Tipping Point Forewarnings in Climate Change Communication: Some Implications of an Emerging Trend

Abstract

Prominent British and American sources now seek to structure public understanding of climate change by issuing “tipping point” forewarnings of danger with increasing frequency. This emerging trend announces a shift in the way we are likely to perceive and respond to climate change dangers. This paper reviews key statements to suggest a significant dimension of this trend is its enrollment of epidemiological terminology to communicate urgent and uncertain threats. First, key events in the popular employment of epidemiological and public health models of explanation are reviewed. Second, the author discusses the climate change “debate” to illuminate the limitations involved in treating climate change as a public issue detached from other problems involving atmospheric science. Third, the author reconstructs the tipping point tendency in this context. The essay concludes that the use of this concept signals a broader trend toward epidemiological models of explanation likely to activate public health styles of intervention for addressing climate change impacts. Some implications are briefly discussed.

Keywords:

• Climate Change Communication
• Epidemiology
• Gladwell
• James Hansen
• News Media
• Ozone Depletion
• Tipping Point

EARTH AT THE TIPPING POINT

(Time Magazine, 3 April 2006)

The way we talk about climate change in the western world is shifting. This change is signaled most clearly by the sudden ubiquity of the notion of “tipping points,” and though its emergence is difficult to date with precision, key statements are now evident. James Hansen, a climate scientist and director of NASA's Goddard Institute for Space Studies, often speaks of “tipping points” to express the dangers of climate change. Initially using metaphors of “loaded dice,” “time bomb” and “slippery slope,” Hansen's shift to “tipping point” forewarnings received prominent coverage in early 2006. British public discourse reflects a similar shift. Once famous for his reticence in speaking of the environment, former Prime Minister Tony Blair now warns of “catastrophic tipping points.” In an open letter to heads of the G8, Blair wrote, “We have a window of only 10–15 years to take the steps we need to avoid crossing a catastrophic tipping point” (Balkenende & Blair, 2006). Blair's Environment Secretary, Margaret Beckett, underlined his emphasis on tipping points: “The thing that is perhaps not so familiar to members of the public … is the notion that we could come to a tipping point where change could be irreversible” (cited in Black, 2006, ¶ 8).

These warnings mark a novel shift in the way climate change danger is communicated, an emerging pattern not easily explained. Hansen and Blair did not originate this style of forewarning and its contemporary influence is not simply a result of their prominence. But these statements demand attention if only for historical precedent. In 1988, James Hansen and then Prime Minister Margaret Thatcher made dramatic public warnings regarding the fact and importance of global warming, which most research agrees is the year climate change becomes a public issue. But what does it mean to reframe forewarnings of crisis in terms of crossing tipping points? How does this concept alter the way we perceive or respond to climate change?

It is important to avoid overstating the novelty of this “tipping point” tendency. The concept is not unique to discussions of climate change, it is not inconsistent with scientific ways of understanding how components of our climate system change, and it enrolls a way of seeing the world that is quite powerful, both imaginatively and institutionally. This last point suggests the main claim of this paper. Popular employments of “tipping points” advance an epidemiological or viral way of seeing the world. Epidemic models of explanation attach not simply to obvious examples—fears of Avian flu, SARS, West Nile virus, and bio-terrorist attack—but have proliferated widely as a sense-making device for events characterized by complexity, urgency and uncertainty. Computer failures, terrorist threats, information flows, marketing successes, financial crisis, violent crime, American obesity, female anorexia, all these social phenomena and more are now explained by reference to what I call an “epidemiological imaginary”: a loose set of metaphors, images, and cultural references evoking a sense of viral contagion with increasing regularity since the 1990s. The techniques, style of reasoning, and institutions addressing epidemiological phenomenon are hardly new, but the scope and power of its imaginative reach—of this way of seeing and explaining the world—appears unprecedented. The Center for Disease Control and Prevention (CDC) is a household name … and, now, an institution interested in climate change.

The use of explanations shaped by an epidemiological imaginary represents a novel and significant trend in discussions of climate change. In particular, the use of “tipping points” to explain the threat of climate change is linked to efforts to refigure how we perceive and respond to environmental danger. Efforts employing an epidemiological imaginary reshape the problem to better accommodate public health models of intervention. This paper clarifies the trend in two ways: first, by situating the multi-dimensional “tipping point” concept in popular epidemiological discourse, and second, by connecting its use to public health perspectives on climate change. As the CDC, World Health Organization (WHO), and other public health agencies make claims regarding how climate change should be perceived, understood and answered, the terms of reference familiar to an environmentalist imaginary are actively displaced (cf. Schellenberger & Nordhaus, 2004; Speth, 2004).

I proceed in the following way. First, I outline the emergence of an “epidemiological imaginary” to situate discussion of Malcolm Gladwell's (1996, 2000) “tipping point” concept. Second, I review the state of public debate on climate change to emphasize the thematic similarity of its argumentative structure to public disputes over ozone depletion. I then discuss the relative success of epidemiological references in building support for ozone regulation. Third, I reconstruct the tipping point tendency in this context. I analyze James Hansen's tipping point forewarnings in detail and discuss the use of public health models by those seeking a new way to address climate change dangers.

Emergence and Implications of an Epidemiological Imaginary

We need an epidemiology of signification …

(Treichler, 1987, p. 287)

Epidemiological discourse has become an important means of linking environmental and human health issues. The linkage is long standing though it emerges as a social antagonism, in Cox's (2006) sense, only with the environmental movement of the 1960s and 1970s (p. 45, pp. 39–66). Scholars in environmental history and environmental communication have re-illuminated this connection. Gregg Mitman (2005) and Linda Nash (2006) demonstrate the centrality of human health and disease issues to early environmental concerns as well as the distinctive importance of epidemiological understanding. Killingsworth and Palmer (1995) suggest that it was willingness to articulate these connections that made warnings from Paul Ehrlich, Rachel Carson and Lois Gibbs effective in securing wide attention (p. 1). “Popular epidemiology,” in particular, has connected human health and environmental concerns to become an exemplar case of participatory inquiry (Brown & Mikkelsen, 1997; Brulle & Pellow, 2006, p. 115; Fischer, 2000, pp. 151–157; Funtowicz & Ravetz, 1992; Trostle, 2005, pp. 153–155).

