Introduction

In addition to rapid and substantial emission reductions at source, atmospheric carbon dioxide removal (CDR) is now essential to limit global temperature rise to 1.5 °C by 21001,2,3. CDR methods are needed to remove an estimated 1-2.9 Gt CO2/yr by 2030 (in addition to the 2.2 GtCO2/yr currently being removed as of 2023), with an additional 2.3 to 7.4 Gt of removal needed annually by 20504. “Novel” CDR methods will have an especially important role to play in achieving carbon removal on this scale. They are estimated to have a high potential for capturing and permanently storing atmospheric CO2, compared to more established, “conventional” methods (i.e. reforestation/afforestation, mangrove restoration). Novel methods include direct air carbon capture and storage (DACCS)5, bioenergy carbon capture and storage (BECCS)6, and ocean alkalinity enhancement (OAE)7. Most novel methods are currently under development, are not ready for deployment at the required scale, and have uncertainties around risks (including technological, social, and ethical) and governance.

Local stakeholders’ views on CDR could influence its deployment and upscaling in specific regions8,9. By stakeholders, we mean all parties with a potential interest in CDR activities occurring in, or affecting, a particular locality. This broad definition includes community organisations, local councils, businesses, government agencies, and members of the public. Place-based research, focusing on locations where CDR approaches are likely to be deployed, is necessary to understand local stakeholders’ views and priorities concerning these emerging technologies and their impacts on environmental and social drivers9. While there is a growing body of empirical research regarding public perceptions of CDR10,11,12,13, research that expressly considers local stakeholders’ perspectives is limited and largely explores northern-hemisphere perspectives14,15.

This paper presents findings from an Australian place-based study investigating local stakeholder perspectives of novel CDR, focusing on ocean alkalinity enhancement (OAE). OAE aims to enhance the ocean’s natural CO2 sequestration capacity by increasing the alkalinity of the ocean16,17. Methods include adding pulverised alkaline minerals to the ocean or spreading it on beaches, and the removal of acid via electrochemical reactions (see Fig. 1)18. OAE has high CO2 sequestration and storage potential but a low technological readiness level (TRL)19. Uncertainties remain as to the practical feasibility, durability of carbon storage7, and environmental risks associated with OAE20. Robust monitoring, reporting and verification (MRV) mechanisms are needed to assess the additionality and permanence of carbon removal21, and to underpin any market mechanisms incentivising OAE22. We focus on OAE in response to explicit calls for place-based social science research, which complements the prevailing emphasis in the literature on global governance9,23. Such research is urgently needed in Australia, particularly in the island state of Tasmania, where OAE field tests recently commenced (see Supplementary Note 1).

Fig. 1
figure 1

Ocean alkalinity enhancement methods: (1) spreading alkaline material on the beaches; (2) adding alkaline material to the ocean from vessels; and (3) removing acid via electrochemical method. Image created by Derek Fulton, June 2025, CSIRO.

Full size image

Existing research generally shows that stakeholders are unfamiliar with CDR11,24, and even less so with OAE. While techno-economic studies on OAE and other novel CDR approaches are growing, simply providing more scientific information is unlikely to be sufficient for their successful and socially beneficial deployment25,26. Open, inclusive conversations are needed, ones that not only promote facts but also consider how social logics and cultural values might be influenced by the deployment of OAE specifically, and novel CDR more broadly. This approach aligns with the concept of responsible innovation, which calls on scientists, researchers, and policymakers to prioritise societal values in innovation27,28,29. Considering the values and interests of stakeholders in the specific jurisdictions where these technologies may be deployed can help ensure that national and subnational CDR governance reflects the priorities of local communities30. This is particularly important in Australia, where notable differences exist across regions in terms of the natural environment, economies, communities, and legal systems. Place-based research is therefore essential to understand how “local communities perceive the prospect of CDR, and how CDR might relate to their own priorities on environmental change, economic development, and climate action”9. However, low levels of stakeholder awareness regarding OAE and other novel CDR approaches present a challenge for researchers, as stakeholders are unlikely to hold firm views regarding technologies that they are unfamiliar with.

