Review approach and scope

Climate and environmental issues constitute one of the most visible, politically salient, contested, and empirically developed domains of scientist advocacy. Accordingly, this review focuses on climate and environmental advocacy by scientists, rather than attempting to review all forms of science communication or advocacy. For concision, we hereafter use the term “climate advocacy” as an umbrella term to refer to both climate and environmental advocacy by scientists.

Consistent with best practices for narrative reviews, which are particularly well suited to synthesizing broad, complex, or contested bodies of literature while allowing for interpretation and critique [31], we structured the narrative review around two guiding questions that were informed by the expert assessment, experience, and domain expertise of the author team: (1) What are the motivators and barriers to scientist climate advocacy?; and (2) What are the consequences of scientists’ climate advocacy on (a) scientific credibility and public trust; (b) audience attitudes and behaviors; and (c) scientists themselves?

The review mainly draws on empirical studies published in peer-reviewed journals primarily over the past decade. In addition, we draw on conceptual and perspective articles from peer-reviewed journals that describe scientists’ climate advocacy and set out the varied arguments for and against it. The narrative review reflects the authors’ interdisciplinary background in scientist advocacy and public perceptions of advocacy, drawing from social and environmental psychology, communication science, and philosophy of science. We also conducted a targeted, non-systematic search using Google Scholar. This search prioritised articles addressing climate and environmental advocacy by scientists, combining terms referencing scientists (scientist, researcher, academic), climate or environmental issues (climate, environmental), and forms of advocacy or activism (advocacy, activism, march, demonstration, protest, civil disobedience, policy advocacy, policy advice). This approach helped identify both empirical and conceptual work examining the motivations, constraints, and consequences of scientist engagement in climate advocacy, capturing a wide range of disciplinary perspectives and methodological approaches. We note that this is not a systematic review assessing the strength of evidence, but a narrative review providing an integrative overview mapping the terrain.

Definitions and terminology

For clarity, we define scientists as individuals with recognised scientific training or expertise engaged in the production, interpretation, and application of scientific knowledge, including those based in universities, research institutes, government agencies, and private organisations. This definition includes both natural and social scientists who study the drivers, impacts, and/or solutions to climate change, as well as those scientists whose primary research is not climate-focussed but who nevertheless engage in climate advocacy [18]. We adopt this inclusive definition to reflect the empirical literature, which documents a diverse spectrum of scientists from varied disciplines engaged in climate advocacy [25,26].

This wide variety of scientists engaging in climate advocacy also reflects ongoing discussions in the scientist climate advocacy debate about the extent to which individuals can legitimately speak beyond their primary domain of expertise and whether they are engaging in “epistemic trespassing” (where scientists speak authoritatively on matters outside their area of expertise thus constituting an overreach or abuse of authority) [14,15,19,20,32,33]. Further, it reflects inconsistencies in how “scientists” are defined across studies in this review.

Where studies make distinctions between (a) domain experts, whose research directly concerns climate or environmental systems (e.g., climate scientists, ecologists, environmental social scientists), and (b) cross-domain experts, who engage in climate advocacy from adjacent or more general areas of expertise (e.g., economists, psychologists, or other scientists who primary research is not climate or environment focussed), we indicate this explicitly.

We note that there is a growing body of research on climate advocacy by health professionals (e.g., medical practitioners, nurses, public health experts) including their motivations, barriers, and public impact [34–36]. While these actors also contribute to public debates on climate change, their advocacy typically foregrounds health impacts and is shaped by professional norms of patient welfare, prevention, and risk communication. As such, their roles, motives, and expectations differ in important ways from those of scientists as defined here. Hence, we do not discuss this literature in this review.

Finally, while some studies prefer ‘academic’, ‘researcher’, or ‘scholar’ [33,37,38], we use ‘scientist’ as an umbrella term to maintain consistency and align with empirical research on the scope and nature of scientist climate advocacy [9,16,25,26,39,40]. For further engagement with ‘scholar-activism’ more broadly, see Bashiri et al.’s review [38].

