Understandings of acceptance.

The first key dimension of acceptance is how it is conceptualised and understood as a term. One of the most common understandings of acceptance in the reviewed papers was as passive resistance indicated by a lack of publicly visible resistance. For example, the absence of public protests was interpreted as an indication that a project was accepted “or at least quietly tolerated” [73] (p.6235) and when surveys found a willingness to sign petitions against a proposed CO₂ storage project this was seen as a sign that the community did not accept the deployment of CCUS [27]. Acceptance was sometimes understood as consensus amongst established groups, for example where the interests of relevant stakeholders within a particular policy framework had aligned and thereby eliminated any visible opposition [57].

This implicit assumption of acceptance is interesting. In several of the reviewed papers what is meant by “observed acceptance and resistance” [74] (p.403) is not clearly detailed. Whilst local, social, and public acceptance may be mentioned several times [e.g. 75], it is not always clear why a lack of public resistance is considered to indicate social acceptance. This lack of clarity might be due to the policy-focused context that these papers emerge from. Within the policy context of CCUS, and other renewable energy technologies, acceptance is often conceptualised as a top-down process whereby energy infrastructure projects are “gifted” to local communities who are expected to passively accept and tolerate them [76]. Seen from this perspective the purpose of community acceptability research is to devise engagement strategies and practices that can ensure passive community tolerance of the project.

Although most of the literature approached acceptance as a lack of resistance, there were a few studies that contested this approach. One study of a project in Otway, Australia [77] found that some local communities could not access proper information about the project and did not have the resources to negotiate and engage with the project partners. This resulted in passive acceptance from the community as they did not have the capabilities to make their voices heard. Consequently, even when the project started to disrupt their businesses and cause some personal injuries, it did not result in open protest despite increasing dissatisfaction with the project [77]. Similar issues were found in a piece of research that compared how two communities near Sacramento, California with different material and social resources reacted to a CCUS project [56]. They found that the community that was socially and economically disadvantaged had the same concerns about the potential risk of the projects as the more affluent community, but the disadvantaged did not expect to have their voices heard when addressing these issues due to a sense of disempowerment [56].

Some papers found it important to consider how to move beyond passive tolerance and acceptance of projects. One suggested approach was to focus on capacity building of the local communities so that they were able to fully access all relevant information about the project and so that they were supported in their efforts to influence how the project is carried out and negotiated [77]. Another example of how this could be done was the ZeroGen project where a partnership consultation process was established in the planning phase and legal and technical resources were provided to the involved indigenous communities to increase their capacity to influence the project. This consultative process consequently led to a sense of partnership between the indigenous communities and the project team. Although there could still be disagreements the consultation was conducted in an atmosphere of trust [78]. These findings resonate with other research that indicated that communities that feel empowered by their capacity to influence projects and mitigate any potential risks are more likely to accept pilot projects [29, 56, 79].

Two of the papers questioned whether community acceptance was a crucial factor in deciding project outcomes. They argued that whilst the abandoned Barendrecht project is often taken as a case study to illustrate the importance of gaining community acceptance, it was rather the conflicting views amongst key policy stakeholders at the national level combined with a lack of understanding of roles and responsibilities amongst market actors that resulted in the project being terminated [80, 81].

This current review found that there was scope to engage more critically with how acceptance is conceptualised and understood by the project partners. Looking at the wider policy discourse on climate mitigation and adaptation, the concept of communities as passive recipients of climate mitigation and adaptation initiatives goes against many United Nations (UN) agreements, ranging from the Aarhus Convention that guarantees the right to information, participation, and justice in relation to environmental decision making [82] to the more recent Paris Agreement that emphasises the importance of participatory approaches, local knowledge systems and the rights of communities and vulnerable groups [83].

