The tropes of celebrity environmentalism

Celebrity advocacy for environmental causes has grown dramatically in recent decades. An examination of this expansion and the rise of causes such as climate change reveals the shifting politics and organization of advocacy. We address these changes to the construction and interpretation of celebrity advocacy and detail how they have produced a rich variety of environmental celebrity advocates. We also account for differences between legacy (e.g., radio, TV, newspapers) and online celebrities and their practices (e.g., hashtag publics,brandjacking,online communities).Environmental celebrity ad-vocates’ performances can be divided into nine tropes, each characterized in part by the particular varieties of environmentalism that they promote. We present the tropes and discuss their five cross-cutting themes. We conclude with a set of questions for future research on celebrity environmentalism.


INTRODUCTION
Over the past decade, celebrities' participation in environmental causes has expanded as climate change has gripped the globe and as the nature and forms of environmentalism change. Environmental and development activities are diversifying to include new actors and alliances, including nontraditional donor states, global philanthropists, consumers, and celebrities (1)(2)(3)(4)(5)(6)(7). These actors and alliances contribute to what Goodman et al. (8) term "spectacular environmentalisms"-"environmentally-focused media spaces that are differentially political, normative and moralized and that traverse our everyday public and private lifeworlds" (p. 677). As these spectacles increasingly shape environmental imaginaries and solutions to environmental problems, it is important that we understand the role that celebrities play in global environmental change.
Research on both environmental issues and celebrity is growing steadily but remains a nascent field, not easily parsed using systematic searches of scientific databases (Figure 1). In addition to the lack of volume, writings in this area can be surprisingly disjointed. Recent contributions reflect the lack of a single scholarly canon (9,10). As scholars in celebrity studies discover the environment and as environmental studies scholars begin to engage celebrity, much mutual learning is required.
To construct this review, we have relied primarily on our cumulative knowledge of the field more than systematic trawling of databases. This is because a typical search for key terms (e.g., "celebrity" and "environment") generates little material. However, while scholarship on celebrity environmentalism has not kept pace with the phenomenon itself, there are identifiable trends and arguments that merit treatment. Additionally, although many of these celebritized causes are global in scope and framed as primarily positive developments, they often exist within complex, fraught, and conflict-ridden terrain.
In this review, we argue that celebrities play an increasingly important role in shaping the way people understand and engage with the environment and environmentalism. Yet, we further contend that they often do so in ways that privilege forms of environmentalism and advocacy that typically-albeit inadvertently-reproduce structures of inequality. At the same time, the politics Trope: a recurrent theme or motif; in this context a particular sort of performance of celebrity activism with shared characteristics Legacy media: forms of media that pre-date social media such as newspapers, advertisements, television, and radio

Social media:
Internet-based media where the content is determined by users such as Instagram, Twitter, WhatsApp, and YouTube Publication trends of work on celebrity and the environment in Web of Science. We searched the Web of Science "Core Collection" yielding slightly more than 200 articles, of which 48 were genuine hits.
of celebrity advocacy can be unruly, particularly where environmental affairs are concerned. Their politics and consequences, we surmise, are not wholly predictable. Finally, on a practical note, the difficulty of writing about celebrity is that most writers like to think that their audience knows the person they are writing about. But the general condition of celebrity is that most people do not know about the vast majority of celebrities. There are simply too many of them. Although it is beyond the scope of this review to provide the details of each celebrity addressed, we offer references to guide further engagement.
The review proceeds as follows. First, we define what we mean by celebrity and explain how celebrity advocacy generally is constructed. Then we present the nine tropes of celebrity environmentalism that we have identified, outlining how they privilege particular forms of environmentalism. Finally, we offer a set of questions for future research on celebrity environmentalism.

DEFINITIONS
Readers of this journal may be familiar with the meaning of environmentalism, but not with the different definitions of celebrity. The characterization of celebrity varies according to whether we consider its discursive qualities, its organization, its power, or the media through which it is communicated. Historically, definitions have been derived from the appearance of celebrity in what is now referred to as legacy media such as radio, television, film, and newspapers. Today, we must also include definitions based on celebrity in social media.
The discursive definition defines celebrity as determined by its content-by the substance or amount of media coverage. For example, for Turner (11), the moment when a public person becomes a celebrity is marked by the moment the media become interested in their private lives. This helps to explain the gulf that can appear between the amount of attention celebrities garner and the greatness of their achievements. Yet, others, such as Boykoff & Goodman (12), suggest that celebrities are those with an elevated voice in the media and the capacity to shape public opinion more than others in both qualitative and quantitative terms.
Celebrity is also a commodity. Organizational definitions account for celebrity as an economic opportunity that can be earned from managing, and selling, appearances, endorsement, and www.annualreviews.org • The Tropes of Celebrity Environmentalism 389 Celebrity environmentalist: an individual who enjoys public recognition, publicly supports environmental causes, and benefits from their sustained public appearances brand-building opportunities that fame affords. Celebrity is distinguished by the management of fame such that it earns revenue for people other than just themselves (13)(14)(15). Driessens (16) defines celebrity as a form of capital. Drawing on Bourdieu's field theory, he describes how celebrity capital is different from symbolic capital in that the latter is a form of recognition, whereas celebrity capital is instead a form of recognizability. Recognizability allows celebrities to move between different social fields. This form of capital is key to understanding how celebrity activism can have influence, because it helps to explain why visibility in one social field creates a form of capital that can be credibly used to exert influence in other social fields.
Unlike legacy media and its tendency toward institutionalized and hierarchical gatekeeping, the Internet affords a wider array of dispersed, demotic, accessible, and innovative ways to cultivate fame and influence via a repertoire of platforms and features (17)(18)(19). Social media has facilitated the development of new forms of celebrity such as the accidental celebrity (20,21) and aspirational celebrity. These are ordinary people whose everyday experiences can be portrayed and packaged into commodities to capture the attention of willing audiences, regardless of whether or not they have special expertise or status (22,23).
The two broad pathways to Internet celebrity include moving from television to social media and from the Internet to elsewhere (24)(25)(26)(27)(28)(29)(30). Some ordinary people unknowingly and unwillingly become eyewitness viral stars (17) or meme-based celebrities (31,32), which are forms of fame that can be parlayed into an extended social media career. In a further extension of their commodification, monetizing power, and celebrity image, Internet celebrities may also merge with social media influencers. The value of influencers is anchored on creating Internet-based content on which endorsements can be embedded and promoted to audiences (33)(34)(35). On image and vlog-based platforms such as Instagram and YouTube, Internet celebrities often rely on an updated model of parasocial relations (36), such as perceived interconnectedness, where impressions of intimacy between the celebrity and audience are communicated and mediated online through commercial, interactive, reciprocal, and disclosive strategies (37). The forms and possibilities of celebrity, and the definitions of "celebrity," should be contextualized and their fluidity across diverse media forms recognized.
Thus, this review takes a pragmatic approach to the definition of celebrity environmentalists (7,14). Celebrity environmentalists are individuals who enjoy public recognition, publicly support environmental causes, and benefit from their sustained public appearances in any form of media. These media are typically shared with stakeholders employed to manage the appearances of the celebrity and who use their fame to advocate, fundraise, lobby, and/or create awareness of environmental causes.

