The Ethics of Belief, Cognition, and Climate Change Pseudoskepticism: Implications for Public Discourse

2.1 Ignorance of the scientific process

When it comes to ignorance regarding the process of modern science, a contributing factor to pseudoskepticism may be the Dunning–Kruger effect. This effect occurs when one lacks sufficient knowledge of a topic to accurately judge the depth of one's own ignorance on that topic (Kruger & Dunning, 1999). In such cases responsible awareness of one's own epistemic limitations may give way to unwarranted confidence in one's ability to critique the findings of professionals. Pseudoskeptics caught in the Dunning–Kruger effect may not wish to reject science at all—they may even consider themselves scientifically astute—but their ignorance of how modern science works can lead to an inflated view of their own ability to judge technical matters.

2.2 Ideologically motivated reasoning

Tension between the ideological beliefs, and values, important to one's cultural identity and the findings of modern science play an important role in pseudoskepticism. This form of pseudoskepticism is often exhibited by those with a commitment to free-market ideals when assessing the robust evidence for anthropogenic global warming (Dunlap & Jacques, 2013; Dunlap & McCright, 2010, 2011; Lewandowsky, Oberauer, & Gignac, 2013a; McCright & Dunlap, 2011a,b; Oreskes & Conway, 2010). Ideologically driven pseudoskepticism may also be religious in nature, as in the rejection of evolution by natural selection. Yet a distinction exists between religiously reasoned pseudoskepticism and the faith-based “suspension of disbelief” discussed above. Religiously driven pseudoskepticism leads to motivated reasoning in favor of ideology preserving conclusions. In contrast, faith-based science denialism depends on an arational exercise of faith, which need not involve attempts to reconcile one's belief to scientific evidence (such efforts might even be viewed as antithetical to one's faith).

All forms of science denialism involve selective validation of some scientific conclusions while rejecting others. This is understandable since living in a modern world influenced everywhere by science and technology makes it impossible for science deniers to function without sustained cognitive dissonance. Pseudoskepticism is no different in its displays of selective validation. In the case of pseudoskepticism an odd twinning of extreme credulity and cynical disbelief is particularly pronounced since pseudoskeptics seek to both deny accepted science and adopt the authority of scientific skepticism. For instance, pseudoskeptics may aggressively criticize an established scientific consensus while uncritically referencing non-scientists who assert unsubstantiated claims (Elsasser & Dunlap, 2013). To fully understand pseudoskepticism and its relationship with pseudoscience, it is necessary to examine the distinction between pseudoskepticism and scientific skepticism.4

2.3 Scientific skepticism and scientific consensus

Scientific skepticism, or reasoned skepticism, is a vital component of the modern scientific process (Merton, 1942, 1973). Indeed, the scientific process is distinguished, in part, by the methodological application of skepticism, aimed at the most evidentially warranted understanding of natural phenomena. Clearly understanding the skeptical process of science allows for better appreciation of why disregarding scientific consensus (a defining feature of pseudoskepticism) is epistemically unwarranted and a key aspect of pseudoscience.5

The scientific skepticism of modern science is applied by a community of inquirers; it is not enough that one researcher endorse a particular conclusion, for scientific findings must be confirmed repeatedly by other scientists (if they are to gain traction in the broader scientific community). Part of what scientists do is to test conclusions, examining and when warranted rejecting them, before they are accepted as established. In this sense, the scientific process represents a form of empirical contest. When an overwhelming scientific consensus among active researchers in a field exists, it is often because attempts to disprove a particular claim have instead converged to strengthen its credibility. This is not to say that any claim, strictly speaking, can be formally falsified or verified. There will always be a large background of scientific hypotheses and concepts bundled together in support of any particular consensus, which in turn resist logically formal justifications (Harding, 2013; Quine, 1951). When a consensus view does exist, it signals that the consensus view functions reliably, under a wide range of skeptically informed empirical applications, to predict and explain observational results (Cook & Lewandowswky, 2016; Hahn, Harris, & Corner, 2016).

Non-experts hold a considerable disadvantage with regard to methodological training and experience, but rather than realizing this, pseudoskeptics may take their lack of training as a virtue. A virtue that, or so they may believe, frees them from the traps of professional “groupthink.” For this reason, non-experts wishing to deny anthropogenic global warming sometimes reference historic figures like Galileo as evidence that a scientific consensus can be wrong.6 Yet figures like Galileo and other thinkers of his time are responsible for ushering in the modern age of experimental research that has driven the very need for advanced-level training separating professional researchers from the lay public. It is consistent with the Dunning–Kruger effect that those evoking Galileo and other historic figures do not know enough about science, and its history, to understand the error of their comparison.