This emphasis on community-based and participatory research approaches also ties in with findings from the wider literature on climate change mitigation and adaptation that has highlighted some of the limitations of top-down solutions [84, 85]. As climate change was initially mainly conceptualised to be a global problem much of the early approaches to tackling the issues relied on global models that could not take account of local complexities [86]. This resulted in projects that implemented solutions that were ill-suited for the particular social and cultural context [87, 88] and that produced mixed results with unexpected adverse political, social, and economic consequences [89]. As a way to try to overcome these issues it has been suggested that more participatory and community-based approaches have the potential to empower communities [90–93], widen participation [94, 95], linking across scales [85, 96], and better utilise local knowledge [85, 93, 97].

This approach does not mean that participatory methods are a panacea that can overcome all the complexities of climate mitigation and participation initiatives. There are still important questions that need to be examined about the efficiency, impact, and sustainability of participatory methods [98–100] and it is still necessary to acquire a better understanding of the interlinkages between community processes and climate change mitigation and adaptation initiatives [85, 101]. Nonetheless, a participatory process that seeks active community acceptance and support could be argued to be crucial to ensuring the sustainability of climate change mitigation and adaptation. Also, although many of these lessons emerge from within the literature on climate adaptation, there is still scope for engaging more with these findings when it comes to understanding the relationship between acceptance and climate change mitigation initiatives such as CCUS projects.

Another issue that could be considered more thoroughly is that whilst a lot of the focus on social acceptance and communities emerges from concerns about resistance to CCUS projects, resistance is not necessarily problematic in itself. Several scholars have suggested that disagreement has great value in environmental issues and should be welcomed and embraced as it promotes pluralism in opinions [102, 103]. Ho [104] suggested that for the disagreement to be fruitful there needs to be mutual respectful discussions amongst all actors, as found in [103].

Another strand of research that could be fruitful to engage with is the literature that examines how social acceptance is a complex and multilevel construct that is important for both societies and businesses. Social acceptance of an innovation is an amalgamation of three separate levels of acceptance including socio-political, market and community acceptance [105]. Socio-political acceptance refers to the acceptance or rejection of technologies and policies by social actors such as policy makers and the lay public [80]. On the other hand, market acceptance considers the interactions between consumers and technology investors both in a competitive and collaborative context [106]. The third level of social acceptance is community acceptance referring to a project’s acceptance from local stakeholders including residents and the local authorities [105]. These three levels of acceptance can be argued to interlink and influence the outcomes of the CCUS project [80, 106].

To conclude, although acceptance is mostly approached as a lack of resistance in the literature, this kind of approach has been contested by a minority of studies that emphasise the importance of community capacity building to enable a more active form of acceptance and the importance of critically examining in what circumstances community acceptance becomes important. This review suggests that learning from the wider research on participatory methods, resistance and disagreement, as well as approaches to socio-political and market acceptance will enable a more robust understanding of the issues around how acceptance is approached as one aspect of meaningful community engagement practices.

Acceptance and engagement practices.

In the literature, methods of engaging with communities and stakeholders were commonly understood to be crucial in relation to the implementation of CCUS technologies and issues with the engagement processes were often found to be at least one of the explanatory factors behind why projects might be abandoned [e.g. 27, 29, 57, 73, 75, 107]. However, some contestation about what the aim and purpose of the engagement practices should be was found in the literature.

The most common approach to engagement practices was that they should help facilitate and improve the likelihood of community acceptance of the CCUS technologies [e.g. 29, 108–110]. From this research perspective, one important element in shaping the engagement process was the timing of engagement. A lack of early engagement might be considered by some communities as an indication that their concerns were not being taken seriously, which might in turn increase resentment towards the project [29, 111]. As far as possible, communities should therefore be involved early in the process, allowing time for them to digest the information [58]. Preferably the community should be engaged before any final decisions are made in terms of whether to implement the project at all, although that can be practically difficult to achieve [58].

For a few papers, the purpose of engagement was not only important to facilitate acceptance but could also play a part in promoting wider social justice issues. In the literature, three interrelated notions of justice were found and used to enhance the community engagement project, namely: procedural, distributional, and epistemic justice.