CELEBRITY ADVOCACY
Celebrity activism for environmental causes is similar to other forms of activism. Indeed, the way that celebrity environmentalism operates in different media contexts, and among different audiences, and for different organizations, runs seamlessly alongside support for other causes. The strategies celebrities use (such as promoting awareness and raising funds through consumerism, YouTube campaigns, letters to newspapers, and appearances at protests or before policy makers) can be applied to almost any cause. Although some celebrities will develop particular environmental brands or interests, many combine these with support for a variety of other causes. Similarly, the organizations they support can also work for environmental issues and more general forms of development and humanitarianism.
Celebrity activism is a publicly performed concern that seeks credibility (14). Social media provides a sophisticated apparatus that is now used to manage celebrity performances in ways 390 Abidin et al.
that extend beyond the limits posed by legacy media. This is important because celebrity environmentalism may be a sincere expression of concern and a desire to change, but it must also look convincing. Authenticity is critical to the success of celebrity environmentalists' agendas. The pursuit of credibly authentic performances for good causes, including environmentalism, has been led by diverse nongovernmental organizations (NGOs) (1,3,5). Multilateral organizations (e.g., UNICEF) have been at the forefront of celebrity-sponsored environmental agendas. As Brockington's history of celebrity advocacy reveals (14), the enrollment of celebrities in social (and environmental) movements began to proliferate in the 1980s, but was organized more thoroughly from the 2000s onward. During this period, organizations began to recruit professional full-time celebrity liaison officers whose task was to cultivate credibly authentic relationships between a celebrity and their cause. They did this by creating and managing suitable meetings, writing bespoke newsletters, sending thank you cards and birthday cards, and other demonstrations of NGO-linked care work. In London, celebrity liaison officers meet monthly in a forum keeping minutes of their interactions. NGOs then use their celebrity patrons as part of their appeal to corporate sponsors, touting access to celebrity supporters on their websites. Media foundations organize workshops to train charities how to successfully manage their celebrities. In the same time period, three of the four major talent agencies in Hollywood set up foundations to manage the charitable interests of their clients. Websites now track celebrities' charitable interests (e.g., https://www. looktothestars.org/; http://www.ecorazzi.com). Celebrity magazines will work with NGOs to get stories about celebrities they want to showcase and help to manage and package field trips so that they feature talent that they want to interview and photograph.
In legacy media, celebrity advocacy for good causes is a niche element of the management of appearances. Celebrity environmentalism is part of this trend and work for NGOs, advocacy, or charity is now a fully integrated part of celebrity job descriptions (38).
There are far more NGOs looking for celebrity support than there are celebrities to provide that support. And celebrities have numerous and lucrative tasks beyond advocacy for good causes. Agents commonly tell their clients to choose three good causes and then to cultivate relationships with them. By doing so, they can more easily refuse the hundreds of other requests that they receive. Competition for celebrity attention can be intense. Indeed, one of the more prominent environmental organizations, which has many chapters in different countries, has been known to compete with itself for support from the same celebrity. This has led agents to complain about the lack of organization in the celebrity charity industry, especially among the most powerful players. Yet the incentives for this competition in a market of scarcity are clear.
With respect to the Internet, however, the means by which appearance for causes is managed and cultivated can be different. For instance, celebrity advocacy can be organized around a few key microcelebrities, and social media allows for a broader level of grassroots participation. Three types of online practices should be considered to understand the mechanics behind the construction of online celebrity rallied around specific conversation threads, occasions, or online communities. First, the use of so-called hashtag publics (such as #AskChevron; 39) facilitates the formation of ad hoc groups of people and conversations, especially for political and social movements and activism (40)(41)(42)(43). Second, so-called brandjacking allows users to spoil an intended message from a host's or brand's original marketing campaign and usurp the opportunity to spread their own message instead (44)(45)(46)(47)(48)(49)(50). Greenpeace, for example, used a viral video depicting a Lego miniature of the Arctic being overcome by oil spills, at the peak of The Lego Movie's popularity in 2014, to pressure Lego to reconsider its collaboration with the oil company Shell (51). Finally, online communities are typically centered on specific pages, groups, or Internet personalities as nodes around which users share resources, promote awareness, brainstorm strategy, and organize events www.annualreviews.org • The Tropes of Celebrity Environmentalism 391 (52)(53)(54)(55)(56)(57)(58). A sample of such community networks includes an activist documentary of the loss of natural landscapes and heritage sites on Facebook (59), a lifestyle documentary about ocean and wildlife conservation on YouTube (60), an education documentary around zero waste practices on Instagram (61), and the coordinated organization of climate change marches and movements on TikTok (62). Collectively, online practices such as hashtag publics, brandjacking, and online communities facilitate the development of new forms of online celebrity.