Consequently, when we refer to the denial of well-established scientific consensus as skepticism, we invite confusion. Overgeneralizing and misusing the term skepticism is damaging to informed public discourse in at least two ways: (a) Insofar as many people have a nebulous sense that skepticism is good, pseudoskeptics win a rhetorical advantage by portraying themselves as skeptical in contrast to “mainstream” scientific research, which they portray as dogmatically set against their skeptical challenge. (b) Because reasoned skepticism is a crucial component of the scientific process, misuse of the term skepticism—to mean any form of doubting something, for any reason—chips away at an understanding of how science actually works, which should be regarded as the core of scientific literacy (Holbrook & Rannikmae, 2009). This point is important because in cases of science denial not explained by motivated reasoning or ideological bias, the rejection of settled science may simply involve ignorance of the scientific process and the epistemic significance of consensus in science (Cook & Lewandowsky, 2016; Galesic, Kause, & Gaissmaier, 2016; Hahn, Harris, & Corner, 2016; Joslyn & LeClerc, 2016; Newell et al., 2016; Ranney & Clark, 2016). Thus, one of the dangers of pseudoskepticism is its potential to mislead the uninformed.

2.4 Pseudoskepticism and the public sphere

To be clear, disagreements about policy and ensuing debates only involve pseudoskepticism to the degree that relevant scientific consensus is denied in the context of policy decisions. Strictly speaking, the term pseudoskepticism is most reasonably applied to rejections of established scientific consensus only—not widely recommended public policy or popular political opinions. Yet science and its findings are woven into most every aspect of our lives and sustainable modern democracies require informed publics, able to make the distinction between data skeptically vetted through authentic peer-review, and ideologically inflected claims that are made directly to the public, often bolstered by the support of like-minded institutions (Brulle, 2013; Dunlap & Jacques, 2013; Dunlap & McCright, 2010, 2011; Oreskes & Conway, 2010; Pfau, Haigh, & Wigley, 2007). It is crucial then that public disagreement with a scientific consensus must be accompanied by the honest acknowledgment of such consensus to avoid the charge of pseudoskepticism. Acknowledging well-established science (Rawls, 1993, 1997, 2001) and resulting scientific consensus is a requirement of responsibly applied public reason. (Torcello, 2011, 2014b).7 The concept of public reason is discussed further below (Section 'Public reason and the importance of referencing scientific consensus in public discourse').

2.5 Pseudoskepticism and pseudoscience

The importance of skepticism to science stands in stark contrast to pseudoscience. One identifying feature of pseudoscience is circular belief. In other words, circular acceptance of a contentious claim guides the pseudoscientific pursuit. Thus, for instance, “investigators of the supernatural” assume the existence of “supernatural” phenomena beforehand, which encourages confirmation bias and motivated reasoning in support of their preconceived conclusions.8 The absence of any reliably established justification for such endeavors encourages motivated reasoning, emphasizing anecdotal evidence, the discounting of established scientific vetting, and the existence (or epistemic weight) of scientific consensus. The skeptical process of scientific analysis is procedurally designed to protect research from motivated reasoning of this sort.

The scientific process does err, it should be emphasized, but it also self-corrects over time (Merton, 1942, 1973). Again, it is this process of progressive self-correction that relies upon robust genuinely skeptical methodologies. Those who challenge the view that science is necessarily self-correcting, in doing so, can even play a role in the long-term trend of scientific critique and self-correction (Ioannidis, 2012).

I therefore want to insist on the term pseudoskepticism as a more accurate label for describing the rejection of scientific consensus based on ideologically driven reasoning, or on the grounds of some formless preference for contrarianism or cynicism parading as scientific skepticism (Torcello, 2011, 2012, 2014b). It is worth emphasizing that pseudoskepticism, as I formulate the concept, is a species of science denialism but not a synonym for science denial.9 Pseudoskeptics attempt to portray themselves as scientifically objective while they depict mainstream scientists as credulous dogmatists. Pseudoskeptics are unique among science denialists in their attempt to reject science while appropriating the epistemological authority of science and scientific skepticism. In this way pseudoskepticism is akin to pseudoscience in that both run contrary to the very conceptions from which they contrive their justifications (i.e., pseudoscience disavows the methodological constraints of modern science while seeking the approbation of science. Pseudoskepticism seeks to critique scientific consensus as uncritical, or fraudulent, while ignoring the extent to which rigorous methodological skepticism informs modern scientific consensus).