Key Dimensions of an Epidemiological Imaginary

Efforts to trace the emergence of epidemiological understanding typically begin with John Snow's (1849/1854) investigation, “On the Mode of Communication of Cholera.” In mapping the locations of sick individuals, Snow surmised that a contaminated well pump was transmitting the illness. By 1898, the threat facing Broad Street in London could collapse civilization. H.G. Wells wrote of an advanced technological society toppled by “bacteria,” or “germs of disease,” as invading Martians dominated militarily before succumbing to everyday viruses. In this case, a panic-stricken humanity is saved, but the connection to colonialism is clear. Perhaps most notable is Wells’ (1898) observation that the plot resolution should have been obvious to any levelheaded Englishman.1

It is easy to envision how general fears of plague, illness and disease would prompt suspicion of a wide range of activities and filter everyday perceptions through an epidemiological imaginary. John Berry's (2005) account of the emergence of epidemiology and virology to combat the 1918 influenza pandemic makes this point and quotes John Dewey wondering aloud in 1923 whether “consciousness of sickness was ever so widespread as it is today” (p. 393). Dewey's point is not that disease was unknown in past eras, but that an obtrusive proliferation of cures and intervention strategies has amplified such consciousness through ever-present recommendations for response. This would become the explicit goal of post World War II public health films, whose efforts to represent invisible threats through popular means of communication underwrote a scientific discourse of contagion also usable by those concerned about the effects of new mass media (Ostherr, 2005).

This provides a clue to the emergence of an epidemiological imaginary in the 1990s. In the early 1980s, select problems were reformulated as epidemics to facilitate different kinds of solutions. The asbestosis epidemic illuminated the importance of epidemiological studies to workplace safety and provided a tool to contest the organization of working conditions in human health terms. The belief that it was wrong to refuse to warn workers of danger on the basis of epidemiological evidence helped legitimate a form of understanding applicable more broadly to the social–structural conditions of everyday life. An activist version of this understanding is popular epidemiology, a form of public intervention developed “in the context of environmental struggles,” such as Love Canal and Woburn (Fischer, 2000, p. 156). Any thorough account of this discourse would need to emphasize the contributions of Berton Rouche. A New Yorker staff writer, Rouche recast epidemiological inquiry in the narrative form of detective investigations for the magazine between 1940 and 1970 and helped popularize public health perspectives. Richard Preston's The Hot Zone and Malcolm Gladwell's The Tipping Point, both of which originated as New Yorker articles, draw liberally on the dramatic narrative style Rouche established for telling epidemiological tales.2

The use of epidemiological knowledge for public intervention created cause for concern. Successful litigation had industry lobbyists trying to re-describe asbestosis lawsuits as a “plague,” and a threat of “truly epidemic proportions” to industrial practice (see Brodeur, 1985, p. 334). The malleability of the disease discourse was already apparent when psychologists admitted in the early 1970s that homosexuality had been framed as a disease. When the proliferation of meanings ascribed to AIDS illustrated how a given description of viral phenomena could advantage or discourage specific forms of funding and medical attention, the relationship between descriptive terminology and capacity to intervene became a site of public activism (cf. Erni, 1994; Treichler, 1999).

Perhaps the first obvious social problem recast systematically as an epidemic and public health concern is violence. In the early 1980s, the CDC initiated a violence prevention program and in 1985 Surgeon General C. Everett Koop declared violence an epidemic on the order of small pox to refigure violence in public health terms. Koop pointedly stated the goal: “Our focus will be clearly on how the health professions might provide better care for victims of violence and also how they might contribute to the prevention of violence” (Koop, 1985/1986, p. 4). Similar efforts were made with respect to perceptions of obesity as well: “Since the early 1980s, a relatively small group of doctors and public health officials, with substantial assistance from the weight-loss industry, has worked hard to get obesity understood as a disease” (Oliver, 2005, p. 612).

This is not to suggest public health agencies are the only sites to enroll an epidemiological imaginary. In 1985, “conservation biology” was described as a “crisis discipline,” a proposal to rethink how knowledge informs policy interventions on the model of cancer biology, a field assembling epidemiology, virology, cell biology, molecular biology, and immunology (Soule, 1985). By 1987, even cultural meaning could be viewed in epidemiological terms with Paula Treichler's studies of AIDS discourses observing “an epidemic of signification” (p. 263). Today, epidemiological discourses constitute a social imaginary, in Taylor's (2004) sense, given its capacity to reformulate “the ways people imagine their social existence, how they fit together with others, how things go on between them and their fellows, the expectations that are normally met, and the deeper normative notions and images that underlie these expectations” (p. 23).

Malcolm Gladwell's Tipping Point Perspective on Communication

In The Tipping Point, Gladwell amplifies the scope of an epidemiological imaginary to suggest all social phenomena be recast in such terms. In Gladwell's view, the “non-linearity” of an epidemiological perspective challenges naïve or commonsensical conceptions of social change. People think change is gradual, cumulative, and progressive in displaying a straightforward relationship between cause and effect or effort and outcome. Gladwell pushes hard to overturn this assumption in recognition of key moments when small shifts in human behavior result in radically altered circumstances. The case studies proving his point are often marketing or public health successes but Gladwell's favorite example is the flu virus: “In the language of epidemiologists, fifty is the “tipping point” in this epidemic, the point at which an ordinary and stable phenomenon—a low-level flu outbreak—can turn into a public health crisis” (Gladwell, 1996; Gladwell, 2000, pp. 260–261).