TROPES OF CELEBRITY ENVIRONMENTALISM
The political and social meanings of celebrity environmentalism are not easily understood through a study of individual celebrities, but instead require an examination of the broader collection of activities in which they participate. Some scholars have analyzed the organizational and institutional work that construct celebrity and celebrity activism (13,14,63). Others explore archetypes of particular celebrity performances or engagements from which particular lessons can be learned (9,(64)(65)(66)(67)(68).
In what follows, we provide a heuristic framework that can be used to understand the range of performances and how they conform to particular tropes. These tropes become coherent not through individual acts of celebrity, but in their consistency in form and function. As David Spurr (69) points out, tropes can be identified through the mapping of discourse as well as through a genealogical investigation of their repetition and variation across time and space. Our use of tropes in celebrity environmentalism builds on Richey & Brockington's (70) analysis of tropes in celebrity humanitarianism, in which The authors of this paper reviewed recent contributions describing celebrity environmentalism from diverse academic literatures including politics, geography, media and communication studies, and development studies, alongside recent news reports and social media appearances featuring the newest celebrity environmentalism initiatives. From this diverse and broad scholarship written by ourselves and others, and drawing on the use of tropes by Richey & Brockington described above, we identified nine tropes of celebrity environmentalism ( Table 1). The tropes we identified emerged inductively, that is, from our reading of the material on them, and discussion by email, Skype, and in person. Each of our tropes of celebrity environmentalism characterize a familiar script in the ways that stories are told across diverse media platforms about our environment. Tropes are not mutually exclusive. It is possible, for example, for a "white savior" also to act as an "ambassador" and a "commercial TV product." The recognizability of celebrity can work in multiple fields of environmental advocacy. Tropes describe modalities of operation; they do not proscribe theaters of activity.
Substantively, our tropes demonstrate the interactive effects between individual actors, their constitutive apparatus, and their audience. As there is little research on audience responses, audience response in our tropes is primarily inferred (14; with the exceptions of 71, 72; for an overview of this literature see 73). The tropes are describing performative actions, not individuals alone, as celebrity is not understandable through an individual focus. Thus, in the following discussion, we describe the performative tropes of celebrity environmentalism, starting with a trope that goes beyond humans as environmental actors. 392 Abidin et al. Ordinary people Although much of celebrity is managed and produced, environmental celebrity is unruly. New people keep appearing in the public sphere propelled by the logic of their struggles in the first instance, and not any media or social media machine.

Celebrity Animals
The approach we have taken to celebrity, which emphasizes its construction and organization, may be unfamiliar to some readers. There is a popular misconception that fame reflects the inherent qualities of the star. Thus, we begin our tropes with celebrity animals because their work in environmental causes underlines most clearly how the operation of fame depends upon organizations, institutions, networks, and machinery behind the scenes. It cannot be determined by the talent, abilities, or volition of the animals concerned. Celebrity animals and objects can cause us to understand, act, or at least feel something about environmental problems. Goodman & Littler (74), echoing the writings on flagship species (75,76), argue that charismatic species can be particularly important in grounding environmental crises. However, they also note that the unequal distribution of these spotlights leads to significant inequality within the economy of media attention. What Nick Couldry (77) terms "the hidden injuries of media power" affects things, places, and animals as much as humans. Blewitt (78) has traced how animal celebrities such as Uggie (a dog), Jumbo (an elephant), Guy (a gorilla), and Dolly (a cloned sheep) can work as ciphers for telling us something about what he terms the "human socially constructed natural world." More recently, McCubbin (79) has critically explored what she calls the media-generated, celebrity-fueled "Cecil Moment," whereby the shooting death of Cecil the lion was redirected www.annualreviews.org • The Tropes of Celebrity Environmentalism 393 away from trophy hunting and onto lion conservation in ways that shifted it onto the "racialized, rural poor" of a genericized Global South. She argues that Cecil's celebrity popularized death and Cecil's own celebrity was taken by conservationists to replicate the existing tropes of conservation that dismissed anti-trophy hunting sentiment, but did not elevate African voices and viewpoints. Rather, those empowered by the Cecil Moment grasped and leveraged its momentum to elevate their voices and serve their agenda which targets the rural African poor as the source of lion decline and brings the momentum of the moment to bear on rural African livelihoods. (79, p. 202) The Cecil example illustrates well how celebrity brings spotlights to particular types of mediagenic environments and publicly popular causes. It may not necessarily raise new awareness and bring change, so much as to reinforce existing views and power relations.

Ambassadors
Ambassadors are the most prevalent forms of celebrity environmentalism. These are people who adopt environmental causes, having won their fame through other means. One exemplar is Harrison Ford, who has had a long relationship with Conservation International, a popular American-based environmental nonprofit organization. Perhaps most famously, Ford starred in the 2014 documentary series, Years of Living Dangerously, in which he is filmed on an insurgent mission to reduce carbon emissions through the denigration of Indonesian authorities and support of programs such as the Katingan REDD+ Project. Ford's work in Indonesia simplifies deforestation for popular audiences by creating simplistic categories of "good" and "bad" actors, at the same time as he essentializes corruption in postcolonial states (80).
Another environmental ambassador, Leonardo DiCaprio, has produced several environmentally themed films, including the popular Before the Flood (81). Unlike previous climate change interventions, this film showcases emotions and affect throughout the film-whether the smiles of Elon Musk or the sincerity of DiCaprio. It illustrates a distinct shift to a more affective mode of climate change intervention whereby the emotional registers of climate change define and carry the narrative arcs of these new forms of spectacular environmental media (8).
High profile engagements also bring celebrities as ambassadors together through alliances of foundations. For example, Lil Dicky's song and video "Earth," in which his "main priority is to get people to give a shit about saving the Earth," has now been dubbed "this generation's supergroup Band Aid" (82) and one of the "biggest all-star charity records since 'We Are The World' " (83). The video unites prominent contemporary musicians ( Justin Bieber, Ariana Grande, Ed Sheeran, and Charlie Puth) with actors like Leonardo DiCaprio, with all proceeds going to the Leonardo DiCaprio Foundation.
We can also include in this category the interventions of royalty who have shifted the global environmentalism landscape. Prince Charles of Wales and his sons have become spokespeople for climate change, organic food, and antipoaching. But they are treading a well-trodden track. Some of the earliest celebrity interventions for conservation came from the "penitent butchers," aristocratic hunters who lobbied for stronger conservation measures because they were concerned about the prospects of their trophy hunting (84,85). British royalty were also highly instrumental in popularizing particular ways of seeing Africa, and its wildlife, through such devices as the luxury safari (86). This has led to some notorious interventions. Prince Bernard of the Netherlands' secretive business connections in South Africa may have mobilized funding for both the WWF South Africa and bankrolling counterinsurgency forces who were active in the illegal ivory trade (87). 394 Abidin et al.
Interpretations of these interventions vary. In the case of "Earth," supporters insist that "[c]heckered context and all, a jokester using his newfound network to make an anthem about climate change certainly isn't the worst thing he could have done" (82). Yet, this misses the point. These engagements are interesting because of the sort of politics that they engender. The causes of the climate and environmental crisis are nowhere to be found in "Earth." Expressions of love and community for those experiencing ecological catastrophe at the hands of inequality, capitalism, and marginalization may seem weak and gestural. For example, Harrison Ford's traveling by private jet to meet former Indonesian President Yudhoyono illustrates broader trends in celebrity environmentalism. The private jet linking environmental celebrities with elite politicians suggests that ambassadors' celebrity environmentalism is emblematic, and constitutive, of post-democratic politics in action (14). It is a means by which citizens disengage from agonistic politics, at the same time as political elites perceive them to be engaged in politics.