Rather than seeking to elicit fixed opinions, we instead focus on the questions that Tasmanian stakeholders have concerning OAE. Our primary research objectives are to explore (1) the preliminary views of Tasmanian stakeholders concerning OAE, and (2) their knowledge priorities. We adopted an inductive approach to identifying these knowledge priorities, which encompasses both techno-scientific questions about OAE and the broader socio-political considerations, such as regulations, policies, and ethical implications. In this context, a knowledge priority refers to anything stakeholders feel they need to understand in order to form an informed opinion about the technologies. We adopt a bottom-up approach (Fig. 2), empowering individual stakeholders to ask questions rather than relying on expert-driven assumptions about knowledge deficits.

Fig. 2: A bottom-up approach for participant engagement.
figure 2

It consists of three steps: (1) This step involves an introduction of OAE to stakeholders, using either a publicly available video (for non-scientific audience) or an infographic. (2) This step focuses on identifying stakeholders’ preliminary views on OAE. (3) This step identifies what stakeholders’ knowledge priorities on OAE are, in order to form an informed opinion about its deployment. We also show responsible innovation and deployment of OAE as an iterative process with a continuous feedback loop for reflection and improvement. Identifying stakeholders’ knowledge priorities, we believe, can be critical to responsible innovation and the deployment of OAE.

Full size image

Although such bottom-up approaches may be commonly discussed in broader social science scholarship, their use as a formal methodological framework is still emerging. Cox et al.31 recently introduced a “question-led innovation” approach to identify public research priorities for enhanced rock weathering in Malaysia. They suggest that stakeholder questions can be analysed to identify underlying values and priorities early in the development of these novel technologies, thereby shaping the direction of future research. We agree with this perspective but also view it as an iterative process with value that extends beyond shaping CDR research. Many of the questions raised by stakeholders pertain to issues outside the direct control of individual researchers, including broader climate change policy and land use/marine spatial planning. As such, adopting a questions-based approach could therefore offer a pathway for stakeholder concerns and priorities to inform governance and policy development, ultimately contributing to responsible OAE deployment.

From 22 interviews with 23 Tasmanian stakeholders, we identified knowledge that stakeholders value and believe is necessary to develop opinions on OAE deployment. Most stakeholders were grouped across five categories: environmental groups, commercial fishing industry, government agencies, tourism operators, and ocean researchers (including researchers from social sciences). A sixth, “other”, category encompasses two participants who did not align with the main groups, one from a community organisation and the other from a non-fishing industry.

We found that all participants held preliminary views about OAE; some considered it ‘promising’, others were unfamiliar with it, and some had sceptical views. Regardless of their initial stance, all expressed a need for more information to form an informed opinion about the technology. Specifically, they sought details on technological feasibility, environmental and community impacts, governance, and how OAE contributes to climate policy. This indicates that local stakeholders care about more than just how OAE affects their immediate area, and addressing their knowledge priorities is essential for the responsible deployment of marine-based CDR.

Categorising preliminary views on OAE

Given the novelty of OAE, we sought preliminary perspectives only and did not aim to ascertain if participants would “accept” any eventual deployment. Consistent with the broader CDR literature, most participants had limited or no prior knowledge of OAE. During the interviews, we introduced participants to three OAE proposals: (1) spreading olivine on the beaches; (2) adding lime to the ocean from vessels; and (3) electrochemical OAE where seawater is pumped and treated in an onshore facility (Fig. 1). We classified participants’ preliminary views of OAE into three categories: “promising”, “do not know”, and “unconvincing” (Fig. 3).

Fig. 3: Stakeholders’ views on OAE.
figure 3

The left column shows the stakeholder categories represented in this study, and the right column shows their views on OAE, i.e., promising, do not know, and unconvincing. The strands depict the proportion of interviews reflecting each view. The numbers in the parentheses depict the number of participants associated with the nodes.

Full size image

At least one participant in each stakeholder category held a “promising” view, indicating that OAE should be investigated further. For example, a researcher said that “…the ocean has a huge capacity to store CO2…that makes the ocean quite attractive…” [I 17]. An environmental group representative spoke about the need to combat climate change impacts by highlighting, “…we all know…warming of the planet…we have been accelerating it…I suspect that the benefit of removing CO2…is well worth it for many lifetimes” [I 18]. These examples highlight participants’ interest in the oceans’ CO2 storage potential and the urgent need for climate action.