Gladwell's fast-paced book folds prominent elements of an epidemiological understanding into a conception of social change able to re-describe a wide range of events: drug use, crime waves, murders and even why the American Revolution succeeded. These elements include sensitivity to contextual conditions, the abrupt or dramatic nature of change, and the self-sustaining nature of knock-on style effects that perpetuate once triggered. Gladwell emphasizes these aspects to present an image of social order more amenable to intervention than we might otherwise imagine. Although society appears timeless, stable, and even inexorable at times, there is a great deal of sensitivity to perturbations that self-perpetuate and result in rapid, cascading effects. Once we accept this understanding, we learn that social problems do not require burdensome structural change, but well-timed forms of public intervention.

Gladwell's (2000) book promises guidance for such efforts through communicative principles derived from “the three rules of epidemics” or “[t]he three rules of the Tipping Point”: “The Law of the Few, the Stickiness Factor, the Power of Context” (p. 29). His imaginative extension of the epidemiological metaphor works to re-describe communication in terms of transmission mechanisms, infectious agents, and environmental conditions (pp. 18–19). The first principle is “The Law of the Few” and interprets transmission mechanisms in terms of “the efforts of a handful of exceptional people” (p. 21). The second principle is “The Stickiness Factor” and conceives communication as the viral agent of social change to recommend attention to its formal characteristics or to “simple changes in the presentation and structuring of information” (p. 25). The final principle, “the principle that makes sense of the first two” (p. 9), is “The Power of Context,” and it observes, “the smallest and subtlest and most unexpected of factors can affect the way we act” (p. 27). This is Gladwell's reformulation of his basic lesson—“a little change has a huge effect”—and his attempt to refigure society as sensitive to tipping events through communicative forms of intervention.

Gladwell's first lesson is a restatement of perhaps the oldest finding in mass communication research: “word of mouth is—even in this age of mass communications and multimillion-dollar advertising campaigns—still the most important form of human communication” (p. 32). Gladwell's (1996) early article more tightly embraced its connection to diffusion theories of communication, a body of work incorporating personal influence research to emphasize opinion leaders and change agents.3 In his later book, Gladwell (2000) creates character types to distinguish among types of personal influence. There are messengers providing multiple points of connection in social networks, or “Connectors”; messengers with new information or perspectives, or “Mavens”; and messengers who are experts in persuading despite initial reluctance, or “Salesmen” (p. 59, pp. 69–70). Although Gladwell (2000) prefers to cite Stanley Milgram and psychology research in his book, Connectors and Mavens do not build appreciably on ideas found in early communication research. However, his discussion of the sales personality usefully re-describes the idea of charismatic influence to emphasize the role of affect and non-verbal communication in defining the terms of interaction (pp. 80–86, p. 151). Gladwell's main point is clear: if you want to influence the world, focus all your resources on finding these exceptional people to carry your message for you.

Gladwell's second rule attends to message framing and, in particular, the formal features important for expressing content in an attention-getting way. His discussion mixes together marketing, children's programming, and the use of fear appeals, to characterize the problem as one of message “stickiness,” or the degree to which attention can be gained in a way that still fits sensibly into people's lives. The discussion here is dominated by a comparison of Blue's Clues puzzle solving narratives and Sesame Street's magazine format, an extended example that recommends repetitive storytelling over causal association as the way to reach children (and perhaps the way to reach people with a childlike understanding of complex problems).

Gladwell's third rule reduces to a plea to substitute contextual explanations for those attributing human behavior to genetics, personal disposition, individual will, or other non-contextual features, an important point that proved contentious when elaborated through the example of Rudolph Giuliani's crime fighting methods. The idea here is to exploit the malleability of how people perceive or describe situations. Fight violent crime by removing graffiti rather than addressing economic disparities, racism or unemployment (p. 150). The recommendation to redefine situations to advantage a preferred form of change is Gladwell's most frequent advice and the overarching theme of the book. It expresses the diagnostic and activist bend of epidemiological perspectives, though often by recommending “argument by definition,” an aspect remarked upon below.

Gladwell distills three key aspects of an epidemiological imaginary: (1) its implication in notions of the “communicable,” as suggested by Snow's (1849/1854) treatise or the early name of the CDC, Communicable Disease Center; (2) its diagnostic concern for connecting perception to pathways for public intervention; and (3) its pluralistic conception of causation as a model for social change. His account is also distinguished by its synthetic, accessible and coherent account of communication research. It is an interesting question, however, whether Gladwell's epidemiological re-stylization of communication theory is required to accept his recommendations. In fact, Gladwell's authority is generated from his meta-analytic perspective and his grounding of communicative claims in social scientific research: “To make sense of social epidemics, we must first understand that human communication has its own set of very unusual and counterintuitive rules” (Gladwell, 2000, p. 258). It is clear Gladwell embraces an anti-deliberative model of human communication comporting well with public health examples as opposed, say, to Habermas's theory. However, the connection between public health models of communication and epidemiological reasoning is unclear. Gladwell's own popularly oriented account suggests the appeal of epidemic imagery but it often reduces to recommendations for remarketing social problems, as opposed to encouraging an elucidation of how epidemiological inquiry develops as a tool for coping with urgent and uncertain circumstances.

A fuller account is needed to supplement image-based epidemic appeals with a better explanation of how epidemiological reasoning advances responses in crisis situations and Cox's (2007) discussion of “provisional validity” would usefully inform this line of thinking (p. 8). The critical research tradition inspired by Gilles Deleuze, Michel Foucault, and conceptions of “bio power” is also relevant. Treichler's (1987) epidemiology of meaning, Grossberg's (1992) notion of “affective epidemics,” and Richard Doyle's (1997) proposal to rethink rhetoric “more on the model of contagion” (p. 3), are important departure points for this analysis. Treichler's (1999) How To Have Theory in an Epidemic might prove an interesting conversation partner for those interested in Cox's (2007) crisis discipline proposal and would help steer away from the positivistic templates developed from “widely accepted narratives of past epidemics” (Triechler, 1999, p. 100).

