbon Removals by Planetary Technologies: V2.0

Seeking dialogue 

As part of its code of conduct, Planetary commits to “proactively seek[ing] out dialogue with stakeholders, including local communities at each project site” to address concerns and work towards shared success. The team has identified St Ives Bay, with its windy weather and shallow waters, as the “perfect testbed” for a 90–120-day trial that would remove a net total of 200-300 tonnes of CO2.  

The bay is among the UK’s most beautiful, beach-strewn spots, with a rich local history and present, a vibrant tourist industry and diverse wildlife. Preceding the trial, Planetary’s Vice President Peter Chargin organised two community engagement sessions with the aim of “starting a conversation… hearing from the public what concerns they have and if there are any serious stumbling blocks that would mean we shouldn’t continue in Cornwall.”   

Questions and concerns about carbon removal in the community

People from the local community wanted to know how their corner of Cornwall would benefit from the project, whether there was a risk of the removed carbon returning to the atmosphere, whether CDR carbon credits would enable the buying companies to continue polluting as usual (thereby making the climate crisis worse, not better), and how the project might negatively impact the environment. Some stated a hard redline when it came to the carbon market, calling on Planetary not to sell carbon credits for offsetting purposes to companies failing to reduce their own emissions.  

Dr Will Burt, Chief Ocean Scientist at Planetary, presents the science behind ocean alkalinity enhancement to an audience of interested members of the public who live near the proposed site of deployment.

Planetary addressed the technical questions in real-time, highlighting areas of high scientific consensus (for example, regarding the very long residence time of carbon removed through OEA) as well as flagging under-researched areas such as monitoring ocean-based CDR, ecosystem effects and the impact of global warming on the efficacy of OAE, which generally requires cool water.  

The social and ethical issues raised will require deep thought and further engagement – engagement that Planetary say they are wanting to do. Going forwards, they will collate the feedback, act on any commitments they made in the sessions and continue to liaise with interested local stakeholders. “We want to communicate with community members in whichever way they want to communicate with us,” Peter told me. “We’ll do our best to follow what they want.”  

After the session, I followed up with two climate activists in attendance to ask their preference for future community engagement sessions. Oliver Baines, a farmer and retired charity director who has lived in Cornwall for 40 years, suggests there be more time for discussion and comments as opposed to the question-and-answer model. “The question is how to effectively engage the public? It’s most important to listen to them.”  

Nichola Andersen, a habitat creation manager who moved to Cornwall 12 years ago, championed the participative democracy approach used by climate activists to reach group decisions. At future meetings, participants could split into groups to discuss parts of Planetary’s proposal and then share their takeaways in a whole-group discussion at the end, allowing for more active and inclusive public engagement.  

“Just and principled” : ensuring transparent carbon removal in the community 

At Carbon Gap, we advocate for a just and principled scale up of carbon dioxide removal. Public engagement is a key part of procedural justice, which refers to fairness of decision-making processes, especially at the local level where CDR projects will often take place. As CDR methods mature and developers identify potential locations for their activities, local communities come into the fray each with unique social contexts. In the absence of much needed government guidance, developers are designing their own public engagement programmes. If the CDR sector is to develop in a just way, it must combine the art of public engagement with the science of CDR, transparently sharing results of public feedback and co-creating best practices with communities. 

It’s tempting to try draw generalisable lessons from the St Ives Bay study, especially when so little guidance exists around CDR and public engagement. But, as CDR thought leader and social scientist Emily Cox notes, “what works for one CDR technique or one location/community might not work elsewhere, therefore the main goal of best practice is to start the listening process early to understand fully what is required in a particular context.” For Planetary, this process has begun. Now, it’s about following-through, sharing decision-making power with the local community, and co-creating spaces with the public for the public.  

By Kayla Cohen, Science and Policy Fellow