White Saviors
One of the more surprising patterns in celebrity advocacy is the racial identity of the famous conservationists who lobby for Africa's wildlife-almost all of them are white. It is remarkable how a continent populated so overwhelmingly by people of color should produce so many icons who are not. This tendency is so notable that it was brilliantly satirized by the late Binyavanga Wainaina in his famous essay "How to Write About Africa." He observed that [a]fter celebrity activists and aid workers, conservationists are Africa's most important people. Do not offend them. You need them to invite you to their 30,000-acre game ranch or "conservation area," and this is the only way you will get to interview the celebrity activist. Often a book cover with a heroiclooking conservationist on it works magic for sales. Anybody white, tanned and wearing khaki who once had a pet antelope or a farm is a conservationist, one who is preserving Africa's rich heritage. When interviewing him or her, do not ask how much funding they have; do not ask how much money they make off their game. Never ask how much they pay their employees. (88) It was this curious pattern that drove Brockington's (89) early research into the topic. He concluded that the demand for white conservationists is driven by predominantly white audiences in Europe and America who want to see the cosy imagined racial politics of Africa being saved by Europeans. This is the narrative with which they are comfortable. That audience fuels the commodified celebrity conservationists' appearances in films, and as spokespeople and leaders of prominent wildlife charities.
Rather than present one example as a case, the point here is that there are many to choose from, whether these be Richard Leaky, Iain Douglas-Hamilton (and possibly his daughter Saba), Cynthia Moss, Daphne Sheldrick, Diane Fossey, Jane Goodall, Craig Packer, Laurence Van der Post, George and Joy Adamson, or Ian Player; the list goes on and on. That some of these people (the Adamsons) never originally sought fame for their work-rather, as Beinart and others point out (90,91), the audiences found them-simply underlines the point that the role and creation of this trope meet a public demand.
And yet lists such as these are founded on racialized inequalities. As Garland puts it,

org/2017/07/28/the-big-conservation-lie-overview-and-interview-with-the-authors/)
Western fascination with saving Africa has, Ogada argues, very little to do with Africa's need to be saved, or indeed Africa at all. Rather, "[it] is not really an obsession with Africa. It is obsession with self. Africa's people or wildlife are just the tools to satisfy this need" (https://blog. nationalgeographic.org/2017/07/28/the-big-conservation-lie-overview-and-interviewwith-the-authors/). The conservation industry (and even conservation territories) is, in this perspective, constructed in order to create space for white saviors to make their mediagenic interventions.

Indigenous Heroes and Heroines
White saviors have a counterpoint in the form of indigenous champions of environmental causes. White saviors invoke a paternalistic intervention to save the environment because locals, it is assumed, cannot. Indigenous spokespeople have the authenticity and accumulated wisdom that their audiences seek. In the 1930s, the Englishman Archibald Belaney, masquerading as a First Nations elder named Grey Owl, enthralled packed audiences in Canada and the United Kingdom with his lectures (and publishers with his sales). He offered insights in the mode of the noble savages in which his audiences (and he himself ) were keen to cast him (94). Others, like Wangari Mathai, who won a Nobel Peace Prize for her work promoting tree planting in Kenya, serve as a counterpoint to the predomination of whiteness that surrounds celebrity environmentalism in African contexts.
It is striking that this form of celebrity, like the white saviors, but unlike the gurus and commercial TV products, is not often consciously and deliberately sought by the people who hold this form of fame. We can see this in the rise to fame of Chico Mendes (95). Mendes was a leader of the rubber tappers in Brazil in the 1970s and 1980s, helping to form their first union. He became famous in the late 1980s when US environmental organizations worked with him to advocate for conservation in the Amazon. His fame was secondary and accidental to his politics. It also did not travel, in the sense that it offered him no protection in Brazil from the violent landowners who eventually assassinated him.
It is helpful to distinguish between the politics of indigenous heroes in their home territories and on broader stages. In the latter, they are performing a role demanded of them by global audiences. There is conceptual space in the mind of audiences in the Global North, and market demand, for environmental spokespeople who speak with the authenticity of coming from the land. This invokes Oscar Wilde's famous observation "Most people are other people. Their thoughts are someone else's opinions, their life a mimicry, their passions a quotation" (96, p. 23). Applied here it suggests that the performances of environmental heroes on the global stage quote and mimic the expectations of audiences. One must distinguish, however, between the global stage and the local politics where indigenous heroes fight their causes. Mendes sought no global audience for his work-that was created in part by the international lobby groups who realized they needed his voice. Similarly, Edward Loure's Goldman Prize is rooted in his activism in Maa-speaking communities in Tanzania (https://www.goldmanprize.org/recipient/edward-loure/). The conceptual space that exists in the Global North does not define the politics of actually existing activism elsewhere. 396 Abidin et al.