Procedural justice refers to whether the decision-making process is fair, transparent, and participatory. This could refer to the timing of the community engagement as mentioned above and related to past experiences. For communities that had been through a consultation process for other industrial and environmental projects, there could be an expectation that the engagement process would be merely procedural [112]. This could then result in a negative circle where a perceived lack of procedural fairness resulted in reduced willingness to participate in community engagement initiatives [107].

Distributional justice relates to how fairly and equitable the benefits and risks of CCUS projects are distributed across different communities. In the literature, there were some cases where the issues of distributional fairness were found to have an impact on how communities perceived projects. This concern was tied in with spatial dimensions. For example in connection with a project in Queensland where the CO₂ would be used for enhanced water recovery, members of the communities raised concerns about how the unequal spatial distribution of risk in terms of CO₂ leakage and the benefits of improved water levels would benefit some whilst disadvantaging others [30]. Similar concerns were found in a study looking at community responses to new energy projects in Ontario, including a CCS project in Alberta. Here the rural Ontario communities considered that they had to shoulder most of the risks of new energy developments whilst urban centres would receive most of the benefits [107]. Concerns about project motives were also found to contribute to a sense of unfairness in how the benefits and risks were understood. For example, there could be scepticism about whether the project was about addressing CO₂ emissions or facilitating capital accumulation for project partners [107]. This focus on distributional justice informs the policy focus on ‘just transitions’ that seek to ensure that communities and workers are not left behind or disadvantaged in the transition away from carbon-intensive industries [113].

Epistemic justice goes beyond distributional and procedural concerns to consider how people may feel marginalised and excluded when it comes to shaping the types of questions that are being asked and accessing the knowledge that is being created in CCUS projects [114]. Community participants were sometimes found to express notions of epistemic injustice if the CCUS project was seen as being part of a bigger policy where it was assumed that widespread CCUS deployment would and should happen [114]. For example, in the Barendrecht project, questions about the necessity of CCUS and potential alternatives were deemed irrelevant and suppressed during the community engagement [115]. This led to increasing public resistance against the projects which made the project politically problematic and ended with the abandonment of the project [115].

Whilst these notions of procedural, distributional and epistemic justice highlight important factors that can shape community impacts and acceptance, few examples of how to overcome these issues were found. One approach to addressing them was by seeking to use particular forms of community engagements such as “deliberate engagement process” and “deliberative workshops” [116, 117]. Such approaches would focus on active listening, the co-creation of knowledge, and the inclusion of diverse views from communities and stakeholders with the hope that, by seeking to foster collaboration, power imbalances between the local community and project stakeholders might be addressed [116, 117].

Although using more collaborative engagement processes is promising in terms of addressing some issues of injustice, it is still unclear to what extent they would be able to deal with procedural, distributional, and epistemic justice concerns. In the wider literature on climate mitigation and adaptation initiatives, there has been criticism of the notion that project practices, no matter how well-intended and how much they seek to be participatory, can end up being symbolic, ignoring structural inequalities and the ways communities may be shaped and influenced by political, social, economic, and environmental factors beyond their control [85, 87, 118–120].

To sum up, although there was agreement in most papers that the practices of engaging communities could play a role in shaping acceptance, the scope and aim of community engagement practices differed in the literature. Whilst some only focused on the timings and content of the community engagement practices [e.g. 27, 121, 122] other papers conceptualised the scope in much wider justice terms [e.g. 30, 107, 113, 114]. It was however not always clear to what extent community engagement practices in themselves could address the range of issues and concerns that shaped community acceptance.

Acceptance and knowledge.

Another key dimension identified in this review was how the link between knowledge and acceptance was understood in the literature. One conceptualisation of this relationship was that community and stakeholder perception of CCUS projects was shaped by a lack of awareness about the CCUS technologies that would be implemented in the project. This could then in turn lead to attitudes being shaped by a range of beliefs about CCUS that did not correspond with experts’ views. From this perspective, the best way to facilitate acceptance was to identify what patterns of awareness and beliefs people had about CCUS projects [27] and to consider how best to inform people about the technology [115].