Moreover, pseudoskepticism is a key feature of pseudoscience, but it need not be part of any broader pseudoscientific effort. For instance, any given practitioner of pseudoscience (e.g., a homeopathic practitioner) will exhibit a degree of pseudoskepticism with regard to modern science (e.g., modern medical science and physics), but it does not follow that pseudoskeptics necessarily promote a larger pseudoscientific agenda.10 Therefore, pseudoskepticism should be defined more narrowly than either science denialism or pseudoscience. I propose therefore that pseudoskepticism be recognized as a subspecies of science denialism and an essential element of pseudoscience.11

2.6 Pseudoskepticism, belief formation, and morality

Likewise, the problem of pseudoskepticism goes straight to the crux of the relationship between belief formation and morality. A major danger of pseudoskepticism, as well as of pseudoscience, is its role in the development of socially generated ignorance.12 Examples of the harm related to such ignorance include the following: (a) South Africa's failure to respond appropriately to its HIV/AIDS epidemic under the leadership of former president Thabo Mbeke. The Mbeke administration's denial of the well-established link between HIV and AIDS may have contributed to an estimated 365,000 deaths between 2000 and 2005, in the absence of timely antiretroviral programs (Chigwedere, Seage, Gruskin, Tin-Hou, & Essex, 2008). (b) Outbreaks of otherwise preventable and potentially eradicable diseases may result from ignorance and active disbelief regarding the well-established safety of childhood vaccination programs. Countries with active anti-vaccination campaigns, or that lack robust policy requiring childhood vaccinations, have lower rates of vaccination and significantly higher rates of vaccine-preventable disease (Gangarosa et al., 1998). Furthermore, there is a significant correlation between geographic regions where greater numbers of parents resist vaccinating their children and the occurrence of vaccine-preventable outbreaks (Atwell et al., 2010).

2.7 Pseudoskepticism and anthropogenic global warming

I want to concentrate now on what I take to be the most pressing example of pseudoskepticism: the denial of anthropogenic global warming. The United States is the world's leading producer of GHG emissions per capita, followed by a number of other wealthy nations (The World Bank, 2013). A variety of traditional ethical perspectives converge on the conclusion that the United States, and other wealthy polluting nations, should take a leading role in responding to challenges of global climate change (Caney, 2010; Cuomo 2011; Gardiner, 2006, 2011; Jamieson, 2010, 2014; Nussbaum, 2013; Posner & Weisbach, 2010; Shue, 2010; Singer, 2004, 2006; Torcello, 2011). Yet the United States has the highest level of climate pseudoskepticism among both private citizens and publicly elected officials (IPSO MORI, 2014). News media outlets, especially in the English-speaking world, mention anthropogenic global warming relatively infrequently, often providing equal time for pseudoskeptical views (Boykoff & Bokoff, 2004; Boykoff, 2007; Jones, 2014; Painter, 2011; Santhanam, 2014). Under these conditions, even among U.S. citizens who accept anthropogenic climate change, there exists a widespread belief that climate change poses no significant threat within one's own lifetime and that the causes of climate change remain scientifically controversial (Butler & Pidgeon, 2009; Jones, 2014; Painter, 2011).

Such perceptions are dangerously out of step with reality. Active climate researchers overwhelmingly conclude that global warming is the result of human behaviors (Anderegg, Prall, Harold, & Schneider, 2010; Cook et al., 2013; Doran & Zimmerman, 2009; Oreskes, 2004). In addition, as Antarctic and Greenland ice sheets continue to melt, coastal cities are increasingly vulnerable to storm surges and flooding (Parris et al., 2012). This means that misinformation regarding climate change has serious implications for public safety if allowed to influence policy decisions. To make matters worse, much of the climate change misinformation circulating in the public realm has been introduced through organized, corporate-funded campaigns of disinformation. These vested interests leverage their political influence in the form of lobbyists, policy think tanks, and political funding (Brulle, 2013; Dunlap & Jacques, 2013; Dunlap & McCright, 2011; McCright et al., 2016; Oreskes & Conway, 2010). Citizens misinformed about the human causes, and resulting risks, of climate change are unlikely to pressure politicians to address the problem through policy action. It is, therefore, important to recognize climate pseudoskepticism as a key element of the United States’ failure to take meaningful action to curb carbon emissions during the last 30-year period (Ding, Maibach, Zhao, Roser-Renouf, & Leiserowitz, 2011; McCright, Dunlap, & Xiao, 2013).