All participants required more information about OAE, and 36% (N = 8) had difficulties forming strong views. For some participants, this was due to general unfamiliarity, with one stating “I would need to know more about them [OAE]…to make a really careful opinion” [I 19]. Others required more specific information. For example, a participant from the fisheries sector said, “…I don’t know the science to know exactly what that [potential risks and benefits] would be” [I 12]. Specific information needs are explored further below. However, these statements indicate that these knowledge priorities need to be addressed for stakeholders to develop firm positions on OAE.

While no participants steadfastly rejected OAE, three were sceptical about OAE/CDR as a concept (viewing it as “unconvincing”). One participant had reservations about manipulating the ocean: “my initial response would be I’d probably feel more comfortable if it was sequestered underground but [not] in the ocean. I think you have got more control” [I 5]. Two others questioned the need for CDR: “…I just do not see how it is going to actually help…it is another case of us messing with things.” [I 6] and “…why would we find ourselves having to contemplate it [OAE] to start with…” [I 15]. These statements reflect broader concerns about intervening in the natural environment, even for the purpose of addressing climate change.

Developing informed opinions on OAE

All participants indicated that they needed more information regarding OAE to develop an informed opinion. We categorised these knowledge priorities into four themes: (1) physical impacts and operational footprint; (2) affected communities and industry; (3) actors and governance; and (4) potential to address climate change. The paragraphs below elaborate on these themes, considering examples of prominent sub-themes (Fig. 4). Stakeholders identified these themes with variable frequency, which reflects differences in their priorities (Fig. 5). Supplementary Note 2 provides illustrative quotes across the other sub-themes.

Fig. 4: Stakeholders’ four knowledge priorities to develop an informed opinion about OAE.
figure 4

Both the size and distance of the circles indicate the frequency: a larger circle positioned farther from its parent node represents a more prominent child node, suggesting it was discussed more frequently than nodes that are smaller and closer to their parent. For example, the sub-theme of environmental impacts was discussed the most in the physical impacts and operational footprint theme. The list of sub-themes is provided in Supplementary Note 2.

Full size image
Fig. 5: Distribution of the four knowledge priorities across the stakeholder categories.
figure 5

All themes were identified across all stakeholder categories. The bands represent the percentage of participants identifying the themes within each stakeholder category. The number of stakeholders interviewed within each category is shown below the category label by the letter “N”. For example, four participants belonging to the environmental groups were interviewed. Among them, all identified the physical impacts and operational footprint, deliverd climate goals, and affected communities & industry themes, while three identified the affected communities & industry themes.

Full size image

Physical impacts and operational footprint

This theme has environmental and technological dimensions. Participants required information on the potential ‘environmental impacts’ of OAE, including on marine ecosystems, aquatic life, and ocean tides and currents. One participant asked, “…how about all the little creatures that are in the water? How are they going to handle it…because of the concentrations of alkalinity” [I 6]. Participants discussed the need for further research and impact assessment before deploying OAE at large-scale. As a fisheries-sector participant said “…you want to be sure the flow-on effects are not going to be damaging” [I 12]. A government official similarly stated “…we would want really good evidence around what are its environmental impacts” [I 1]. This participant further emphasised the importance of small-scale trials to unpack these knowledge priorities, “…understanding it [OAE] at a pilot scale initially, so that you understand its dispersal and its impact before any expansion of the activity…”

The technical dimensions discussed by participants encompassed CO2 emissions. A prominent concern was the ‘scale’ of OAE required to affect climate change. For one participant, this encompassed “…not only building it [OAE infrastructure] but as well putting it into perspective of how much CO2 can actually be captured” [I 13]. Questions of scale are also related to environmental impacts, with one participant noting “…there is the unknown side effects…on a scale of what we are doing…we do not really know how it will affect things” [I 15]. Another from the environment group category stated that “…the scale of the whole thing is just mind boggling, what would need to be done to have impact on the whole of our ocean…” [I 18].