In summary, Gladwell's concept advances an image of abrupt change that many find useful for framing forewarnings of climate change danger. Its use also signals the potential relevance of epidemiological reasoning in conditions of urgency and uncertainty, while making the involvement of public health agencies seem more plausible, normal and credible. In the next section, I outline the debate on climate change as a backdrop for the emergence of a “tipping point” tendency in forewarnings of danger.

Climate Change as Public Debate

News coverage of public debate on climate change has shifted noticeably since 2005. In that year, a USA Today cover story confidently declared, “The Debate's Over: Globe is Warming,” an article winning its author, Dan Vergano (2005), an American Geophysical Union (AGU) prize for science reporting. In 2006, The Washington Post embraced James Hansen's perspective in a lead story, “Debate on Climate Shifts to Issue of Irreparable Change: Some Experts on Global Warming Foresee ‘Tipping Point’ When It Is Too Late to Act,” in which Juliet Eilperin (2006) observed that, “[t]his tipping point debate has stirred controversy within the administration” (p. A01). Eilperin captured the shift toward “tipping point” forewarning by focusing attention on three intertwined dimensions: the possibility that change would be abrupt, irreparable, and irreversible, long before damages became clear or empirically verified. On 1 January 2007, The New York Times agreed something had changed and Andrew Revkin (2007) identified a number of scientists, “the usually invisible middle,” who were developing “a new middle stance,” which Revkin claimed was “now emerging, espoused by many experts who challenge both poles of the debate” (¶ 1, 4). Revkin did not echo Hansen's tipping point warning but he has amplified public health perspectives on climate change in the last year.

Does this shift reflect the influence of an epidemiological imaginary? Does the reframing of climate change warnings signal the ascent of public health models of intervention? Or is it simply a faddish usage, one selectively borrowing from Gladwell's own partial uptake of epidemiological vocabularies? The position presented here is based on several assumptions. I assume that the “alarmist vs. skeptics” debate characterizing US public discourse on climate change is analogous in many ways to ozone depletion debates. I then emphasize the importance of an epidemiological imaginary to ozone depletion warnings and argue for its current applicability to climate change forewarning. These assumptions are only summarily sketched here and elaborated in greater detail elsewhere.4

In reconstructing the history of public debate on climate change, most studies prefer “issue”-specific accounts. James Hansen's testimony on 23 June 1988 is frequently referenced as “the official beginning of the global warming policy debate that continues to this day” (O'Donnell, 2000, p. 109), a view affirmed in Roger Piekle's (2000) decision to situate climate change policy in relation to “Hansen's call to action” (p. 9). Studies of media coverage tend to agree. Boykoff and Boykoff (2004) justify 1988 as a starting point for public debate with reference to Hansen, and Killingworth and Palmer (1992) provide a good account of how Hansen's warning served as a point of reference for mainstream media, such as TIME magazine (pp. 155–158). Ross Gelbspan's (1997) account is typical in this respect:

Although it had lurked in the dim margins of public attention for the last few years, global warming first emerged on the public stage during the brutally hot summer of 1988, when Dr. James Hansen of NASA's Goddard Institute for Space Studies warned a congressional panel that it was at hand. (Gelbspan, 1997, p. 16)

Skeptical voices also focus on this event but it is important to acknowledge the limitations of reconstructing public debate in this manner. In treating climate change as a discrete “issue” disaggregated from other atmospheric problems, one fails to see the thematic similarity between ozone depletion and climate change debates. Studies of public understanding have long suggested this connection (for a good example, see Killingsworth & Palmer, 1992, pp. 138–139). Kempton, Boster, and Hartley (1995) provide empirical support: “the ozone hole has arrived as a concept in U.S public's consciousness, but the greenhouse effect is entering primarily as a subset of the ozone hole phenomenon, the closest model available,” a view supported by further research as well (cited in Bostrom, Morgan, Fischoff, & Read, 1994; Ungar, 1998b, p. 525). Mazur and Lee (1993), Williams and Frey (1997), and Bodansky (1994) all express similar views. Although this connection is often noted, it is interpreted variously and often used as evidence of public misunderstanding. The relevant point at present is the thematic similarity of public debates regarding warnings of danger. Consider the following features:

• The epistemic difficulty of appraising urgency in an uncertain situation regarding a problem that cannot be verified empirically as damaging until we are committed to the condition predicted to cause such damage.

• The use of computer models as a basis for issuing warnings of danger.

• The domination of public debate by voices seeking to amplify urgency (“alarmists”) or uncertainty (“skeptics”) through media savvy communication techniques.

• The political-economic influence of affected industry on policy negotiations through the direct funding of scientific counter claims.

• The hiring of skeptic scientists by US public relations firms to contest the issue.

• The direct attacks on prominent scientists’ work supporting CFC regulation and the interpretation of caveats, alternative scenarios or revised predictions in a “debunking” mode where scientists were “caught” with bad data or wrong predictions.

• The claim that ozone depletion is “only a theory” or unsupported by facts.

• The debate over natural variability or human inducement as an explanation for phenomenon.

• The concerns from the developing world that economic modernization will be inhibited.

• The claims from the developed world that an important industry and western jobs would be lost.