3.1 The ethics of belief

Clifford begins with the following example:

A shipowner was about to send to sea an emigrant ship. He knew that she was old, and not ever-well built at the first; that she had seen many seas and climes, and often had needed repairs. Doubts had been suggested to him that possibly she was not seaworthy. These doubts preyed upon his mind, and made him unhappy; he thought that perhaps he ought to have her thoroughly overhauled and refitted, even though this should put him at great expense. Before the ship sailed, however, he succeeded in overcoming these melancholy reflections. He said to himself that she had gone safely through so many voyages and weathered so many storms that it was idle to suppose she would not come safely home from this trip also. He would put his trust in Providence, which could hardly fail to protect all these unhappy families that were leaving their fatherland to seek for better times elsewhere. He would dismiss from his mind all ungenerous suspicions about the honesty of builders and contractors. In such ways he acquired a sincere and comfortable conviction that his vessel was thoroughly safe and seaworthy; he watched her departure with a light heart, and benevolent wishes for the success of the exiles in their strange new home that was to be; and he got his insurance-money when she went down in mid-ocean and told no tales. (Clifford, 1887)

Clifford makes clear that the tragic ending is irrelevant to the ethical conclusions one ought to draw from this case, for these conclusions would hold even if the ship had made the voyage successfully. The question, rather, is whether or not the ship's owner was justified in believing that his ship was seaworthy. One might object that it is not the owner's belief that caused the tragic outcome, but his failure to maintain his ship properly. After all, it is possible that one would believe in the safety of one's ship and still go through responsible procedures of maintenance and inspection. This counterargument fails to contradict Clifford's point, though, since such an owner would have a warranted belief in the soundness of his ship.

Getting further into the portrayal of epistemic warrant, Clifford presents a second example involving the reckless dissemination of misinformation. In this example, a rumor is spread through a community, to the effect that certain teachers are conniving to have children removed from their legal guardians to indoctrinate them into a particular religious sect.

Clifford's text is once again worth quoting at length:

There was once an island in which some of the inhabitants professed a religion teaching neither the doctrine of original sin nor that of eternal punishment. A suspicion got abroad that the professors of this religion had made use of unfair means to get their doctrines taught to children. They were accused of wresting the laws of their country in such a way as to remove children from the care of their natural and legal guardians; and even of stealing them away and keeping them concealed from their friends and relations. A certain number of men formed themselves into a society for agitating the public about this matter. They published grave accusations against individual citizens of the highest position and character and did all in their power to injure these citizens in the exercise of their professions. So great was the noise they made that a commission was appointed to investigate the facts; but after the commission had carefully inquired into all the evidence that could be got, it appeared that the accused were innocent. Not only had they been accused on insufficient evidence, but the evidence of their innocence was such as the agitators might easily have obtained, if they had attempted a fair inquiry. (Clifford, 1887)

The issue for Clifford is not whether those involved in the two examples were sincere in their beliefs, but whether the beliefs were formed through responsible investigations or, instead, by motivated reasoning. In both cases, it is possible to determine the difference, through serious consideration of how evidence was gathered and examined. Epistemic warrant attends only the analysis of evidence garnered carefully and understood for the causative links it tentatively confirms or falsifies.

Clifford's illustrations lend themselves to modern examples of climate science pseudoskepticism. The first example straightforwardly involves one person risking the safety of others over dubious beliefs arrived at through motivated reasoning. In keeping with the spirit of Clifford's example, take the inevitability of sea level rise from climate change. Even conservative estimates of sea level rise resulting from climate change implicitly place a large number of the world's coastal poor at increased risk of losing their property as well as their lives (IPCC, 2013). Politicians in nations responsible for the majority of GHG emissions who allow ideologically motivated reasoning to justify their denial of anthropogenic climate change treat those most vulnerable to sea level rise as Clifford's ship-owner treated his seafarers. In both cases, unwarranted beliefs contribute to people's willingness to risk the safety of innocent others.