Whether a scientist’s action is perceived as advocacy often depends as much on the audience as on the scientist’s intent [15], with audiences’ perceptions being shaped by the actor’s role, context, and content of the action [24]. Some actions (e.g., policy advocacy messages, protest participation) are unambiguously recognised as advocacy or activism, whereas others (e.g., framing of scientific uncertainties, emotional expression, epistemic trespassing) are more context-dependent, varying with different audiences, messenger identity, and norms within and beyond science [15,37,41–45]. For example, a scientist may consider their communication neutral, but the audience may perceive it as advocacy. Another example is that policy-advocacy might be seen as undesirable, unless the scientist is specifically asked to make recommendations about policy.

While we acknowledge that communicative acts may be perceived as advocacy depending on the messenger, audience, and context, for the purposes of this review we define advocacy as the “act of persuading or arguing in support of a specific cause, policy, idea, or set of values” [46]. This definition encompasses a variety of communicative acts, including policy advice, selective messaging, display of emotions, institutional engagement, and climate activism. We understand the latter as an active form of advocacy [47], involving “the use of direct and noticeable action to achieve a result, usually a political or social one” [48], such as marches and civil disobedience. Where the literature or participants explicitly refer to activism, we retain that terminology.

Motivations

Many motivations for climate advocacy are shared by scientists and non-scientists such as efficacy beliefs, moral emotions, social identification, and perceived climate urgency [25,26,60–64]. However, recent work highlights factors specific to scientists. These include perceptions of scientists’ roles and identities, encompassing societal expectations of what scientists should do and how scientists themselves define and perform their professional identities in relation to advocacy [9,16,25,26,37,40,56,65], a motivation to defend science from attack [63], and research area, with climate scientists engaging in more climate advocacy than non-climate scientists [39].

For some scientists, climate advocacy is not a departure from professional norms but a fulfillment of them: They view it as a responsibility, as a duty for scientists [9,16,24–26,40,66–69]. In-depth interviews with climate scientists found that some scientists perceive it as their moral duty and as an act of defending science’s credibility during times when misinformation flourishes [24]. This has been also observed in interviews with non-climate scientists [9,16]. Focus groups with junior climate scientists revealed that some are motivated to restore public trust in science and warn the public about the dangerous impacts of climate change via advocacy. Some felt it was powerful if scientists participate in public protests or advocate for specific climate policies [56].

This sense of duty constitutes a “moralised” scientist identity, where speaking out is seen as integral to being a responsible scientist, and is a central motivation for sustained advocacy [9,16,26,40,66]. This identity may be reinforced collectively. For example, participation in identity-aligned groups or events, such as Scientists for Extinction Rebellion, Scientist Rebellion, or Science Week activities (public events promoting science), can help scientists feel supported, legitimise their advocacy, and strengthen perceived personal relevance [9,58,70]. These environments can provide supportive settings where scientists may contribute in ways that feel congruent with their skills, values, and professional identity [9].

Ethnographic research with scientist-activist groups further illustrates how scientists enact this identity in practice [9]. Shared symbols, such as the lab coat, are used to embody this sense of responsibility, and to communicate that advocacy is consistent with scientific identity rather than in conflict with it [9]. Observing peers taking action and participating collectively can help scientists accept activism as a meaningful extension of science communication, easing first-step hesitations and fostering a sense of belonging and empowerment [9]. Collective activities, such as staffing public information stalls, allow scientists to contribute in ways aligned with their skills and values while fostering belonging and empowerment [9,70].

Barriers

Scientists face a range of barriers to climate advocacy. Some are common to public engagement more broadly, such as limited time, uncertainty about what to do, not knowing anyone who is already involved, lower levels of climate worry, and low efficacy beliefs, both regarding the form of engagement and one’s ability to engage to bring about positive change [25,26,56]. Other barriers, however, reflect concerns that are specific to scientific work and the professional norms, identity expectations, and reputational risks associated with being a scientist.