If these similarities are not noted, it proves difficult to make sense of James Hansen's 1988 rationale for warning of climate change dangers. Hansen (2007) now draws comparisons between ozone depletion and climate change warnings; yet it remains a little remarked fact that Hansen's 1988 warning was issued only after the empirical validation of ozone depletion warnings based on computer modeling. If the analogy between ozone depletion and climate change debate can be maintained, it suggests the importance of an epidemiological imaginary in shaping public warnings. Of course, there are different views regarding why ozone warnings were successful in articulating a “precautionary” perspective able to encourage action before verifiable damage was evident. The two most comprehensive accounts emphasize a decision made in conditions of uncertainty contrary to assumptions that bulletproof scientific truths carried the day. Benedict (1991) and Litfin (1994) ascribe different weights to diplomats and discourse patterns, respectively, but neither believes opposition was abandoned because of “the unassailable certainty of ozone science” (Gelbspan, 1997, p. 67). Gelbspan's narrative elides the manner in which ozone depletion “changed the meaning of caution” and issued in a “discourse of precautionary action” (Litfin, 1994, p. 189). As a result, experience with the problem of issuing warnings in urgent, uncertain situations is disregarded along with consideration of how metaphorical and image-based appeals proved effective in building popular support for ozone regulation.

A recovery of this context would begin in observing the effect of increasing skin cancer incidence or the role epidemiological reasoning played in those projections. Ungar (1998b) advances this perspective in arguing that ozone regulation increased its “marketability” by characterizing impacts in terms of a “hot crisis” concept. This concept develops in recognition of emerging infectious disease, like the Ebola virus, and emphasizes sensitive vulnerabilities, unpredictable dangers, and specific human impacts. Ungar finds this newly available framework for crisis is applied to ozone depletion, which, as a result, is then “meshed with extant institutional formations” (p. 521). Ungar's point underscores the main claim of this paper by illuminating how the conceptualization of complex, urgent and uncertain problems in epidemiologically inspired terms can shift perceptions of a problem to facilitate public health interventions. In Ungar's opinion, however, a successful application of the “hot crisis” concept marks the difference between ozone depletion and climate change communication (p. 513). Dimensions of ozone depletion are well suited to expression in terms of a “hot crisis,” which allows advocates to voice effective forewarnings of danger in a way acceptable to existing institutions. In this way, ozone depletion is successfully marketed and climate change is destined to flounder since the crisis represented by this problem is very different and cannot be easily expressed in such terminology (Ungar, 1998b, p. 513).

This analysis prompts two broad rejoinders neither of which should obscure the insightfulness of Ungar's work. First, it is not clear the difference between successes in ozone regulation and climate change is primarily a matter of the different marketing strategies available for communicating each problem. As McCright and Dunlap (2000) suggest, a focus on media conventions, marketability, and epistemic factors, obscures the role of political-economic power. This dimension should not be underplayed. However, in illuminating the way fossil-fuel lobbyists shape climate change discourse, McCright and Dunlap (2000) do not observe how powerful opposition did emerge to contest ozone depletion regulation. Why did such efforts fail in this case but not climate change? Was Ungar's “hot crisis” concept valuable for overcoming industry skepticism toward regulation in uncertain and urgent circumstances? One might suggest, for example, that concerted efforts by the Bush Administration to remove human health-related references to climate change acknowledges the power of this kind of connection.

Second, there are dimensions of epidemiological discourse not simply reducible to marketing savvy that may facilitate a form of reasoning useful in climate change contexts. Ungar is right to claim that “[e]ven a minimally coherent account of why climate change is a threat involves a series of loose postulates that span several scientific fields and transcend both the public's current understanding of science and the information carrying capacity of most of the mass media” (p. 522). This complexity produces a “disastrous marketing problem,” as models predict a range of weather-related consequences, none of which fit ready-made schematic models for apprehending crisis (pp. 522–523). The result is that ozone depletion warnings can be adapted to media conventions in a way climate change cannot approximate. Ozone depletion discussions can “include effects that are unique, direct, individualized and indisputable,” while climate change is unable to meet these criteria for successful communication of impact (p. 524). To his credit, Ungar acknowledges this is a post hoc explanation. Ozone depletion warnings were challenged on each of these points when regulatory action was undertaken (p. 524). If so, however, the point seems to reduce to contingent circumstance: a fortuitous model of hot crisis developed in the mid-1980s to characterize emerging threats of infectious disease and this “model of reality” was applied to ozone depletion in a way provoking widespread public concern.

Is this model still available for recognizing crisis, for prompting concern, and for generating regulatory action? If so, can climate change be expressed in such terms? Research emphasizing the connection of climate change to human disease incidence has began to emerge with regularity. In this respect, the trajectory of climate change is away from temperature shifts or extreme weather events and toward public health consequences, a trend fitting the problem to the institutional forms and cultural themes Ungar found most important for generating public interest in ozone regulation.

Tipping Point Warnings of Climate Change Danger

This is classic public health policy … . The Centers for Disease Control and Prevention is committed to addressing the public-health consequences of climate change, which is preparedness at its best. (Frumkin, 2007, ¶ 1, 4)

James Hansen began to issue public warnings of dangerous climate change in 2004. He spoke of a “time bomb,” “Humanity's Faustian Climate Bargain,” and of a “slippery slope” to climate hell, while criticizing governmental interference with these statements. These efforts drew mild attention as Hansen experimented with new metaphors and claimed that communication of danger to the public was the highest priority. In an editorial essay for Climatic Change, Hansen (2005a) explained his reasoning: “‘A slippery slope to Hell’ did not seem like an exaggeration. On the other hand, I was using ‘slippery slope’ mainly as a metaphor for the danger posed by global warming. So I changed ‘Hell’ to ‘disaster’” (p. 269).

Hansen first spoke of a “tipping point” in his 2005 address to the AGU. Given 14 months after his first public warning, the December 2005 “tipping point speech,” as one interviewer characterized it, was excerpted in the New York Review of Books and gained increased media attention in January 2006.5 As a result, further restrictions were placed on Hansen's ability to communicate by NASA's public affairs office. Hansen contacted Time Warner and The New York Times and front-page stories of government interference with climate change appeared 29 January 2006 in The New York Times and The Washington Post. The Washington Post and then Time, 60 minutes, and other media mentioned this tipping point aspect prominently.