Clifford's second example parallels climate science pseudoskeptics who slander climate scientists and others working on topics related to climate change. It is routine for pseudoskeptical climate bloggers to accuse scientists of fraudulent research and data manipulation (Clynes, 2012). In 2009, famously, emails were stolen from Britain's University of East Anglia Climate Research Unit. The emails were released online along with accusations that climate researchers were engaging in fraudulent activity. Subsequent investigations repeatedly demonstrated the innocence of those climate researchers, though to this day, many in the public know only of the accusations against and not of the vindication of the scientists (Fischer, 2010). Such behavior puts researchers at risk of not being able to do and disseminate their work by slandering their reputation.

Clifford takes a hard line, arguing that “it is wrong always, everywhere, and for anyone, to believe anything upon insufficient evidence” (1877). Elsewhere, I examine the viability of so categorical a conclusion (Torcello, 2011, 2014b), but here it is not necessary to delve into an extended philosophical or textual examination. It is enough to recognize Clifford's key claim, that our beliefs carry a moral relevance that is often overlooked. In addition, one can profitably acknowledge that the values influencing our beliefs have moral implications. Clifford helps us to consider how even everyday beliefs, most commonly considered a matter of personal prerogative, animate far-reaching behaviors that impact the lives of others. The claim I wish to advance upon the back of Clifford's argument is that our beliefs always involve a degree of moral hazard (Torcello, 2011, 2014b). In other words, our beliefs entail risks that may expose innocent people to harm from which we are insulated and that we cannot predict. Such a claim, explored below, is supported by the very premises Clifford uses to advance his stronger, more controversial conclusion about morality and epistemic warrant.

3.2 Clifford's premises and science communication

Clifford's argument depends on the truth of the following two premises regarding the formation of our beliefs and their social influence:

P₁: Any given belief will set the cognitive conditions for related beliefs to follow.

P₂: Our beliefs carry a social influence that we cannot easily control or predict.

The first premise (P₁) suggests that we should consider our beliefs as part of a larger cognitive web. This view is consistent with a position referred to by contemporary philosophers of mind as mental holism. On this view, individual beliefs derive meaning in the context of a holistic web of related background beliefs (Block, 1995, 1998; Quine, 1951). It does not follow from this that all of our beliefs will be rationally consistent. Instead, it suggests that our beliefs are related through patterns of reasoning suggestive of a consistent cognitive style, but not necessarily by rationally consistent content. Philosophers have long argued that one set of beliefs will contribute to the cognitive conditions for related beliefs to follow.13 This is the raison d’être behind efforts to instill a strong understanding of logic and critical thinking in our students.14 It has also been long acknowledged by philosophers that our attitudinal and value beliefs influence our perception and understanding of the larger world (Engelhardt, 1996; Kitcher, 2001; MacIntyre, 1984, 1988; Rawls, 1993, 1997, 2001).

Contemporary cognitive research supports the notion that our value beliefs are closely linked to our scientific beliefs. A striking example can be found in the research of Lewandowsky et al., which indicates that strong belief in the value of free market economies serves to predict the likelihood of climate science rejection. Similarly of relevance, it is also found to be the case, to a lesser but still significant degree, that belief in conspiracy theories predicts the rejection of climate science (Lewandowsky, Gignac, & Oberauer, 2013b). It should be noticed that conspiratorial accusations aimed at mainstream science are common among both pseudoskeptics of evolution and climate change. Indeed, there is evidence suggestive that conspiratorial claims are positively correlated with pseudoscientific beliefs (as well as paranormal beliefs more generally) (Lobato, Mendoza, Sims, & Chin, 2014).

A connection between pseudoscience and conspiracy theory is not surprising. Those engaging in pseudoscience often invoke conspiratorial claims to explain why their views are not taken more seriously by mainstream scientists. Such views are consistent with holistic background beliefs, held by proponents of pseudoscience, that their theories are correct and that their epistemic standards are scientific. An important aspect of conspiratorial thinking is that it is self-sealing in nature. This means that attempts to refute conspiracy claims are commonly incorporated into the conspiracy (Lewandowsky, Gignac, & Oberauer, 2013b). The self-sealing nature of conspiracy theories ensures that no evidence given against a conspiracy theory need be taken seriously by the conspiracy theorist. Importantly, links between epistemically strong beliefs also occur.