A first set of scientist-specific barriers concerns beliefs about the scientific role, identity, norms, and culture [12,14,71–74]. Some scientists view advocacy as conflicting with norms of objectivity [24,26]. Not identifying with activists, or seeing activist cultures as misaligned with scientific norms, can also reduce engagement [25,26]. For some scientists who do choose to engage in spite of tensions, it takes work to reconcile being a scientist with being an activist [9,16]. Scientists who believe that technological innovation will largely address climate change are less engaged [26,40,59], and this belief varies across disciplines, with applied scientists expressing higher techno-optimism and humanities scholars the lowest [59]. However, recent evidence suggests that techno-optimism is also a barrier for engagement in the general public [75].

A second set of barriers concerns expertise and competence. Scientists may feel they lack the knowledge, skills, seniority, or disciplinary background required for public-facing action, or be uncertain about how their expertise can be used effectively [9,24–26,56]. This may partly explain why older and more senior scientists are more likely to engage [25,26]. Fear of failure or of engaging inappropriately can make engagement difficult, in addition to concerns about job security, particularly for early-career researchers [56]. Some are also hesitant because they worry that their own carbon footprint undermines their legitimacy to speak publicly [25].

Scientists also anticipate potential professional, reputational, or personal consequences. Fears of being seen as a “bad” scientist, damaging credibility, or jeopardising career prospects can deter engagement [24,25,37,56]. The polarised debate around climate change, harassment of scientists, and the incivility and misinformation that often accompany public communication, further heighten these concerns, especially among early-career climate scientists [4,56]. Some also worry that advocacy may be interpreted as an inappropriate use of their authority as experts, inviting allegations of bias or compromising perceptions of scientific credibility [24,26,32].

Finally, structural and contextual factors further constrain participation. Limited opportunities, the absence of colleagues already involved, and competing professional demands can reduce the likelihood of engagement [25,26]. Symbolic and disciplinary conventions within scientist-led initiatives may also create additional barriers. For example, the use of lab coats or technically framed markers of expertise, while useful for some, can alienate researchers from social sciences or the humanities, who may feel that such spaces do not reflect their disciplinary identities or forms of expertise [9].

Broader contexts shaping motivations for scientist advocacy

Motivations for scientist advocacy do not arise in isolation. They are shaped by broader social, institutional, and political contexts that influence how scientists understand their responsibilities, how their actions may be interpreted, and what forms of engagement feel possible or appropriate.

One key influence is how scientists perform and communicate their expert identities in public. Ethnographic work shows that engaging in public-facing action can strain the alignment between expertise and identity performance [9]. Some scientists draw on symbolic markers of expertise (such as lab coats or scientific papers) during public action, to signal credibility and justify engagement. At the same time, these symbols may generate expectations that scientists should speak across domains or represent science as a unified voice. This pressure to perform universal expertise, despite disciplinary limits, echoes arguments in the philosophy of science about the tension between scientists’ responsibility to communicate the seriousness of climate change and epistemic humility (being open about the limits of one’s expertise) about the extent of their knowledge. These debates centre on whether scientists have a duty to warn beyond their area of expertise, and at what point doing so risks being perceived as overreaching, undermining credibility [32]. Conversely, others argue that legitimate engagement can be grounded in membership within a broader epistemic community, where responsibility is collective, and extends beyond one’s specific area of expertise [33]. These identity, cultural, and rhetorical dynamics shape whether scientists feel entitled, obligated, or reluctant to speak publicly [26,76].

A second key influence is the wider political environment. Advocacy takes place within contexts marked by rising politicisation of science, climate scepticism, misinformation, incivility, and, in several countries, increasing criminalisation of protest [9,24,56,57,66,77–79]. In some settings, publicly defending science has itself become a form of resistance [56], while in others escalating legal penalties for protest have intensified the professional and personal stakes [78–81]. Such conditions can heighten scientists’ sense of urgency and moral responsibility, motivating engagement [16,40]; yet they can also amplify professional risks, intensify concerns about neutrality, and make some forms of action less accessible [24,56]. The same political pressures that spur participation for some may inhibit it for others.