Participants also queried how CO2 sequestration would be ‘verified’. One researcher explained, “…just looking at that system [OAE]…How do you actually understand the degree of captured carbon [dioxide] because it is so reliant on this complex interface with [the] air-ocean flux…” [I 7]. A fisheries-sector participant similarly said, “Given it is the ocean, the challenge I see with that is the measurement for the differential between the before and after is going to be really tough to achieve” [I 3]. A related concern was the energy required for various OAE proposals. Regarding placement of alkaline materials on the beach or in the water column, one participant explained, “…generating the alkaline materials…involve[s] energy. What is the energy consumption to do that, and how does that stack up against the net effect of CO2 extracted from the atmosphere” [I 15]. An environmental group representative questioned, “Can it [OAE] be done solely through … renewable energy” [I 14]?

Affected communities and industry

Participants questioned how OAE might impact communities and livelihoods. Amenity was a particular concern, including the visual impact of coastal infrastructure development. As a tourism operator explained, “…if you are putting it [an OAE facility] in a beautiful residential area or a…national park coastline…people might perceive [it] as quite a negative” [I 16]. Participants also queried how OAE might affect the intrinsic value that Tasmanians place on the ocean (‘cultural impacts’). One participant working in the renewable energy sector stated, “It is the values that people hold very dear to having a healthy and safe ocean…as soon as you start trying to add anything chemical…There is a bit [that] affects the whole of the ocean” [I 6].

Participants also considered the potential impact of OAE on fishing and aquaculture (‘primary production’), as many either fished for recreation or livelihood. One participant from the fishing industry questioned if OAE would restrict offshore fisheries access: “…a lot of the wild fishery sectors are…going further to get the tonnage they need to get, but if we are having increased areas of water locked up [due to OAE] …it puts the squeeze on everyone…” [I 9]. Another participant raised concerns about coastal industries: “…we also have oyster farmers in the area and abalone…I would say strong seafood industry here [Tasmania]. So, this would be…hard…if it would impact their fishing stock” [I 13].

Participants were keen on understanding how OAE, if conducted in/from Tasmania, would benefit local communities (‘community benefit’), including employment opportunities and local services. One participant expressed, “…the west coast of the state is very exposed to weather and very wild country…quite often employment opportunities are rare because you are in a remote area…what …can [OAE] bring to a community?” [I 9]. Regarding local services, one participant raised the possibility of generating funding (‘co-benefit’) “which council can use for community, or which could go into medical or hospital services…” [I 13]. A further query was the potential for OAE to lessen the impacts of climate change and ocean acidification on communities. In this regard, one participant noted that “…we have real concerns around ocean acidification, and what it might do to our rock lobster…also to species that are really important to our indigenous community…if it’s an activity that might help protect those [species], that is really significant.” [I 1].

Actors and governance

This theme captures queries about the role of different actors in deploying OAE, and the decision-making regarding such activities. The location of OAE was the most prominent query. Location overlaps with the subtheme of amenity, but with a greater emphasis on decision-making and planning. Regarding any onshore development, one participant considered whether OAE could be situated near existing power and water infrastructure [I 2]. Others raised the need for marine spatial planning to manage competing uses of the ocean, including offshore wind and commercial and recreational fishing, e.g. [I 20]. As one government-sector representative observed: “all along the coast of Australia, we see this increasing marine spatial squeeze, understanding how much space it takes up and do you need buffer zones around this? …that spatial question probably needs to be explored” [I 8].

A further query was who would be involved in managing and overseeing OAE activities (‘ownership and involvement’). As a researcher expressed, “…making sure that these things [OAE] are managed in some ways rather than it being…left up to the private enterprise totally to go ahead…I think there needs to be that public oversight of these industries…” [I 4]. Another participant similarly said, “I am worried about who owns the technology and the political economy side of that…I am worried about a lack of ability for public interest governance of that ultimate technology…” [I 7]. These examples underscore concerns regarding how OAE deployment is regulated, and highlight the need for local, state and Commonwealth governments to develop policy and oversight mechanisms in the public interest.