Gurus
Gurus draw on a long historical imaginary of environmental truth claims. Environmentalist spokespeople are sometimes called prophets. John Muir, with his long silver beard, is well known as the Wilderness Prophet. But the term is also applied to such figures as Henry Thoreau, Aldo Leopold, and George Perkins Marsh. Prophets invoke the image of people who know and hear truth and who speak it fearlessly. We prefer the term guru because it captures how these actors speak out in ways that gather a following. Given their influence, gurus are surprisingly rarely studied. For example, David Attenborough's work reaches hundreds of millions of people, but the lack of attention to it in academic writing is notable given that he is "such a fascinating figure whose work has had such a profound cultural impact, both in Britain and elsewhere" (68, p. 16). Gurus are known as wise, cerebral figures who are skilled in using media to advance their causes, doing so in a way that makes their own stances appear impeccable and as embodying a moral and spiritual authority.
We use "moral" and "spiritual" deliberately, following Huggan's work in Nature's Saviours (68). 1 Huggan used the terms to describe the work of David Suzuki, who uses scientific authority to advance a "morally responsible sacred ecology" (68, p. 143). Gurus are comfortable with mystical authority, even if they also wield scientific authority-and they merge the boundaries between the two. They provide moral guidance through complicated dilemmas that surround environmentalism and conservation.
Clearly, gurus can only exist in the presence of an audience. And the tastes and values of audiences matter a great deal in terms of how highly a guru is exalted. Stott makes this point in his review of Prince Charles's book Harmony (97,98). He observes that the book "may delight and stir those for whom the world has never been modern" (97, p. 764). But for others, Stott suggests, it will be just "sublime mysticism and nonsense" (97, p. 764). One person's guru is another's fool.
The ramblings of Prince Charles that so annoyed Stott also demonstrate that a guru's ability to provide leadership is also a fraught political project. Their guidance can conceal and obfuscate the messy politics involved. Indeed, as Prince Charles's failures demonstrate, their credibility may hinge on doing so effectively. Guidance is not just guidance as to what to do about particular problems. It is about how to make them go away-how to deal with their representation in the public domain so that the desired solution also becomes the obvious one.
For example, consider Liz Garland's (92) writings on the case of the chimpanzee that had killed the young child of laborers in the Gombe National Park where the chimpanzee lived. Problem animals that attack people are routinely killed. But in this instance the chimpanzee was Frodo, famous among primatologists as the dominant male of a long-studied group. The Tanzanian authorities, purportedly abetted by Jane Goodall's phoning the Tanzanian president, spared the animal.
As Garland observes, there has been no publicity about the case in the Western press because "who wants to write a story that will bring negative attention to Jane Goodall?" (92, p. 55). But it nevertheless highlights that "there is a human cost to Goodall's eco-humanitarian mission, a rough underbelly to its smooth, seemingly apolitical surface" (92, p. 55). As Garland outlines, [h]er life is a testament to the potential of compassion to span the cultural divides that separate us from animals, and by implication, from one another. But where does the boy Frodo killed fit into Goodall's vision of cross-cultural harmony? And how are we to think about the structural conditionsfor example, the role of African laborers in maintaining her famous research site, or the susceptibility of Tanzanian government officials to the pressures of international public opinion-that are associated with her vision? (92, p. 54) Gurus reflect the contradictory position that environmental issues occupy in the public domain. They are, in their substance and detail, intensely political. But many publics like to think of nature and the environment as a place without politics. Gurus serve those desires.

Commercial TV Products
An essential aspect of celebrity is that it is a commodity. Celebrity exists and proliferates because it makes money. The archetype of celebrity as a commercial product is the late Steve Irwin. It is instructive to quote at length from Huggan's exploration of Irwin's work to illustrate this: Irwin acknowledged and embraced his global celebrity status, understanding its commodity appeal and the opportunity it afforded to sell further commodities . . . . Irwin understood his own value, and the value of the products he sold, in the global marketplace. Equally, he understood the value of the primary medium-television-through which these products were introduced and circulated as part of a hypercommodified "TV nature": one which, especially . . . during the last two decades of the twentieth century, had been seeking increasingly to capitalise on the selling power of charismatic celebrity presenters like himself. (68, pp. 185-86) The scale of the Irwin enterprise was remarkable. It involves a series of "Steve Lives" clothing, toys, games, books, a rebranded and invented wildlife park, feature films, and collaborations with the global chain Toys R Us (99). The Irwin children were also prepared for such valuable lives with a series of products featuring his eldest daughter Bindi Irwin (such as Bendy Bindi dolls). His wife Terri Irwin has received awards for her business acumen in helping to forge these activities.
As Huggan quickly points out, the sort of television that Irwin flourished in was a very different genre from the blue-chip documentaries that Attenborough had forged. This underlines the commodity role of such presenters (99). In blue-chip documentaries the focus is on the nature, the wildlife, and its scenery (especially the more gory and spectacular aspects) (100,101). But in Irwin's genre, the focus is on the presenter and his or her antics. This is much cheaper to produce. Far more footage derives from pointing a camera at a person, rather than waiting long hours for the right scene and lighting to present itself to patient camera crews (102). As blue-chip documentaries became more expensive, requiring coalitions of companies to support, Irwin's entertainment was simply better business-cheaper to produce and more appealing to a larger and new audience (103).
Notwithstanding the change in format, Irwin's success as a commodity was built on the common currency on which the commodity of celebrity environmentalists has to be built: authentic connection with nature and wildlife. This he achieved by making sure that he (and they) was in danger during his encounters, as his death so tragically proved. Apparent authenticity buttressed, falsely, Grey Owl's appeal as an Ojibwa elder that underpinned the sales of his writings. When his English origins were posthumously discovered, he fell from grace. Marty Stouffer presented the well-known show Wild America for 14 years in the 1980s and 1990s but was forced out when it emerged that some of the filmed encounters were also staged (89).
However, the way in which authenticity is performed can vary enormously. It can entail beingor becoming-indigenous (as per Grey Owl) or particular varieties of white Australian masculinity (Irwin). Authenticity builds on connections with nature, but the indexical lexicon that denotes such connection is rich and diverse. Commodification does not lead to homogeneity.

Entrepreneurs
Today we also see the rise of billionaire celebrity humanitarians who, although famous for their entrepreneurial success, deepen their cultural imprint through a range of environmental work run through their nonprofit organizations and foundations. Perhaps most notably, the Gates 398 Abidin et al.
Foundation founded by Bill and Melinda Gates has helped to forge this trend with support of people such as Warren Buffett. Numerous ultrarich philanthropists such as Jeremy Grantham, among others, had similarly strong interests in combatting climate change.
Our archetype of the environmental entrepreneur is Richard Branson, whose contribution as a prophet of green capitalism was the subject of a careful study by Prudham in his article "Pimping Climate Change" (104). Branson belongs to a high-powered group of investors who are seeking ways to make money from the decarbonization of the economy. The technological and energy shifts required are bound to be profitable for a canny investor who can spot what products, patents, businesses, and value chains will be required in future green economies.
Critics point out that new technology will not change the tendency of capitalists to exploit nature (and people) (104). This is unlikely to halt the inherently anti-environmentalist tendencies of capital. Moreover, as Klein (105) has also observed, Branson's visible and vocal enthusiasm for investing in a green economy has not been as generous or as long-lived as first seemed. Yet, the amount of money Branson actually spent or invested is irrelevant. In Prudham's argument, Branson's work is most apparent in his performance of the green entrepreneur. Branson's promotion of his businesses thrives on flashy, media-hyped extravaganza, including dramatic entrances to venues, well-promoted publicity stunts, and diverse travel adventures. Yet his is a performance of an expected role: "[D]espite Branson's apparent singularity. . . he cites and performs an alreadyexisting, virulent, muscular neoliberal, masculinist subjectivity reworked to fit the green capitalist agenda" (104, p. 1607).
Celebrity entrepreneurs are known for "pimping" climate change. "Pimping" climate change means that some of the contradictions and insults of capitalism, to society and the environment, are concealed beneath the bravado and gloss of these displays. Whether or not these displays, posturing, and investment result in a greener economy, or just cheaper space travel, they clearly shape the sort of environmentalism that gains public traction. They legitimize particular ways of thinking about the environment, the economy, and solutions to the problems of both, as well as particular forms of masculinity and entrepreneurialism. Tropes of celebrity advocacy like this are both acceptable and reinforcing of what the boundaries of acceptability are.