Indeed, we observe that the results of the reviewed literature vary by socio-political context. Nearly all of the above studies were conducted in a small set of countries, in particular the U.S., UK, Germany, and the Netherlands. These national contexts are characterized by moderate to high levels of climate concern and trust in scientists but also by varying degrees of climate denial, misinformation, politicisation of science, and increasing repression of protest [4,51,77,78,82–85], which participants identify as key factors shaping their engagement, both as motivations and as barriers [9,16,24–26,56,57,86,87]. In the U.S. in particular, polarization around climate change is especially sharp [57,87], and several cases have been documented in which scientists faced severe harassment and legal threats, highlighting the professional and personal risks associated with advocacy in such contexts [4]. Because research remains geographically concentrated, we cannot yet know how these patterns translate to other regions with different socio-political, economic, cultural, and environmental conditions, including areas experiencing more immediate climate impacts.

Together, these contextual forces shape the interpretive space in which scientists weigh whether, how, and to what extent to engage. They influence not only motivations, but also which forms of advocacy feel acceptable or strategically viable. These same forces also shape how advocacy is perceived once it occurs, by publics, peers, and institutions. We therefore now turn to the evidence on what happens when scientists engage in advocacy and how these actions are interpreted across different audiences.

Effects on perceptions amongst the public

Evidence on the impact of advocacy on public trust in science and scientists is varied. Policy advocacy can have positive, neutral, or negative effects on credibility and trust. These effects may be influenced by national context, political orientation, public support for the advocated policy, and individuals’ prior policy preferences [27,29,88–92]. For example, climate scientists advocating for strict CO₂ limits on coal-fired power plants had no effect on perceived credibility of the communicating scientist, whereas advocacy for building more nuclear power plants as a solution to climate change reduced credibility [89]. In the U.S., advocacy for non-controversial policies such as tax rebates for energy-efficient vehicles and solar panels can increase the perceived credibility of the communicating scientist [90]. In Switzerland, scientists’ collective advocacy for a climate referendum, which was accepted by a majority of the public, has been found to slightly increase trust in scientists, especially among left-leaning participants [30]. In the Netherlands, advocating for the greening of gardens has been found to increase credibility of the speaking scientist, compared with adopting a more neutral tone [93].

The signals scientists convey about their role, behaviour, and values through their communication further shapes how their advocacy is perceived by the public. First, role framing affects credibility. For example, providing policy advice as an honest broker (i.e., a scientist who clearly distinguishes between scientific and political claims) as opposed to an epistocrat (i.e., a scientist who blurs the distinction between scientific and political claims) has been found to increase participants’ trust in the cited scientist and scientific evidence, especially among those participants whose policy preferences were not in line with the advocated policy [91].

Second, attitudinal-behavioural consistency matters: scientists perceived to “practice what they preach” are deemed more credible and influential, e.g., when they adopt sustainability behaviours [94]. When climate researchers are perceived to have large carbon footprints, their advice to reduce energy use is judged as less sincere, with negative consequences for their credibility [92]. Conversely, researchers with lower carbon footprints are more likely to gain public support for the policies they advocate [95]. Interestingly, this relationship may not be linear. Although scientists who are seen to ‘practice what they preach’ are generally viewed as more credible and influential, those perceived as exceptionally sustainable may sometimes provoke ‘do-gooder derogation’: negative reactions toward individuals seen as morally superior or implicitly critical of others’ behaviour. As a result, exemplary scientists can be less influential than more moderately sustainable peers in some instances [94].

Third, message content, tone, values and political signals further shape perceptions. When scientists make environmental policy recommendations, some research finds no effect on credibility [88,96], while other studies report modest decreases [97]. Critically, these effects appear contingent on factors such as individuals’ prior support for the policy and perceived value alignment between the scientist and the audience [88,96,97], underscoring the importance of the political and social context for shaping responses. Relatedly, insights from the broader science communication literature point to similar trade-offs. For instance, a recent review shows how self-disclosure (i.e., sharing personal details) can increase warmth-related perceptions (e.g., benevolence) while potentially decreasing competence-related perceptions (e.g., expertise) [98]. The emotional tone, narrative style, and political framing of scientists’ messages also shape public perceptions. A U.S. experiment found that when a climate scientist incorporated affect or personal anecdotes into their otherwise factual and neutral messaging, it did not diminish their credibility [86]. However, message consistency appeared essential: the scientist’s credibility and the public’s climate engagement increased when personal storytelling was matched with an optimistic or pessimistic tone, whereas factual communication was more effective when delivered neutrally. Evidence from online communication (such as tweets on climate change) suggests that stronger expressions of political partisanship by scientists can reduce credibility and willingness of participants to engage with their content, particularly when the scientist’s political identity does not align with that of the audience [99].