A further consideration was the role of science in informing policy and decision-making (‘science-based decision-making’). For example, a government-sector participant stated that “if we’re making decisions, it has to be based on good science. If we’re lacking science, we will generally tend to avoid making a decision until that science gap has been filled.” [I 1]. Another government participant similarly commented: “You need to trial and probably more than once as well and probably different areas to get… the data to support your decision-making.” [I 13]. A fisheries-sector participant shared these views, stating that: “it’s very difficult at a policy level, at a government level then to actually move forward until there’s really clear scientific, at least a large proportion, majority agreement” [I 3].

Potential to address climate change

Finally, participants reflected on the role of OAE in addressing climate change. Across all stakeholder categories, participants queried the overall goal of OAE, requiring clear justifications for its development and deployment. For example, a researcher explained that not everyone is familiar with the need for CDR, stating that policymakers and implementing organisations must clarify “Why is it [OAE] imperative? Why do we need to do this?” [I 4]. Another participant, similarly, stated “I am still not really sure what the [rationale] is…I guess it is just an understanding of exactly what is being promised through all this and what the goal is, from a really explicit perspective…I think [this] is what people will struggle with a bit” [I 6]. According to a tourism operator: “…if the sea dies, we all die. It is important to get [the] message across [that] what you want to do is the right thing to do” [I 22]. This implies that the justifications given for OAE development and deployment, and how OAE fits alongside other climate change policies will affect the views of stakeholders. This is a salient reminder to scientists and policy makers to ensure that policies not only contain sufficient technical detail but also resonate with stakeholders’ values.

A common question across the researcher, environmental group, and government official categories was the potential for OAE to detract from conventional mitigation efforts. Several participants questioned the potential effect of OAE research and deployment on individual behaviour, e.g.: “I have this concern that if we put forward these ideas and enact them, that it gives people a ‘get out of jail free card’ … I therefore don’t have to take personal responsibility for where I hold my super or the kind of car that I drive or whatever because we’ve got these other solutions” [I 8]. Others raised broader climate policy implications, e.g.: “Does it then excuse ongoing fossil fuel production or pollution? Do big corporations get behind it and then use it to pretend that they’re not causing any ongoing harm? Does it delay efforts to reduce greenhouse gas emissions because we use it [OAE] as an excuse to continue operating current practice without continuing to try and reduce emissions?” [I 19]. The risk of mitigation deterrence, whether perceived or actual, could therefore affect stakeholders’ views of OAE. Not only is it important for such risks to be addressed through effective governance, but such measures should also align with stakeholders’ expectations. Further place-based research is needed to explore what stakeholders believe is appropriate and necessary in this regard.

Relatedly, participants were interested in alternatives to OAE and/or “novel” CDR. Several participants questioned whether more could be done to mitigate GHG emissions at source (‘other options’), including reducing consumption [I 21], land-clearing and development [I 4]. However, others considered whether greater efforts at ecosystem restoration are possible, such as blue carbon and afforestation. For example: “I do feel really sad and defeated in that where you do have natural carbon capture solutions…I would love if we could fix the climate crisis that way” [I 19]. Another participant wanted to know if research had been conducted comparing the carbon sequestration benefits of restoration activities versus engineered approaches, like OAE [I 20]. By contrast, several participants recognised the limitations of restoration activities, including vulnerability to extreme weather events [I 14]. Nonetheless, the extent to which participants contemplated restoration activities not only suggests greater familiarity with these approaches, but potential value-based preferences for restoration over OAE/novel CDR.

Discussion

Stakeholder engagement is necessary to ensure the responsible development and deployment of CDR32,33. In this study, we focused on OAE and engaged with Tasmanian stakeholders to understand their initial perceptions of the technology, as well as their knowledge priorities to form an informed opinion about its potential deployment in/around the state. Here, knowledge priorities should not be confused with an information deficit. The latter reflects a top-down view, where experts define what the public supposedly lacks. In contrast, knowledge priorities represent a bottom-up perspective, which is what local stakeholders want to know about unfamiliar technologies.