However, there were a few papers that examined how the involvement of communities in the CCUS process could be beneficial in terms of contributing to what was termed as the ‘social learning’ of CCUS projects. Projects are often framed as part of a technical process, where scientific methods are utilised to establish objective facts that are to be communicated to the public and other stakeholders. However, the social learning approaches tie in with findings from social science that have questioned many of these assumptions [123, 124]. CCUS projects, like other technological developments, are characterised by many uncertainties [58] and are “a process that is not just about learning technical facts, but also learning about other aspects of the technologies integration into society” [124] (p.6249).

A paper by [57] illustrates how a broader social framing of project scope could facilitate social learning. By examining three projects in the United States (US), United Kingdom (UK) and Japan they found that projects that moved beyond technological learning objectives also enabled lessons to be learnt regarding wider social factors as they relate to CCUS projects. For example, one paper found that the Yubari project in Japan had a technocratic focus as “the justification of the project, the overall goals and results and the project’s relationship with society have been presented almost exclusively on technical and economic grounds” [57] (p.299). This focus on establishing technical and scientific facts resulted in minimal community engagement with consequently little chance to learn about wider social aspects of CCUS technologies. In contrast, the FutureGen (US) and Longannet (UK) projects sought to look at broader social aspects such as acceptance, education and legal regulations. This allowed more comprehensive social learning lessons to be achieved, although there was still much scope for wider community engagement in these projects [57].

Similar issues can be found in the paper by [54] where they reflect on their own journey as dissemination experts in the CCUS field. They started with a narrow framing of the issues that resulted in a top-down approach that assumed that they as experts knew what the problem and its solutions were and that the “public” was nothing but a barrier lacking insight and understanding. Yet as they became more involved in projects, they realised that this approach did not “recognize all the complex socio-cultural aspects that support innovation and problem-solving at the social level” [54] (p.4839).

A few practical suggestions were identified for how to open up space for social learning that moves beyond an exclusive focus on technical expertise. One suggestion was to try to move towards approaches based on mutual learning patterns [54]. To exemplify the benefits of this approach the researchers engaged with school children aged 9–10 and illustrated how this engagement had helped the researchers clarify the concepts they used whilst illuminating the wider social context of CCUS [54]. Another suggested approach was to classify CCUS projects as “unstructured problems” [29] (p.6380). This approach would seek to open up for wider questions about whether CCUS is useful and how it compares to other technologies. It would also seek to create opportunities for more inclusive dialogue between stakeholders and communities with different beliefs and values [29].

Alongside these different understandings of knowledge, it is important to consider how and by whom knowledge is produced and used as well as how there is a relationship between power and knowledge [125–127]. In his writings, Foucault criticizes the paradigm that knowledge should only come from institutions-such as universities- with sciences holding the power of truth [128]. In an attempt to address that issue, scholars have looked at participatory action research (PAR) as a platform to overcome the domination of knowledge associated with conventional research methodologies [125]. PAR allows for a more democratic process of knowledge development through the voices and experiences of local people [129, 130].

Pluralism of opinions can also be argued to be essential for democratic processes, as, through the expression of diverse voices and social interactions, societal conflicts can become more apparent and accessible to everyone [131, 132]. Furthermore, communities are important social spaces to in themselves, as they can play an important role in peoples’ knowledge development through social learning. Learning is a social process that takes place inside a social system [133], thus it is important to look at the implications it has on knowledge development amongst the different actors involved in CCUS projects.

The role of knowledge in environmental governance has furthermore also been discussed and explored by several environmental scholars [134, 135]. There is increasing recognition of the importance of local communities and indigenous people and their associated knowledge systems to climate adaptation policy [119, 127, 136, 137]. Indeed, both scholars and the Intergovernmental Panel on Climate Change (IPCC) have established the importance of knowledge generated by diverse knowledge systems in addressing climate change [127, 136, 137]. Although the importance of indigenous people has been researched and acknowledged, the necessary policies and strategies are not in place to incorporate that knowledge in climate change policy development [127]. This was also evident in our review that the experiences and knowledge of more marginalised communities were not represented or recognised nor used to build up more diverse ways of knowing and understanding the implications of CCUS technologies.