Together, these findings suggest that public responses to scientist climate advocacy are influenced not only by the advocated policy or evidence but also by how scientists signal their expert identities, values, and alignment with the audience. These interact with the audience’s prior attitudes and the broader political and social context, creating a dynamic interplay between communicator, message, and receiver.

Building on these communication signals, more visible forms of activism, such as public marches and civil disobedience, introduce additional factors impacting the effects of scientist climate advocacy. Research on the worldwide ‘March for Science’ in 2017 found a politically polarising effect of the march on attitudes towards scientists in the U.S., even as attitudes towards scientific research itself remained unaffected [100]. Existing experimental research in the U.S. context, based on a representative sample, and a student sample respectively, suggests that while civil disobedience by climate and environmental scientists does not increase policy support, it also does not reduce perceived credibility of the scientist engaging in or endorsing protest [28,101], and of their field of study more broadly [28]. However, experimental evidence with a representative French sample suggests that when a climate scientist explicitly presents themselves as an activist scientist (vs. a fact-focused scientist), this disclosure significantly decreases the scientists’ perceived reliability, trust in the scientists’ statement, and participants’ openness to reducing their meat consumption – especially among individuals on the centre, right, and far right of the political spectrum [102]. In line with these findings, experimental evidence in the U.S. found that environmental scientists engaging in conventional activism (i.e., holding a protest sign), were seen as slightly less competent and more hypocritical than non-activist scientists [103]. Disruptive activism (civil disobedience) produced stronger negative effects on competence and perceived hypocrisy, and potential spill-over effects on trust in the scientist’s field [103].

Overall, public responses to scientist advocacy vary considerably and the effects of advocacy are shaped by context. Advocacy can enhance, diminish, or have no effect on perceived credibility or trust in science and scientists, depending on factors such as policy content, public support for the advocated policy, framing, political orientation, national context, communication style, how the scientist signals their expert status, behaviours and values, and the type of advocacy. Effects, where they exist, are typically small, suggesting that advocacy rarely produces large gains or losses in public trust. However, emerging studies on scientists’ activism suggest either no effects or decreases in public trust. This picture also emphasises the need for us to consider that there is no single public that scientists are drawn from, nor communicating to, but instead there is a multiplicity of publics that are responding to these actions [104]. Relatedly, credibility can be thought of not as a fixed property of scientists, but as actively constructed in relation to multiple audiences, varying across institutional settings and national scientific cultures [105]. More broadly, the absence of clear consensus on best practices in science communication [98] further complicates efforts to draw general conclusions about the effects of scientist climate advocacy, reinforcing the need for more systematic and context-sensitive research in this area.

Effects on perceptions amongst scientists

Within the scientific community, perceptions of climate advocacy are themselves contested, often reflecting tensions between scientists’ expert and civic identities [42,106]. Some scientists express concern that public advocacy risks compromising norms of impartiality and politicising research, while others argue that advocacy is essential to defend scientists’ credibility and science’s authority and reputation [8,12,13,15,19,20,42,50,107–109]. These disagreements reflect deeper tensions over the social contract between science and society, epistemological commitments, norms of neutrality, and which types of values, and indeed emotions, are considered acceptable in science communication (e.g., societal values over individual values) [18,24,32,110–113]. Interview studies suggest that scientists run the spectrum from being strongly opposed to advocacy, to cautiously supportive, to actively engaging themselves, with scientists varying in how they balance responsibilities to evidence with responsibilities to society [16,24,105]. Recent survey evidence adds a further layer of nuance: while scientists in general are divided about their own role in advocacy, many believe that climate and environmental scientists, in particular, should be more publicly engaged [25,27,114–116]. However, beyond these studies, much of the evidence comes from commentaries and qualitative research (primarily from Western contexts), highlighting the need for more empirical, especially experimental, research on how scientists themselves perceive advocacy and activism.