Activist Intellectuals
Activist intellectuals range across several different types of categories, including scientists (106), authors, and journalists who have gained celebrity and notoriety as outspoken environmental activists, campaigners, and speakers. A particularly prominent form recently has been the celebrity climate scientist (74). Examples include Bill Nye "The Science Guy," Michael Mann, Katharine Hayhoe, and Kevin Anderson. Their claims to credibility and authority to speak about climate change and environmental distribution come from their professional recognition as practicing scientists who actually know something about the topic they are speaking about through their training, research, and publications in scientific journals. But they are mirrored by a darker group of so-called celebrity climate contrarians (107). They tend to work for conservative and antienvironmental think tanks (i.e., the Heritage Foundation and the Heartland Institute) and question the science of climate change as a part of their job description. Their credibility comes, oddly, from the media's desire for "balance" in their coverage of climate change, as such giving space to these individuals even without any scientific credentials related to the climate (108).
Our archetype intellectual activist is Naomi Klein, a best-selling author and media figure. Emotion and affect, in the context of motherhood for Klein, are developed and articulated here as a way to make climate change more salient, real, and existential than through the use of climate statistics and reports. This mode of climate change celebrity media in UTS and Klein's earnest and touching story of introducing her son to the world works to develop, highlight and, importantly, translate and transfer emotion and affect for children, future generations, and ecologies onto individuals and the public. In Klein's media interventions, there is a hope of action that has us working to ". . . stop being so impeccably calm and reasonable. We're going to have to find that part of ourselves that feels this threat in our hearts, as well as our heads" (110).
Klein's hope captures a key dilemma of radical, activist intellectuals-their work is channeled into commercially valuable products that can conclude the extent of political participation in their audience, much to the chagrin of the key protagonists. The celebrity mode has to continually battle against the forms of disengagement it promotes. As Brockington argued, "[t]heir audiences live vicariously the lives of the radicals, as they do with other celebrities. They can subscribe to their arguments, and support their work, simply by buying the book, watching the film, or reading the article" (89, p. 124). Hence, Klein, in public speaking engagements, will actively combat that trend by naming and endorsing local groups that audience members can join.

Ordinary People
Grassroots and more local climate activists have also risen to celebrity status in recent years, exemplifying on social media and in the streets the celebritized trope of ordinary people. Along with the likes of Swampy and Blue who fought road-building in the United Kingdom in the 1990s, the most prominent archetype of this celebrity environmentalist trope is the youth climate activist Greta Thunberg. Begun from her solo Skolstrejk för klimatet (School Strike for the Climate) in August 2018, held outside of the Swedish Parliament each Friday, Thunberg has inspired both real youth climate strikes across the globe and a series of global movements centered on #Fridays4Future on Twitter and the Global Climate Strike movement through its website and Twitter hashtag #ClimateStrike.
Thunberg rips through the normalized and often ingratiating charm offensive of the typical environmental celebrities comfortable with the trappings and networks of social, cultural, economic, and political power. Her performances culminated recently in her presentation at the UN Climate Summit: How dare you. I shouldn't be up here. I should be back in school on the other side of the ocean, yet you all come to us young people for hope. How dare you? . . . You have stolen my dreams and my childhood with your empty words. We will be watching you. (111) She has had a strong impact on youth and the climate movement, credited with reducing the eco-anxiety of school children who participated in the climate strikes by countering the feeling of powerlessness and vulnerability by the lack of action on climate change by nations, politicians, and policy (112). This is mirrored by a humorous spoof video detailing a hotline middle-aged, white men can call if they feel threatened by Thunberg and her impacts (113).
Thunberg's fame hinges upon her and her audiences' use of social media. 2 Social media platforms command their own platform norms, with a dominant majority of users exercising their discernment over the types of content that tend to garner more attention and register more engagement online via views, likes, comments, or shares. On the highly visual platform of Instagram, one of the dominant norms for maximizing engagement is to curate eye-catchy, 2 As of November 29, 2019, Thunberg has 3 million followers on Twitter and 2.7 million on Facebook.
interesting, and professionally photographed images, and environmental movements are quickly learning to adapt to such social media preferences to facilitate awareness. One way the ordinary people trope of environmental celebrity works can be seen in the example of artists Von Wong and Joshua Goh who partnered with social impact strategist Laura Francois to stage an exhibition at the Sustainable Singapore Gallery by producing an Instagramworthy or Instagrammable space entirely comprised of plastic waste. The installation was made from "18,000 plastic cups collected from local food centers across Singapore" (114) to create a claustrophobic cave-like experience by surrounding visitors with plastic waste art works, in a bid to cultivate "plastikophobia," or an "aversion to plastic" (115). This art experience was also supplemented with educational facts and statistics about plastic waste in the country, such as its annual production of 800 million kilograms of plastic waste (115). Despite the bleak message, the installation was also strategically lit with beautiful fairy lighting that was "Instagrammable" and that encouraged visitors to document and publicize their visit and experience on Instagram via the hashtag #plastikophobia (https://www.instagram.com/explore/tags/plastikophobia/). This initiative generated much free publicity for the installation and simultaneously promoted the art exhibit and the message to reduce the use of single-use plastics.
Alongside this hashtag campaign, several social media influencers (i.e., https://www. instagram.com/p/BvBf2H8HWMK/, https://www.instagram.com/p/Bu5_aAnHlzI/) were also roped into publishing dedicated Instagram images of themselves to promote the installation, make pledges to reduce their own plastic footprint, and educate followers about environmentalism. This coordinated wave of posts that flooded Instagram enabled the #plastikophobia hashtag stream to quickly accumulate momentum and trigger the Instagram algorithm to promote such posts on the "Discover" page for other users to happen upon the campaign. Taken together, the hashtag campaign and social media influencers' initiatives utilized attention and algorithmic strategies to expand the reach of this environmental campaign.
The populist rootedness of this genre can also be subverted for commercial gain-albeit also for environmental causes. Given the pervasiveness of Internet culture, some initiatives have harnessed the power of clickbait and celebrity to seed sentiments and spread awareness about environmentalism. One such example is an advertising campaign by Israel-based manufacturing company SodaStream, who collaborated with heiress and public personality Paris Hilton in April 2017 on the NanoDrop plastic bottled water campaign (116). The original minute-long video promoted an extremely miniature version of plastic bottled water known as NanoDrop, which was touted as "a cutting edge, state-of-the-art condensed form of sparkling water . . .
[an] ultimate one-drop solution, five thousand times more hydrating than normal water, [where] one drop of NanoDrop equals one glass of regular water" (116). In the days that followed, the video went viral and trended on social media, alongside flurried discussions on several online fora. After widespread interest in the campaign, a follow-up video revealed this to be a witty April Fools' joke: The video ends with Hilton employing her iconic "ditzy blonde" demeanor to remind viewers to reduce their plastic use "because Planet Earth is so cute" (117). This campaign, although sponsored by SodaStream to promote their wares, was lauded as a success (117) for innovatively drawing attention to pollution caused by plastic bottles and providing an alternative to reduce plastic consumption. Even though Paris Hilton and Greta Thunberg are far from ordinary, their social media work is performed as if they were, well, simply ordinary and enlightening a viral public about environmental issues.