Defining and representing communities.

This review identified a range of approaches to defining communities. Some studies approached communities in terms of geographical boundaries centred on geographical locations [27, 73, 77], whilst others based their definition of communities and stakeholders around social interests in the project [78, 80, 138]. Some used more ad hoc approaches such as equating the readership of the local newsletter with the community [121].

There were also several different ways to conceptualise who represented these communities. One common approach was to consider stakeholders associated with local government, Non-governmental organisations (NGOs), academia, industries, and expert communities as representatives of their respective communities [54, 80, 81]. Another approach referred to groups of farmers, local residents, and landholders as being representative of the local communities [117, 122]. Others saw media as simultaneously reflecting and influencing community attitudes, centring part of their analysis on media discourses to reflect community concerns [73, 75, 117].

Most studies provided no extensive description of how the communities had been defined nor why they had chosen particular ways of representing these communities. This produced analytical ambiguity. For example, in a study conducted in Priddis, Canada, participants were grouped as “1) the general population of the area and 2) those who had a particular stake in the development or played a clear role in the opposition of the project” [139] (p.190). It is not clear here whether a participant opposed to the project (Group 2) was also a member of the general population (Group 1) as all the interviewees were residents of the area too.

This issue of definition hints at the complexity involved in studying communities. Notions of communities as simple, natural, discreet and static parts of the social world have been criticised for being based on unstated assumptions rather than a critical examination of what communities are in all their complexity [140]. How communities are formed, contested, understood and experienced relates to a range of local and global social, economic, material, and political processes [141, 142]. Whilst communities are often studied and conceptualised as a single unit tied to place or interests, it has been highlighted that actors interrelate across networks that often transcend these imagined community boundaries [143]. Furthermore, overemphasis on communities of place and interest fails to attend to ways in which micro-level interactions shape and rework these communities [144]. This is challenging for CCUS projects as environmental issues tend to interlink and move across the scales of historically constituted imagined communities [85, 145, 146]. How communities are defined, understood, and approached therefore also has implications for how community impacts and acceptance is made sense of in the reviewed literature.

Locating communities.

Our review identified a specific issue related to how the link between CCUS processes and the location of the communities was conceptualised. CCUS technologies refer to clusters of interconnected industrial processes and developments that can take place across vast geographical regions, interconnecting with wider environmental, social, and economic processes. This review was also interested in what part of these industrial processes is focused upon when researchers locate and identify relevant communities to engage with. The review found that the majority of the research focuses on the connection between community acceptance and the storage of CO₂ whether that was in projects that focused exclusively on the storage stage or whether it was in connection with studies that also explored the carbon capture, transportation, and/or utilisation stage of CCUS. (See Fig 4 in the results section).

This focus on the storage aspect of CCUS was often justified by referring to how many of the most well-known and impactful examples of community resistance has happened around suggested storage sites [e.g. 74, 80, 81]. These approaches were linked to a goal-rational framework where communities are seen as risks and barriers that can disrupt CCUS projects at different stages [75]. Papers that moved beyond the storage perspective included studies by [55, 147, 148] who explored the capture, utilisation and transportation aspect of CCUS. As mentioned in the discussion on acceptance, this fails to acknowledge justice and human rights issues of climate change mitigation initiatives and the potential for community participation to enrich social learning and project outcomes [124].

Although the cases that have received most research attention have been storage projects abandoned due to visible public protest, this should not be assumed as an accurate reflection of all CCUS projects, nor does it mean that this pattern will replicate for all projects as some community responses will be contextual and/or determined by the conduct of the particular project. As CCUS covers a range of integrated and connected suites of processes, examining communities solely connected to one aspect of this technology (e.g., storage) may limit our understanding of underexplored but crucial aspects of community acceptance as it relates to any CCUS project.