Effects on engaged scientists themselves

For scientists who engage in advocacy, the tensions between science and advocacy may constitute an ideological dilemma [16,117]. Survey and interview research shows that some resolve the apparent conflict between advocacy and science by reframing advocacy as an extension of scientific responsibility [16,26]. This position is often accompanied by a rejection of techno-solutionist approaches in favour of systemic change and collective action [26].

Ethnographic and interview findings also highlight the personal consequences of advocacy, particularly where it involves public collective action. These include identity transformation, emotional strain, and the strategic boundary-work involved in presenting activism as compatible with professional expectations, in order to maintain both scientific credibility and the perceived legitimacy of activism within the scientific role [9,16,58]. Through sustained action, scientists may move from self-definition as a “scientist” to a hybrid “scientist-activist” identity, blending professional expertise with moral and civic responsibility [9]. These shifts are often reinforced through public performances of their expert status to justify action and signal ethical commitment — for instance, through the symbolic use of lab coats or scientific papers during protest [9]. Scientists belonging to collectives such as Scientist Rebellion or Scientists for Extinction Rebellion, described renewed purpose, solidarity, and empowerment through collective action [9,16,58]. Many also developed new practical and interpersonal skills, such as public communication, media engagement, organising demonstrations, or coordinating group activities, which supported their continued participation [9]. These experiences underscore both the risks and the transformative potential of sustained engagement, showing how sustained activism can reshape self-concept and professional identity while negotiating the tensions between academic norms and social responsibility.

Challenges and future research

Given that advocacy and its stronger form activism are often conflated in the literature, more conceptual and empirical work is needed to clearly define scientist advocacy, its forms, and boundaries. A particularly promising avenue lies in empirically operationalising insights from philosophy of science, especially those that explore the tensions between different values in scientific practice [14,88]. For instance, future research could examine the acceptability of different types of non-epistemic value judgments (such as widely shared social values), and how they may appear in scientists’ advocacy and communications, such as in expressing their emotions, selecting differing communication frames, or in the justifications for actions such as civil disobedience. Additionally, perceptions of what constitutes epistemic trespassing remain underdeveloped.

Future research should draw on the established insights into scientists’ motivations and barriers to further explore how they give rise to divergent communication strategies. It should also assess whether concerns about threats to credibility and the authority of science are empirically warranted, and how such risks can be mitigated in practice. One avenue, for example, is to examine how scientists navigate and alternate between identities such as “expert scientist,” “private citizen,” and “junior researcher,” and how these shape their advocacy communication. Another line of inquiry could investigate the potential benefits and trade-offs of strategically remaining silent. More empirical research is required to understand how the public interprets and evaluates scientists’ advocacy, including how people decide what “counts” as advocacy and which identity cues shape their judgments. This is particularly important given evidence that trust varies across scientific occupations and is strongly influenced by perceived morality and competence [118]. Qualitative insights can inform experimental work by identifying the actions, cues, and contextual assumptions that audiences use when evaluating scientists, allowing experimental research to move beyond binary distinctions between advocacy and non-advocacy toward more context-sensitive designs. For example, future research could explore how varying the type of scientist identity performed (e.g., generalist vs specialist, natural vs social) in advocacy shapes public trust and perceived legitimacy.

Further, what is less understood are the long-term impacts on scientists who engage in advocacy. Ethnographic work shows that such actions can prompt identity change and skill acquisition [9], but more work is needed. Do scientists in academia who then become advocates remain in academia, or do they transition into roles in policy, communication, or (full-time) activism? More broadly how does sustained advocacy reshape career paths and professional identities over time? Longitudinal research is also needed to determine whether advocacy enhances scientists’ influence on policy.