Hansen spoke of tipping points to describe an irreversible change implying consequences that are undesirable because they are uncontrollable and uncertain: “we are on the precipice of climate system tipping points beyond which there is no redemption” (2005b, p. 8).6 There are abrupt, self-sustaining changes induced by minor shifts at sensitive points of intervention, a view suggested by scientific concepts like thresholds, feedbacks, and forcings. Hansen's explanation parallels Gladwell's account in seeking to distinguish this view from gradual, cumulative kinds of change. However, the term appears only four times in his 2005 AGU lecture and it is absent from his accompanying slides. Less than two years later, however, tipping points represent Hansen's main justification for taking immediate and specific actions on climate change.

Hansen's understanding of tipping points is conveniently fixed in his testimony to the State of Iowa Utilities Board in 2007. This testimony includes the discussion and the Power Point slides used in his public lectures. It was solicited to support deliberations regarding the threat represented by climate change in the context of a decision on whether to build new coal energy generating stations in Iowa. Hansen's warnings include the use of stratospheric ozone regulation as a model, an imprecise definition of tipping points, an expansive use of the term, and an apparent deviation from the primary scientific research in issuing the warning.

First, Hansen models his proposed solution on the example of ozone depletion regulation. His understanding of why the ozone model might work is not naïve, though perhaps idealistic in its reconstruction of how scientifically grounded policymaking should work. Hansen spreads the blame for communicative failures to include media, government, special interests, the public, and also scientists, in claiming that, “we as scientists have not done as good a job in making clear the threat to the planet and creation” (p. 30). Ozone regulation is provided as an example of a good job.

Second, in trying to make clear the threat to the planet, Hansen describes tipping point change in the following manner: “A tipping point occurs in a system with positive feedbacks. When forcing toward a change, and change itself become large enough, positive feedbacks can cause a sudden acceleration of change with very little, if any, additional forcing” (p. 3). This explanation accords well with Gladwell's attempt to capture changes that are sensitive to small perturbations and which self-sustain the pattern of change without further forcing. In this situation, one passes the “threshold” where past climate responses are a reliable guide to future predictions. This is also the explication Gabrielle Walker (2006) found acceptable in her review of tipping point uses in climate change science for Nature. It is an accelerated change against a background of slower or more gradualist change that distinguishes a tipping point. This creates imprecision since the rate of change is only accelerated when pictured upon a more gradually shifting set of relations. Hypothetically, the “tipping point” might be a snap of the fingers or a century long moment, if considered on geological timescales. In practice, however, the intent of tipping point warnings is to transform our perception of climatic and geological system change by using more familiar “event”-based frames of reference. Imprecision does not result simply from the complexity of the processes involved, but from the effort to fit these almost imperceptible changes to temporal scales based more firmly in typical human experiences. Put another way, Hansen is re-characterizing climatic processes in terms of events so as to recalibrate the dangers represented by shifts in these processes to our sense of significant change. This entails a necessary transformation of scientific research and opens Hansen to charges of alarmism.

Third, this warning becomes more confused when tipping points are used indiscriminately to explain changes in physical processes, life systems, and social behavior. Such slippage is frequent in climate change discussions and, at worst, entails the reduction of complex social behavior to physical or biological models in a positivistic fashion. Hansen's discussion of tipping points in biological systems simply refers us to the uncertainty characteristic of ecological systems characterized by multiple points of causality that, if altered, might well precipitate massive extinctions (p. 4). The application of tipping points to social change and public opinion formation is associated rather facilely with the idea of a “snowball effect” (p. 5). Hansen is building on a characteristic understanding among climate scientists regarding how the social world changes. For instance, Walker (2006) cites IPPC author, Richard Alley, “human tipping points are probably more important than the natural ones” (p. 805). Similarly, an editorial comment by Nature advocates directly for Gladwell's book and states that, “[t]he concept of the tipping point is, in fact, more pertinent to the climate crisis in the social sphere than in the physical world” (2006, p. 785). However, the understanding of tipping point conceptions of social change is remarkably weak. It is never elaborated and the glowing references to Gladwell's book are surprising for scientifically trained professionals, since the book never considers counter examples and non-confirming evidence. However, Hansen's understanding of social tipping points is typical in this respect. He believes that a refusal to build new coal generating plants in Iowa might send a “message,” one able to reframe perceptions of climate change and serve as a tipping point for new mass behaviors (pp. 3–5).

Finally, there is the fact that Hansen's use of “tipping points” does not simply reflect the primary science. I replicated the methodology used by Naomi Oreskes’ (2004) to survey the climate change research literature and found no uses of “tipping point” between 1993 and 2003. I then extended the search through the end of 2006 and broadened the parameters. This resulted in two research articles. The dearth of tipping point references in the scientific literature prompts questions regarding its accuracy as a description of climate change. In addressing this question for Nature, Gabrielle Walker (2006) reviewed the scientific literature and interviewed IPCC climate scientists to conclude there are several “danger zones that may deserve to be called tipping points” (p. 802). In particular, the elements of threshold crossing, irreversibility, and positive feedback appear to characterize key climatic mechanisms quite well. It is odd, however, that Walker's non-committal conclusion suggests the popularity of the concept, while failing to observe its very rare use in the primary research literature (p. 802). In fact, both Walker and an accompanying Nature editorial are unclear on this point. As the Editor's Summary (2006) puts it,

The idea that passing a hidden threshold could drastically worsen man-made climate change has been current in the scientific literature for many years. Now it has a new name, a “tipping point,” and suddenly the news magazines and other media have picked up on it. (¶ 1)

This is an important point. If tipping point warnings do not simply reflect advancing scientific understanding, then why is it now preferred? There are other functionally equivalent and more clearly elaborated conceptions of change available, both in the scientific literature and in popular environmental writing. For example, Al Gore's (1992) Earth in the Balance attempts to revise received views of causality in a way very similar to Gladwell's perspective, enrolling ideas of non-linearity from chaos theory (p. 34, pp. 361–363). Walker does not say it is an inaccurate description of climate systems and the editors of Nature suggest its use is akin to old wine in new bottles. The perspective is almost nominalist in its conclusion regarding the appropriateness of tipping points. Climate systems might be described in a variety of manners, either using tipping points or other concepts. Its importance derives not from better describing climate systems but in making available an image of crisis useful for registering public concern and opening avenues for response.