Our bottom-up approach, centred on eliciting individual stakeholders’ initial perceptions and questions, allowed us to identify key knowledge priorities at an early stage of technological development, well before any state or national policy development. This approach challenges contemporary stakeholder engagement strategies that primarily rely on top-down, expert-driven model of consultations34,35. The identification of knowledge priorities across multiple scientific and policy domains additionally allowed us to reflect on the pathways for the responsible deployment of OAE, which minimises social risk and reflects the values and priorities of local communities. Our findings have at least three key takeaways that can contribute to advancing the responsible deployment of OAE specifically and novel CDR more generally.

First, stakeholders’ knowledge priorities should be identified and addressed before social acceptance consultations. While social acceptance will be essential for the successful deployment and upscaling of OAE and other novel CDR approaches36,37, building that acceptance will take time. Researchers, innovators, and policymakers should not expect stakeholders to accept or trust technologies with which they are largely unfamiliar. That is why we did not ask whether the stakeholders would accept OAE. Instead, we focused on understanding their initial impressions and knowledge priorities. We found that most participants have yet to form a definitive opinion about OAE. While only a minority of participants expressed “sceptical” views, this nevertheless emphasises the need for careful, tailored engagement, and the possibility that, despite best efforts, some stakeholders may ultimately form negative views of these technologies.

Empowering stakeholders to ask questions further revealed that their preliminary views on the overall promise and desirability of these technologies are highly contingent, shaped by a range of techno-scientific and policy-related factors. In summary, participant’s attitudes might best be described as curious but cautious. Understanding the specific issues that stakeholders are curious and cautious about is important to avoid any expert-led assumptions about public information deficit and to prevent engagement strategies that work at cross purposes. Rather than presuming what local stakeholders need to know about OAE or other novel CDR technologies to promote social acceptance, we advocate for an approach that first identifies, and then responds to, their information needs and priorities. We therefore argue that CDR researchers and policymakers must adopt a self-reflexive approach and focus on understanding local stakeholders’ knowledge priorities before initiating any consultations on the social acceptance of CDR.

Our bottom-up approach could form the basis of local engagement approaches for OAE and other novel CDR technologies. By enabling researchers, innovators, and policymakers to identify knowledge priorities in specific locations, this approach represents a critical first step towards addressing those priorities in a just and fair manner38,39. Crucially, this approach does not presume that stakeholder acceptance of CDR can be achieved merely by “education” (i.e. provision of techno-scientific information). Nor does it expect stakeholders to hold confident opinions regarding the outcomes of technologies with which they are unfamiliar, and which are currently at a low TRL. Instead, it invites scientists, innovators and policymakers at an early stage in the R&D process to consider issues that stakeholders see as interesting and important, with the potential to shape future research, policy and engagement40,41.

Second, it is easy to assume that local stakeholders will, first and foremost, be concerned about impacts of a new technology or industry on their local community and surrounding environment. There are multiple examples that reinforce such an assumption, e.g., coal seam gas development in Australia42,43. However, this assumption did not hold entirely true in our study. On the one hand, our data shows that local stakeholders are concerned about local OAE impacts, such as on coastal environments and fish stocks. On the other hand, many of the questions that stakeholders raised went beyond a “local” scope. Stakeholders raised technical questions that reflect current scientific research priorities and objectives, including questions about feasibility, permanence, and verification of CO2 sequestration. In the context of asking stakeholders about future deployment and upscaling of OAE in their jurisdiction, such questions about the effectiveness of OAE and novel CDR inevitably have a local dimension. However, questions about governance (e.g., ownership and oversight), and ethics (e.g., mitigation deterrence) had strong national and/or universal characteristics.

Most noticeably, many of the governance and policy questions raised by participants demand multi-scalar action across local, state, national and international levels. For example, questions about land use and marine spatial planning, oversight and public-good governance, and the overall goal of OAE relate to government and policymakers at multiple levels. This reflects similar calls for multiscale and polycentric approaches to governance in CDR literature44,45. Other knowledge priorities, such as mitigation deterrence and input energy sources cannot be addressed in isolation from broader climate change and energy policies46,47. Our research therefore emphasizes the strong social dimensions of CDR governance and policy. A key challenge for policymakers will be navigating the different perspectives of affected communities, industries and interest groups, versus broader public views48,49.