DISCUSSION: THE WORK AND PERFORMANCE OF CELEBRITY ENVIRONMENTALISM
Across these nine tropes, five cross-cutting processes are enacted. First, celebrity environmentalism is embodied. Second, it performs a mediating role that constructs the nature of www.annualreviews.org • The Tropes of Celebrity Environmentalism 401 environmental protest and movements. Third, it frames and directs affective responses to environmental problems. Fourth, it legitimizes particular forms of environmental politics. Finally, celebrity environmentalism often obscures the socio-ecological relations on which it is based. We explore each of these processes below. First, across all tropes, environmental celebrities embody-make fleshy and livelyenvironmental politics. They are, at the very same time, commodities made corporeal. The biopolitical implications of celebrity environmentalism and its affective embodiment are manifold. As consumers are hailed by the ideology of celebrity environmentalism, the environment itself becomes reified in ways that further obscure the relationship between consumers and producers of the environment. Celebrities, in this sense, contribute to ways of seeing the environment that privilege the individual affective consumer choices over broader structural change.
Additionally, environmental celebrities and their media interventions-much like solar panels, electric cars, and carbon credits-circulate and create value in the economy of green political markets. They are the epitome of the "vital materialisms" (118) that embody economic, cultural, and celebrity value created through their political utterances, environmental campaign images, and global protest attendances. They also embody responses to environmental issues in the same way they make low-carbon lifestyles fashionable.
Second, environmental celebrities mediate among the audience, different publics and nature. They operate in the interstitial spaces between us and the environment, witnessing for us, educating us, telling us what to do and how to save the planet. They are our go-betweens amid dying glaciers, burning tropical forests, recalcitrant world leaders, and caring green capitalists, often literally speaking on their behalf. They are our ecological muses of the Anthropocene. The interventions of celebrity environmentalists are designed to gain and maintain our attention through diverse performances and forms of "enviro-tainment," campaign events and protest marches.
Yet, mediation is not simply a passive exercise in environmental celebrities passing on the "truth" about climate change, fracking, or polluted water. Rather, much like any other media form, environmental celebrities actively construct the representations, meanings, and values of those everyday ecologies and communities affected by, for example, drought, coral bleaching, or plastics in the oceans. But the resulting activism is not always environmentally friendly. For instance, in Iceland, residents have sought to overcome the "Justin Bieber Effect," which describes the rapid increase of tourists to the island's ecologically fragile locations. It was coined after the release of Bieber's 2015 music video, "I'll Show You" that depicted the Fjaðrárgljúfur Canyon and triggered massive overtourism to the site.
Perhaps this should not be surprising. Contemporary relationships to, through, and with environmental celebrities more often than not now include what Büscher calls "Nature 2.0": the digitization of ecologies and environmental politics that "create new virtual forms and manifestations of nature and its conservation that intersect with material natures in complex new ways" (119, p. 1). As Büscher observes, Nature 2.0 works to both "encourage and complicate the commodification of nature and its conservation" (119, p. 1). New media, he argues, has the potential further to commodify nature into spectacle by, for example, turning biodiversity, landscapes, and ecosystems into forms of capital and thus further deepen the processes of the monetary valuation of nature.
In this form, environmental celebrity begins to replicate the very foundations of consumer capitalism through campaigns for voluntary donations, conservation programs, and sustainable consumption. Indeed, green, sustainable, and "conscious" consumption figure large in many a celebrity environmentalist campaign: All we need is the right app to tell us which sustainable fish to buy, a barcode we can scan to find the most environmentally just household cleaner, or, at a larger scale, which hybrid/electric car to buy. 402 Abidin et al.
In this respect celebrity environmentalism contributes to the rearticulation of humanenvironment relationships that encourage individual consumer action over state-supported structural change. It reframes the environment as a commodity to be rescued through celebrified action. This is significant for how it, as Latour (120) might suggest, reassembles the social in ways that spectacularize and reify the environment through alienated consumer choices. Furthermore, by branding environmental issues with celebrity names and agendas, the causes themselves become commodified in ways that overshadow their structural roots.
Third, through this active mediation, environmental celebrities implicitly and explicitly frame how the public should think about, feel, and relate to the environment. Environmental celebrities function through visual registers and performances-a bearded and sunglassed DiCaprio atop a melting glacier, a hard-hatted Schwarzenegger surrounded by the flames of a burning forestas much or even more than they do the discursive. Given this emphasis on the visual and their contributing performances, environmental celebrities are not simply translating and transmitting facts, words, and rational knowledge about global environmental change. Rather, they foster emotional responses in the audience and wider public ecosystems. In this sense, environmental celebrities frame affect-their own and ours by intention-as much as they do cognition through performance, narrative, and storytelling of, for example, the impacts of climate change on small farming communities in the US Midwest to the forest dwellers in Indonesia. They have, as Doyle et al. (121) argue in the context of climate change celebrities, begun to usher us into a so-called post-data world of environmental politics. No longer do we have the likes of Al Gore showing us PowerPoint slides of temperature versus CO 2 data points plotted on graphs. Even his latest film, An Inconvenient Sequel, now features videos of floods, typhoons, and hurricanes (122). Instead, Harrison Ford rages at the President of Indonesia about deforestation, a jocular Elon Musk smiles to DiCaprio as he explains how green entrepreneurialism in the form of solar power and battery storage will solve the climate crisis, and Don Cheadle visibly sympathizes with a devout Christian scientist doggedly attempting to convince her church of the existence of climate change. Greta Thunberg is the most recent incarnation of the emotive environmental celebrity: Her pinched and furious face, her shouts of "how dare you!" at the UN, and her admissions of sadness and anger firmly situate her concerns about climate change within affective and performative registers. In this current post-data era of environmental affects, environmental celebrities work to give us visualized performances of emotion that attempt to frame our own affective responses to save the world.
Fourth, with environmental celebrities, affect and, indeed, mediation can only be formulated through the processes of relating and the formation of relationships, including the relationships between citizens and the political entities that are legitimized to act on their behalf. Rojek (123) critiques this as "celanthropy": "big citizens" in the form of caring celebrities work for stateless solutions. These solutions are frequently advanced in ways that leave celebrities unaccountable to the public.
Mediation, affect and, indeed, framing denote relationalities among environmental celebrity activists, media forms, technological platforms, and audiences. Relating to environmental celebrities is cognitive and affective, technological and "natural," material, discursive, and visual. Relating through and with celebrity environmentalisms is, very often, about the desire to put into affective, cognitive, and material practice the new ecological ontologies of a more-than-human world. This is often ironic, however, as argued above, as, by their very nature, environmental celebrities can also work to suggest and reinforce the very separation they can sometimes work to overcome. The discourses, visuals, and campaigns of environmental celebrities devoid of people and humans' ecological impacts do this separation work.
Finally, through the production of new social engagements, celebrity environmentalism obscures the socio-ecological relations upon which it exists. This occurs where engagements www.annualreviews.org • The Tropes of Celebrity Environmentalism 403 with environmentalism result in new forms of commodification, when they ignore the hypocrisy inherent in some forms of ambassadors' work, or the politics they encourage, or when they engage in forms of environmental endorsement that are imagined in the minds of audiences before they are performed. These socialities and consumer choices have dire consequences for ecological crisis and have, as Latour (124) illustrates, triggered the earth itself to fight back against its human and nonhuman inhabitants. To address this trend, Latour calls for the representation of environmental issues: If politics has been drained of its substance, it is because the inarticulate complaints of those at the bottom are represented at the top in a form so general and abstract that the two seem to be without common measure. No wonder that politics is accused of a deficit of representation. (124, p. 94)