As discussed, communities can be conceptualised in a range of different ways, and it can therefore make sense to define communities dependent on the particular research context and framework. Consequently, research studies should utilise concepts of what a community is as determined by the place and particularities of that project, rather than on how this has been done in other projects with different sets of characteristics. For some CCUS projects where the storage element is central to the project aims it might make sense to focus on local communities near storage sites. Although there are no comprehensive databases that encompass pilot and demonstration sites [16] commercially operating CCUS facilities have so far been limited to capture and storage [149]. However, many of the ongoing and upcoming demonstration and pilot projects involve the utilisation element and one database estimates that 139 ongoing or planned projects involve a utilisation stage whereas the same number for projects that focuses solely on the capture and storage part is estimated to be 192 [150]. Although capture and storage continue to be prevalent in CCUS projects there are also indications that the utilisation element could become more significant. It is therefore important to pay attention to how these evolving technologies might also change how relevant communities are conceptualised and located as well as how engagement practices are shaped.

Knowing communities.

Who has the knowledge to define, delineate and understand communities was another dimension that shaped the research literature. This dimension has wider procedural, distributional, and epistemic justice consequences as definitions of communities can have impacts on who is consulted in the process and how benefits and risks are distributed. In much of the research reviewed, it was the sole purview of the researcher to define, delineate and determine the project’s relevant communities, suggesting a view of communities as distinct, unchanging, and clearly visible entities [73].

There were however some other ways of understanding how to explore communities that move beyond the views of the researcher. For example, focus groups conducted at two potential CCUS project sites in England left it open for the participants to deliberate on how to define relevant communities that might be impacted by a potential CCUS project [108]. Within these discussions, complex understandings emerged of the relationship between specific parts of the CCUS technologies and who the relevant communities and stakeholders might be. So for example the participants considered that the local place-based community was important when it came to the capture of CO₂ whereas when it came to offshore storage the community were conceptualised at the national level [108].

A similar approach was found in a paper focusing on how CCUS project experts approached the issues around engaging with and acquiring a social license from relevant communities. Focus groups amongst experts uncovered the complexity involved in defining and locating the “right” kind of community to engage with. For example, the problematic nature of locating “local communities” when the storage site was located in far-away offshore storage sites was highlighted. Interestingly, a more utilitarian and goal-oriented approach was evident amongst the CCUS project experts in the study as they considered the ideal local community to be one that was sparsely populated as that would make community engagement more manageable [151].

Who gets to define and know the communities ties into concerns about epistemic justice, what knowledge-making role communities should have in CCUS projects, and how best to engage with communities. This question of who gets to define communities is interconnected with questions of definition and representation. As PAR aims to democratize research and give voice to the local people [152], it might be that PAR participants are the ones that define what community they are part of. Even if approaches draw on the knowledge of stakeholders and communities in defining relevant communities there are still questions about what communities and stakeholders’ knowledge is sought out. Given the highly context-dependent and ever-transforming nature of communities as they relate to CCUS projects we cannot recommend a single correct answer to these questions. There will be many unknowns and complexities regarding who the communities might comprise. We argue that it is important to acknowledge and examine this complexity more thoroughly to achieve a better understanding of the nuances of interrelated communities.

Delineating impactful factors.

A key dimension shaping how impacts were conceptualised in the papers reviewed concerned what kind of factors and dynamics might shape people’s perspectives. All papers recognised that social factors played a role in people’s understandings and perceptions of impacts. There were however some differences in the role these social factors were seen to play and how they related to other physical factors.

Some papers took the position the impacts, and in particular, the risks, of CCUS technology projects were material properties that can be accurately estimated through technical risk assessments [110] and delineated from social perceptions of risk [162]. From this perspective, social factors can shape how these risks are perceived and made sense of, but they do not relate to the “objective” realities of these risks.

Other approaches focus on the social construction of CCUS technologies and their impacts [29]. In these approaches, impacts are inherently tied to different social factors and practices such as culturally embedded narratives [117] identity, history, social trust and economic context [163]. It is therefore not possible to separate any objective material facts as these facts are inherently tied to social dynamics.