Finally, the knowledge priorities distilled from our interview data reflect four key principles for promoting responsible innovation and deployment of CDR: accountability, sustainability, transparency, and the inclusion of societal value and ethics (Fig. 6). The connection between stakeholders’ knowledge priorities and these principles, presented in Supplementary Note 3, lends broader significance of this ‘place-based’, while the former is context specific, the latter offers a framework that can be applied more universally.

Fig. 6: Responsible innovation and deployment of CDR.
figure 6

The two headed arrows show bilateral relationships, meaning all key areas have mutual connections, and they provide and receive feedback from each other. Local stakeholders’ knowledge priorities reflect four principles of accountability, sustainability, transparency, and the inclusion of societal values and ethics. To align CDR deployment along these principles, a responsible pathway can be to conduct scientific research with accessible science communication, develop practical guidelines, and multi-level stakeholder engagement. However, further research is needed to empirically establish these connections.

Full size image

The scientific knowledge priorities, such as those concerning ‘permanency’, ‘feasibility’, ‘energy sources’, ‘scale’, demand scientists’ accountability in meeting societal expectations, a key dimension of responsible innovation50. Hence, any scientific endeavours must adhere to responsible CDR practices51,52, by, for example, ensuring that research and development not only addresses the questions that scientists want to answer, but that program are designed also to explore questions that are of importance to local stakeholders. CDR deployment will have impacts on local community and the environment, which demands knowledge priorities regarding sustainable resource management and community well-being in relation to creating ‘co-benefits’, minimising impacts relating to the local environment and culture. Local stakeholder engagement coupled with scientific research and assessment can be a responsible pathway in this regard. However, it is unlikely that scientific research and communication alone will be sufficient to address all knowledge priorities concerning responsible CDR deployment53,54.

Addressing governance knowledge priorities, such as those concerning ‘ownership’, ‘approval process’, ‘oversight’, and ‘funding’, will need transparent policy dialogues. Multi-stakeholder engagement should embed normative recommendations55, such as identifying governance approaches that resonate with stakeholders’ values and ethics23. The inclusion of First Nations communities and organisations will also be critical to ensure that their knowledge is integrated into decision-making processes56,57. These recommendations will then need to be implemented through law, policy and/or industry norms/guidelines58 to promote responsible deployment of CDR. Indeed, clarifying climate goals and how CDR is positioned to achieving them need to be made explicit in policy and clearly communicating the same to stakeholders has been identified as critical for ethical CDR research59,60. Further, alongside R&D, developing practical guidelines to include the views of a wide range of local stakeholders will be essential to assess knowledge priorities and CDR deployment.

Methods

Participant recruitment

This study was influenced by responsible innovation theory, which recognises the need for innovation addressing societal needs29. Additionally, it identifies why including stakeholders’ views in innovation can minimise associated social and ethical risks61. For CDR methods like OAE that have low TRLs, understanding the views of stakeholders becomes even more critical for their responsible innovation and deployment because of their unfamiliarity and uncertainty53. Thus, we set out to explore stakeholders’ views on OAE to identify what stakeholders’ priorities could be in relation to the responsible deployment of CDR.

Our focus in this research is to generate insights on a place-based deployment of CDR at an industry scale. We selected the island state of Tasmania as our case study and engaged a wide range of stakeholders who may be affected or have an interest in OAE deployment.

For participant recruitment, we organised a stakeholder mapping workshop with oceanographers working in Tasmania, which helped us identify broad categories of stakeholders. Subsequently, a desktop study was conducted to identify potential participants with a connection, interest or regulatory authority in coastal and/or marine environments in Tasmania. Additional participants were identified through our professional networks. Often, invited participants would decline to participate due to their low level of awareness of the topic. Our attempts to use snowballing as a method to recruit participants had limited success, as many contacts suggested groups or organisations instead of individuals.

Once organisations or individuals had been identified, initial contact about the study was made by email or an introductory phone call and follow-up email. The invitation to participate included background information and context about the research project; details about ethics, consent and privacy procedures; and explanatory information about OAE including a link to a publicly accessible animation about OAE on YouTube. Ethics clearance for data collection was obtained prior to sending out participation invitations for the study.