CONCLUSION
This review of the literature on celebrity environmentalism reveals a diversity of tropes through which it is enacted and the varied nature of its mode and outcomes. Collectively, these tropes contribute to long-standing political and ecological inequalities. Additionally, the limitations of the tropes of celebrity environmentalism lay bare the more popularizing representations of our politics of climate, conservation, and nature. Thus, these interventions can draw attention to significant, but selective, environmental issues. Yet, we cannot dismiss all forms of celebrity advocacy as compromised in this way.
The form celebrity advocacy takes is not determined by the trope of which it is part (125), nor is the audience response. It is possible to portray celebrity advocacy for the environment as part of a larger systematic incorporation of environmentalism by Big Conservation, with all its inconsistencies and subservience to capitalist logics. But where does Lil Dicky or Greta Thunberg fit into that mix? This is not something that is produced by the system as it alone wills. With the advent of online activism, this diversity and rambunctiousness take on extra hues. Online practices are increasingly significant sources of celebrity as well as media through which authenticity is cultivated. Practices such as hashtag publics, brandjacking, and online communities facilitate these developments.
Our review of the literature reveals questions and themes to which celebrity-and environmental-studies-focused scholars may turn their attention. In particular, we need to ask the following: How do some environments and environmental concerns become celebrified and not others, and why? As environmental agendas are also social agendas, we must consider the sorts of societies and politics celebrified environmentalism produce. And through celebrified environmentalism, we must address the types of changes celebrified environmentalism leads to and the sorts of environments it saves. Finally, in the context of diversified media and celebrity outlets, it is critical to understand what sort of environmental concerns, collective action, individualization, and social change are foreclosed by these choices.

SUMMARY POINTS
1. Celebrity is more than just prominent public appearance. Celebrity can be defined according to the way it is produced, managed, organized, and sold; according to its discursive content; or according to the forms of capital it creates.
2. Celebrity advocacy is produced in different ways in social and legacy media. In the latter, it results from an organizational shift in the way that NGOs have tried to seek out 404 Abidin et al.
and work with celebrities. In the former, the organization and production of fame are decentralized with advocacy built around influencers, hashtags, and brandjacking.
3. Celebrity environmentalism can be categorized into different tropes that capture particular and typical displays of celebrity environmentalism. Tropes provide a framework for talking about issues that highlight common themes and absences. In celebrity environmentalism these are afforded through (a) celebrity animals, (b) ambassadors, (c) white saviors, (d) indigenous heroes and heroines, (e) gurus, ( f ) commercial TV products, (g) entrepreneurs, (h) activist intellectuals, and (i) ordinary people.
4. Some tropes of celebrity environmentalism are adept at promoting particular forms of environments and environmentalism and conceal others. These forms of environmentalism (especially white saviors and commercial TV products) are rarely progressive and can perpetuate existing forms and structures of inequality. They frame, structure, and cultivate particular forms of popular environmental expression that fit well with the mainstream.
5. But celebrity environmentalism is not only an instrument of the mainstream. Some tropes (activist intellectuals, ordinary people) are unruly and unpredictable and can result in forms of protest that are less easily contained and limited.
6. Celebrity environmentalism can offer new resources to environmental causes that are not contained within the normal apparatus and players. However, some tropes (ambassadors) can also be incorporated and produced by existing forms and modalities of mainstream environmentalism all too well.

FUTURE ISSUES
1. What are the shadows and gaps in celebrity environmentalism? What are the unmediagenic environmental causes that celebrity environmentalism fails to illuminate?
2. As social media come to surpass legacy media in many publics, how will the form and substance of celebrity environmentalism change?
3. How are practices of celebrity environmentalism evolving in other media forms and formats?
4. The history of celebrity advocacy for environmental causes and that for international development causes are different, as are the tropes that they demonstrate. What drives these differences in the production and consumption of different forms of celebrity advocacy?
5. How can the democratic, unorganized potential of social media produce new forms of celebrity advocacy for environmental causes?
6. What instances exist of celebrity advocacy for environmental causes that have successfully brought progressive change and environmental amelioration?

DISCLOSURE STATEMENT
The authors are not aware of any affiliations, memberships, funding, or financial holdings that might be perceived as affecting the objectivity of this review.