These contestations about how to understand risk relates to wider debates where some argue that understanding risk is mainly an “objective” exercise where it is possible to calculate the probability for an action to take place and estimate the uncertainties around the consequences of that action [164, 165]. Yet others argue that risks and benefits cannot be narrowed down to objectivist estimates that can then be communicated to the unknowing public. Instead, it is important to examine what factors, dynamics and contestations shape risk and benefit perceptions amongst different communities and stakeholders [166, 167].

Regardless of how social and physical factors were delineated, most papers sought to identify particular important factors that had shaped people’s perspectives on a particular CCUS project. These factors tended to relate to four key aspects of risk: 1) financial; 2) environmental; 3) health; and 4) socio-cultural. Often the perceived risk of CCUS projects stemmed from uncertainty regarding the technology used, lack of trust in the project owner, lack of technical knowledge, previous experiences with similar projects and technologies, and the lack of involvement in decision making [75, 77, 116, 151].

How these different factors ended up shaping risk and benefit perceptions seemed to depend on the specific project context. Across the reviewed literature it was common for certain issues (e.g., financial and environmental) to be perceived both as a risk and as a benefit by different actors. This distinction often depended on the role of the respondent. The environmental dimension of risks and benefits is a good example of this distinction. One of the environmental benefits associated with CCUS is as a potential means of climate change mitigation as suggested by some participants [55, 74, 77]. At the same time, the environmental dimension was perceived as a risk associated with groundwater and soil contamination, marine pollution, natural disasters, and impacts on biodiversity [74, 79, 109, 163, 168].

Another example of differing perceptions of risks and benefits is how financial aspects are often perceived as a risk to the implementation of large-scale CCUS projects by corporations and employees [57, 147, 162]. Conversely, the potential economic transformation such large scale projects can bring to an area might also be considered one of the main benefits amongst communities [108]. More specific factors might elicit different interpretations. In some cases, CCUS projects were seen as potentially damaging to local tourism and real estate values [169], whereas in other project site locations with different local and social characteristics participants believed that CCUS would attract tourists and financial benefits for the community [73].

The characteristics of CCUS technologies may also influence people’s perception of risk and benefits. As a high impact technology [170], characterised by spatially wide-reaching networks and potential social and environmental impacts across multiple scales, the risks and benefits profile presents some particular challenges as they can often be unequally distributed [171]. These concerns link with concerns regarding CCUS and distributional and procedural justice. Some communities might feel they are not being involved in the decision-making process and they are being exposed to most of the risks whilst others reap the benefits [30, 107, 112].

In summary, whilst our findings identified a range of different types of factors that shape perceptions about impacts, be they economic, environmental, social, or health-related, how these factors play out in other specific contexts cannot be predetermined.

Impacts and uncertainty.

How to deal with the uncertainties about the potential impacts, whether seen as benefits or risks, was another key dimension shaping research approaches. That different factors can be interpreted in multiple ways only covers part of the complexity involved in determining risks and benefits in CCUS projects. Examining the wider research on risk illustrates cultural structures, identities and lived experiences can influence risk perceptions [172, 173]. This tension again speaks to the difficulty of examining risk as an abstract concept that is shaped by different social factors and the notion of risk as a physical reality with material properties [165].

In CCUS projects, both risks and benefits are dynamic constructs that can change throughout a project [78, 109]. There are different risk and benefit associated dynamics for the various dimensions of CCUS, i.e., capture, transportation, utilisation and storage [23, 174–176]. Furthermore, it can be difficult to fully predict how the specific technologies interact with complex environmental processes. For example, the risk of CO₂ leakage [177], could have multiple implications for human health, biodiversity, and groundwater contamination [178, 179]. Whilst the focus might be on the immediate risk (leakage), the implications can be multiple, and their risk profile can be difficult to evaluate in isolation.