Beyond investigating the effects on the public and scientific peers, another important target audience is policymakers [119]. Much less is known about what policymakers expect from scientists in the context of climate change. For instance, it remains unclear whether this group is concerned that scientists are overstepping their boundaries, jeopardizing their credibility, or advancing a political agenda. What, if any, impact does scientist climate advocacy have on policymakers’ perceptions and actions? Moreover, interactions between policymakers and scientists appear to be relatively infrequent, with policymakers citing an ‘unmet desire for science’ [120]. This indicates the need for both more interactions between policymakers and scientists and empirical research on the impacts of such exchanges. A recent review on communicating with policymakers about climate, health, and their intersection highlights gaps in our understanding of the impacts of advocacy, noting that much of the empirical research focussed on knowledge translation instead of advocacy, did not generally examine actions such as protests, and that many of the communication recommendations made in the literature were not tested in controlled experiments [121]. Another relevant stakeholder group includes scientific organisations operating at the science-policy interface, such as the IPCC, as well as national institutes that employ researchers and provide political advice.

In addition to other stakeholder groups, it is critical to study scientists and their impacts in diverse national contexts. For example, recent U.S. policies under the Trump administration, including the firing of climate scientists and the removal of climate data from federal websites [122–124], provide a new context for investigation: how have these events affected scientists’ motivations and barriers to engaging in climate advocacy? How does this compare with other national contexts? Research remains dominated by high-income countries, but comparative insights from low- and middle-income countries are needed because of differences in socio-political and environmental contexts. Low-income countries in particular often experience the most severe climate change impacts [125,126], which are likely to shape how scientific advocacy is formed and its consequences.

Crucially, we need to disentangle effects across different domains: how actions influence perceptions of the individual scientist, the policy or issue at stake, entire scientific disciplines (e.g., how do perceptions of climate science as a discipline change if some climate scientists start joining protests?) and science as an institution. Evidence to date suggests that consequences may diverge across these domains, but systematic comparative work remains scarce.

A related methodological challenge concerns how both trust and advocacy are operationalised. Experimental studies vary widely in how advocacy is presented — from brief textual vignettes, to manipulated news articles, to real and fictional social media posts, to real and fictional protest images, and in what form of advocacy they depict (e.g., policy advocacy, protest, civil disobedience) [27,28,102,103,127]. Such heterogeneity complicates direct comparison and may partly contribute to the varied findings across contexts. Moreover, trust is often treated as a single measure rather than a multi-dimensional construct, with studies often conflating related concepts such as credibility and integrity. Some have argued for differentiating between trustworthiness beliefs — judgments of scientists’ ability, benevolence, integrity, and openness — and behavioural trust, or the willingness to make oneself vulnerable to scientific expertise (e.g., deferring to advice, supporting policy recommendations) [128]. Using validated multi-dimensional trust measures would add to our understanding of how advocacy affects different trust dimensions and highlight potential differences. For example, climate advocacy may negatively influence or have no influence on some trustworthiness dimensions (e.g., perceived objectivity) but positively influence other dimensions (e.g., perceived benevolence) [27]. Clarifying these conceptual and methodological foundations will be essential for identifying when and why climate advocacy enhances or undermines public trust in science and scientists.

Experimental studies on the effects of scientists’ engagement often rely on vignettes or fictional social media posts, which have strong limitations. Most importantly, they constrain how participants are exposed to scientists’ engagement to a short, decontextualized text summarising such engagement. This artificial exposure likely underestimates real-world effects, where individuals may encounter scientists’ engagement repeatedly and through diverse channels, such as news media, social media videos, or conversations with peers, which can amplify salience and emotional impact. They also flatten the multitude of potential effects that scientists’ engagement can generate, overlooking indirect, cumulative, and collective dynamics that unfold through public debate, media amplification, or institutional responses. Future research should draw on natural experiments and qualitative, in-depth work to better understand the effects of scientists’ engagement in climate advocacy and activism [129,130]. It could also explore the effects of recently proposed designs that integrate climate advocacy directly into field research [131].