It is on this point that advocates and critics of tipping point forewarnings disagree. The editors of Nature, for example, believe “there are three dangers attendant on focusing humanity's response to the climate crisis too much on tipping points” (p. 785). They believe such warnings underplay the uncertainties inherent to climate science, that they distort human responses by focusing on avoidance rather than adaptation, and that “can induce fatalism,” since tipping points, “may encourage a belief that a complete solution is the only worthwhile one, as any other course may allow the climate system to tumble past the crucial threshold” (p. 785).

It is easier to discuss the meaning of tipping point warnings more fully if the problem motivating Hansen's usage of tipping points is better understood. A central dilemma facing climate change communication is the incommensurability between problem formulations and available solutions. Most warnings emphasize the scale, scope and magnitude of the problem in a manner that devalues conventional ways of responding to environmental concern. This observation has produced various responses. Some claim this situation requires the death of environmentalism since conventional environmentalist responses rule out the kinds of change needed (cf. Schellenberger & Nordhaus, 2004). Others claim the situation is the result of “climate porn,” where alarmists and their audiences respond to the “secretly thrilling” experience of crisis in a detached manner (Ereaut & Segnit, 2006). The “climate porn” manner of dismissing environmental concern resembles the charges of environmental hysteria outlined by Killingworth and Palmer (1995), especially in the worry that alarmist warnings might spread like an epidemic (p. 2). A perverse human desire outstrips rational judgment in motivating such alarmist warnings and, as a result, the scenarios promoting urgency are vivified and exaggerated to the point that any possible human response seems inadequate. Society, as a result, “tips” into a defeatist or fatalist trajectory.

These are two popular ways to make sense of the problem/solution incommensurability characteristic of climate change warnings: as the result of imaginative deficiencies or perverse desire. Yet, it seems impossible to rule out on principle the idea that some problems will outstrip available responses. In this respect, the “climate porn” claim is particularly weak. It originates from a desire to chart a middle position between alarmism and skepticism, a perspective hoping to treat climate change seriously while bending problem formulations toward manageable solutions based typically in a public health understanding. This goal, for example, guides Britain's influential Tyndall Center for Climate Change Research. Its director, Mike Hulme (2006), claims a “discourse of catastrophe” has “pushed the debate between climate change scientists and climate skeptics to now being between climate change scientists and climate alarmists” (¶ 13). Hulme attributes this shift to Tony Blair's tipping point warnings at a government convened conference: “By stage-managing the new language of catastrophe, the conference itself became a tipping point in the way that climate change is discussed in public,” a shift so pronounced Hulme concludes that, “the discourse of catastrophe is in danger of tipping society onto a negative, depressive and reactionary trajectory” (¶ 21).

Hulme develops two arguments to support disciplining public communication of climate change dangers. He draws a strong distinction between the language of catastrophe and the language of science to ask why people like Blair or Hansen “are openly confusing the language of fear, terror and disaster with the observable physical reality of climate change …”(¶ 11). Hulme implies it is dishonest to redefine climate change in this way, since it “hides a cascade of value-laden assumptions which do not emerge from empirical or theoretical science” (¶ 26). The obvious conclusion is that all climate change action is based in value assumptions. Recommendations for social change should be debated in terms of human values, not presented as the logical outcome of a scientific demonstration.

Hulme does not pursue this conclusion and instead develops a second argument regarding the utility of alarmist styles of communication. An alarmist school of thought holds that urgent warnings are necessary to gain attention and motivate behavioral change. As Killingsworth and Palmer (1992) put it, the “lash of crisis” can more rapidly advance cultural change on environmental issues, even if the depth of the resulting commitment might be questioned (p. 156). This belief would seem to underwrite warnings of extreme disaster and catastrophe. Like the editors of Nature, Hulme believes these warnings are ineffective.

The language of fear and terror operates as an ever-weakening vehicle for effective communication or inducement for behavioural change. This has been seen in other areas of public health risk. Empirical work in relation to climate change communication and public perception shows that it operates here too. (Hulme, 2006, ¶ 28–29)

The main point for the purposes of this discussion is Hulme's implicit redefinition of climate change as a public health issue. This reframing implies a cascade of value-laden assumptions no less than the position of proponents preferring an alarmist form of warning. Redefining climate change as a public health issue is “argument by definition,” and like Hulme's alarmist opponents, it advances a set of values without arguing for them explicitly.7 A public health perspective is no more implied by the empirical and theoretical climate science than alarmist perspectives. Instead, Hulme's views are based in an image of science, an assumption about the institutions having authority to define climate change dangers, and a theory of how communication can work to encourage preferred responses.8 This is evident in one of the Tyndall Center's useful briefing reports on climate change communication.

What is clear, however, is that the problem must be made tangible and manageable if the warnings are to have a real impact. Given current representations, the solutions to such a vast and complex problem make the public's response seem insignificant, futile and in some cases too late to make a difference … . (Lowe, 2005, p. 4)

All popular efforts to inform the public through climate change communication wrestle with a set of complex assumptions regarding how best to fit perceptions of the problem to recommended avenues for solution. These efforts invariably balance the desire for precise and accurate scientific representations with an appraisal of the best available means of persuasion for encouraging an effective response. It is these appraisals, I have suggested, which are increasingly shaped by an epidemiological imaginary and a belief that public health institutions can, as Lowe (2005) puts it, “have a real impact” (p. 4).