The way the papers we reviewed approached this complexity differed. Some took a more technocratic view considering that given the potential risks and benefits is such a complex phenomenon it would be better to leave it to the technical, scientific, and social experts to deal with [110, 180, 181]. From this perspective, it was recognised that communities’ views on the impacts of CCUS projects were shaped in interaction with complex social-cultural dynamics [75, 180]. However, these social-cultural dynamics were understood as an element that needed to be considered when designing engagement practices in ways that would avoid misunderstandings regarding the underlying risk factors [182]. A two-way communication approach with the communities was recommended, to build trust in the expert’s ability to manage the impacts of the project [180].

Other approaches put greater weight on the communities’ ability to make sense of and contribute to complex understandings of the potential impacts of CCUS projects. For example, one study found that lay people provided with some basic information about the technology can comprehend and address complex issues associated with the risks and benefits of CCUS projects [182]. In some studies, communities illustrated this complex understanding of the issue by recognising that there would always be risk involved with any kind of project [114, 162]. However, community recognition of the potential risks of projects did not necessarily result in a rejection of the project. Rather it raised further questioning about whether the project team recognised the limitations of their expert knowledge and had made adequate preparations to address any unexpected outcomes [58]. When experts and laypeople participated together in citizens’ panels it was found that the two groups’ risk perceptions converged after the panel meetings had taken place, illustrating how these meetings can also help develop the experts’ knowledge about the potential impacts of projects [162].

Challenging impacts.

Many papers recognised that CCUS projects were often contested and that this related to how the potential impacts of the project were perceived. Whilst there were some examples of collaboration between experts and local communities, local communities often contested the information provided by the CCUS project partners. The potential risks, dangers and benefits were often found to be the main points of disagreement amongst companies and local community members. However, within the literature, there were different understandings of why these conflicts emerged.

The most common approach was that these conflicts could be mitigated through communication and public engagement, raising the question of how best to communicate and engage with the community to alleviate these tensions. For example [183] reported that amongst five different projects they reviewed, the projects that involved early communication and outreach were the ones that experience the least resistance against them. Often that success was due to trust-building amongst companies and local communities, as the local public trusted that the project owners would take all the required risk and safety measures to ensure the smooth operation of the facility [115, 183]. On the other hand, companies often failed to establish any trust with the impacted communities, and what these companies reported as risk and safety measures were seen as inadequate by the public [30, 56, 112].

This emphasis on the importance of communicating and engaging constructively with communities when dealing with risk links to particular risk perspectives that situate risk in psychological characteristics. Within this tradition, risk perception is how we understand and acknowledge the risk. Risk perception has been studied both from a cognitive and an affective perspective [184–186], as well as a dual approach process where both cognitive and affective assessments are deliberated [187]. Cognitive risk perceptions refer to logical and analytical decision making, whereas an affective risk perception is associated with emotional and heuristic-based decisions [188]. In extension [171], describe technological risk perception as the process where a person takes into account the “physical signals and/or information about potential hazards and risks associated with a technology and the formation of a judgment about seriousness, likelihood, and acceptability of this technology.” (p.293). That judgment is a combination of knowledge, values and feelings towards the technological risk [171].

This emphasis on communication and engagement regarding project risk was however not uncontested. A number of papers highlighted how procedural and distributional justice issues can play a role in creating discontent about the potential impacts of CCUS projects [e.g. 77, 114, 189]. How impacts were distributed and perceived was related to the social capital of the communities together with their history of marginalisation and empowerment when similar projects had been proposed in their communities [56]. Furthermore, if communities considered that the procedures leading up to the project had been unjust, it could also influence how they perceived the potential risks and benefits of the projects [27]. Building on these arguments was the perspective that the power imbalance between local communities, companies, and the national government should be taken into account when analysing how and why conflicts emerged and how they impacted the outcome of CCUS projects [190]. How to address these issues then become a question of how best to promote procedural, distributional and epistemic justice rather than how to design best practice engagement strategies to communicate the particularities of the project.

To conclude, how impacts are perceived is often an area of conflict between the communities and the particular CCUS project. Although practices of community engagement and communication have been found to contribute to shaping understandings of impacts, to what extent they can be divorced from wider social justice issues remains contested.