A total of 100+ potential participants were identified; 63 were invited for participation, with 23 participants agreeing to take part in 22 interviews (one interview involved two participants). The final participants were grouped into five categories: environmental groups (4), commercial fishing industry (3), government agencies (4), tourism operators (3), ocean researchers (6), and other industries or community organisations (2).

Data collection

Data collection for this study ran between March and June 2024 through semi-structured interviews (details available in Supplementary Note 4). We piloted the interview questions with oceanographers and social scientists to evaluate their relevance, flow, and timing. Based on their feedback, we revised the questions before finalising them. The interviews commenced with questions about the participants’ background and current role, followed by questions about the ocean’s meaning/value to participants and their perception of climate change impacts affecting the marine environment. At this point in the interview, participants were provided with contextual information about CDR technologies and how they are now considered a crucial part of global efforts to meet the Paris Agreement climate targets and net-zero emission pledges of national governments. General perspectives and familiarity with CDR were then explored.

The interview subsequently narrowed in focus on OAE specifically. Participants were introduced to the concept of OAE in a variety of ways. OAE was introduced to participants using a YouTube video by the Ocean Carbon Dioxide Removal channel. The link to the YouTube video was sent to potential participants in the email invitations and included in the participatory information sheet. Follow-up emails were sent to participants a day or two before the scheduled interviews; this email also included the link to the video. During the interview, we provided a brief explanation of OAE, outlining three different methods: electrochemical OAE, the addition of alkaline materials to the open ocean, and the spreading of silicate minerals along the shoreline. This explanation was accompanied by an infographic produced by Ocean Visions that depicted the three methods. Presenting the infographic provided another opportunity to explain and visually depict OAE. This was an important inclusion for those participants who had not watched the provided video prior to the interview, and ensured participants had some knowledge of the basics of OAE before answering OAE-specific questions.

We employed a ‘saturation’ method to determine the study sample size62. We reached saturation after our 22nd interview, meaning no new information appeared to be emerging. All interviews were conducted online via MS Teams, with the researchers present through video and audio. Most interviewees also participated with video and audio, while a minority of 4 participants were present via audio only. The task of interviewing was shared by several members of the research team, with interviews conducted both in pairs and individually. Verbal consent to record the interviews was gained from participants and the audio recordings were professionally transcribed for data analysis. On average, the interviews were 60 minutes in duration.

Data analysis

We analysed the data in three stages (Supplementary Note 5 for the data analysis flow chart).

Stage 1—All interviews were professionally transcribed, de-identified and uploaded in NVivo 14.

Stage 2—We used NVivo 14 for coding, involving three researchers. One researcher performed the initial coding of all transcripts. Two additional researchers reviewed the codes and suggested changes. Involving multiple researchers helped harmonise the coding process and enhanced the rigour of the analysis63. This collaborative approach facilitated the identification and resolution of discrepancies, leading to the recoding and refinement of themes, a standard practice in qualitative data analysis64. In total, the coding process was repeated seven times by the research team.

To generate themes and sub-themes for reporting, the coding of transcripts occurred in two separate steps. In the first step, we coded participants’ views on OAE and identified three themes of “promising”, “do not know”, and “unconvincing” by combining similar meaning codes. In the second step, we analysed what stakeholders want to know to develop an informed opinion on place-based deployment of OAE, resulting in four themes of physical impact and operational footprint, affected communities and industry, actors and governance, and deliver climate goals, and identified 22 sub-themes across the four main themes.

Stage 3—We produced all the visualisation in R software65 because of its wide variety of functionalities. All the data codes were exported from NVivo in the Excel format, which were then uploaded to R. We wrote codes in R to produce our figures; the data and codes we used are publicly available on CSIRO’s Data Access Portal66. We documented the frequency of each theme identified by participants to produce visualisations. Details of the R packages used for visualisations are provided in Supplementary Note 6.

Ethical statement

All participants provided verbal consent to take part in the study.

Ethics approval for this research was granted by CSIRO’s Human Research Ethics Committee under ethics application ID 191/23.

Reporting summary

Further information on research design is available in the Nature Portfolio Reporting Summary linked to this article.