In this respect, Hansen and Hulme embrace the same theoretical perspective. Both believe communication can induce social change by tipping behaviors along specific trajectories through warnings of danger. Hulme wants to discipline public warnings to accord more with the image of science and public health practice he holds. In this sense, climate change would be invoked to normalize a set of behaviors rather than startle or provoke new behaviors. But the difference is not vast for two reasons. First, if a tipping point for dangerous climate change is crossed, then discussion will necessarily adopt a vocabulary of adaptation and coping, since avoidance is no longer possible. Hansen's own estimation put this tipping point around 2015. Second, the idea that tipping point warnings will induce fatalism is far from evident and represents a misunderstanding of Gladwell's main point. It rests on the view that defeatism is a logical response when faced with an insurmountable obstacle. If we want to avoid defeatism, we must avoid representations of climate change characterized by problem formulations incommensurate to available solutions. However, Gladwell's perspective is grounded on the belief that such incommensurability should not inspire fatalism. This is the main argument of the tipping point perspective: Small shifts result in massive social changes all the time. We should not seek comprehensive solutions, but experiment with “band-aid” responses, since these actions often have disproportionate and counterintuitive effects (Gladwell, 2000, pp. 256–257).

Conclusion

The manner in which an epidemiological imaginary might refigure perceptions of climate change is a complex question. The confidence with which weakly elaborated views of social change underpin prominent climate change communication perspectives suggests its scope and power, as do the now proliferating recommendations for pursuing public health models of response. James Gustave Speth's (2004) recent work provides a good example of how epidemiological terminology re-conceptualizes the way we perceive and intervene in climate change dangers. Speth has long been involved in environmental affairs from an impossibly diverse array of perspectives: Think-tank and interest group (WRI, NRDC), Presidential advisor (Carter, Clinton), international governance (UNEP), even formal education (Dean of Forestry & Environmental Studies at Yale). As a result, Speth's proposal to rethink environmental problems from the perspective of solutions currently available is less surprising than the way a new warning of climate change danger is thought to advance this perspective: “Here is the way I would characterize the response to global threats to date: a highly threatening disease is attacking our planet …” (p. 98). Speth's use of tipping points is limited to re-describing how and why 1970s environmentalism achieved successes in domestic regulation (p. 82). However, his recommendations for communication are classic public health campaigns:

All those who can influence what public service ads make it onto the airwaves can help us reach the public on climate, as happened with drunk driving, drugs, smoking, and HIV/AIDS. We need a climate awareness campaign modeled on these efforts. (Speth, 2004, p. 228)

The recent efforts of the CDC provide an even more obvious example. Andrew Revkin's (2007) discussion of the emerging middle position in climate change debate used Hulme's perspective as representative. Howard Frumkin (2007), a director and epidemiologist for the CDC, wrote in response to Revkin's article, “This is classic public health policy … The Centers for Disease Control and Prevention is committed to addressing the public-health consequences of climate change, which is preparedness at its best” (¶ 1, 4). As public health agencies like the CDC promise to play a leading role—its Director of the National Center of Health Marketing Julie Louise Gerberding plans to speak of “climate change” in every speech—this attention is likely to further amplify the popular embrace of an epidemiological imaginary for expressing environmental dangers.

The immediate consequence will be the “pegging” of climate change news stories to human health concerns. Previously, climate change made the news in connection with odd weather patterns. This shift to human health dimensions has been disadvantaged by the removal of such references from US government agency reports on climate change, but that may well change in 2009 when the Bush Administration leaves office. News media have also been more vigilant about reporting such changes and the recent editing of Gerberding's CDC testimony to this effect has drawn significant attention to the problem. It is also important to note that few subfields of communication have grown as rapidly as health communication in recent years. It is not difficult to imagine the well-funded research into smoking, cancers and drug use could expand to include climate change communication. This would have the likely consequence of normalizing climate change as an issue to be addressed in terms of reducing specific risks in a defined population.

The popular embrace of an epidemiological imaginary for expressing environmental dangers should not be a surprising trend. These models of explanation have proven remarkably promising as a tool for guiding practical interventions in uncertain and unfamiliar situations. However, the support of epidemiological imagery for public health interventions will promise little more than a new form of positivism if the slippage in application from physical to human phenomena is not more closely studied and if its unique form of reasoning is not better elaborated for non-specialists. In this respect, the focus on environmental crisis as an object of inquiry for environmental communication scholars is a promising avenue.9

Additional information

Notes on contributors

Chris Russill

Chris Russill is an Assistant Professor in the Department of Writing Studies at the University of Minnesota

Notes

1. See Chapter 8, “Dead London.”

2. It is worth mentioning that Rachel Carson's Silent Spring was first serialized in The New Yorker. Elizabeth Kolbert's Field Notes from a Catastrophe and Bill McKibbon's End of Nature also appeared as articles in the magazine, as did Paul Brodeur's early reporting on asbestosis.

3. In fact, early diffusion of innovation studies also conceptualized personal influence and public opinion as contagion like processes (cf. Rogers, 1995, pp. 301–302).

4. This draws from a longer discussion of the thematic similarity of ozone depletion and climate change found in Russill (2007).

5. See, for example, James Hansen's interview with Frontline, retrieved November 11, 2007 from http://www.pbs.org/wgbh/pages/frontline/hotpolitics/interviews/hansen.html.

6. In this respect, Hansen differs from Rachel Carson's views regarding the control of nature, despite their similar uses of apocalyptic warnings. Regarding Carson, see Killingsworth and Palmer (1995, p. 11).

7. For a valuable discussion of argument by definition, see Schiappa (2003, pp. 130–131).

8. See Killingsworth and Palmer (1992) for a good discussion of how images of science are affirmed in popular media.

9. See the first issue of this journal, in particular Cox (2007) and Schwarze (2007).