Researchers have recently gathered evidence for what has been called the “gateway belief model.” The gateway belief model has been used to explain why belief in the scientific consensus on anthropogenic climate change is found to causally correlate with increased belief in the reality of climate change (Cook & Lewandowsky, 2016; van der Linden, Leiserowitz, Feinberg, & Maibach, 2015). Such findings are consistent with other research on the persuasiveness of “consensus messaging” (discussed below in Section 'Public reason and the importance of referencing scientific consensus in public discourse') (Lewandowsky, Gignac, & Vaughan, 2013c; Maibach, Leiserowitz, & Gould, 2013; Maibach, Myers, & Leiserowitz, 2014). These findings suggest the existence of beliefs, or cognitive patterns, that reflect particular cognitive styles, which serve to encourage or discourage particular types of belief (Lewandowsky, Gignac, & Oberauer, 2013b). Such cognitive styles are consistent with Clifford's moral concern that any given belief will contribute to cognitive conditions for related beliefs to follow.

3.3 Clifford's second premise and social influence

The beliefs that we hold influence the groups with whom we identify, and the groups with whom we identify in turn reinforce and influence the beliefs and values we hold. When we believe that something will benefit “our” group, we have a greater tendency to engage in motivated reasoning to support that belief. This phenomenon is well recognized, beyond Clifford, by moral and political philosophers who must confront the reality of group polarizations while seeking workable approaches to moral and political problems (Berlin, 1990; Engelhardt, 1996; Habermas, 1985; Kitcher 2003; Rawls, 1993, 1997; Singer, 2011; Talisse, 2009, 2011; Torcello, 2011).

Again, cognitive research confirms that political and economic ideologies predict the acceptance or rejection of our beliefs about climate science (Kahan, Jenkins-Smith, & Braman, 2011; Kahan et al., 2012; Lewandowsky, Gignac, & Vaughan, 2013c; McCright, 2011; McCright & Dunlap, 2011a,b; Painter, 2011). Such influence speaks to the impact of others with whom we identify and are affiliated culturally (Sweetman & Whitmarsh, 2016). The correspondence between cultural identification and a person's acceptance of climate science has been documented by Kahan and others, who label the impact of cultural identity on our formation and acceptance of beliefs as the effect of “cultural cognition” (Kahan et al., 2011, 2012). According to this research, individuals will gravitate to beliefs, and interpret information, in ways that serve to protect the values they associate with their cultural sense of self. Once we have established our sense of cultural identity, it is difficult to revise beliefs strongly associated with that identity. Indeed, this problem is supported by research conducted by Shtulman and Valcarcel showing that our previous beliefs continue to influence our understanding of science even after updated information is received (Shtulman, 2006; Shtulman & Valcarcel, 2012; Shtulman, 2016).

These findings are consistent with my formulation of Clifford's second premise (P₂) that our beliefs (including ideological and value beliefs) exert a social influence in ways that are not easily predictable. The driving assumption here is that given our social nature, our reliance on community life, and our tendency toward group identifications, our beliefs are bound to be socially impactful. Indeed, our examination of the first premise (P₁) and of the role that group affiliation plays in affecting our cognitive styles provides further support for the social nature of our beliefs taken up in the second premise. It is, therefore, morally hazardous to hold epistemically unwarranted beliefs (including value, metaphysical, or religious beliefs, which stand outside the realm of empirical support). The ethics of belief (and its implications for inquiry), especially in the context of the research cited above, suggests a level of increased epistemic and ethical responsibility, especially for those with greater access to the public sphere and influence over their fellow citizens.

4.1 Evaluating experts

It is thus necessary that one be able to recognize appropriate expertise in science when such expertise exists. The philosopher Alvin Goldman has examined some of the criteria of use to non-experts in their efforts to discern appropriate scientific expertise. The first criterion introduced by Goldman involves straightforwardly assessing the quality of arguments presented by the alleged expert (Goldman, 2001). This, as philosopher Massimo Pigliucci points out, is sometimes possible for an intelligent and informed layperson to assess, but it becomes increasingly difficult as information becomes more technical (Pigliucci, 2010). For this reason, it is important to look for agreement among other experts in the field (Goldman, 2001; Pigliucci, 2010).

This requires that one pay attention to the credentials an alleged expert has, and evidence that they are performing their role as experts in as unbiased a fashion as possible. In addition, researchers who have achieved a strong record of accomplishment in their field, as judged by their peers, deserve to have their opinions weighted more heavily than less accomplished experts (Goldman, 2001; Pigliucci, 2010). There is reason to be cautious if a given expert is employed by a corporation that benefits from that expert's promotion of evidence conducive to the latter's corporate agenda (Pigliucci, 2010). An obvious example is if a scientist, with legitimate expertise, is positing contrarian views regarding anthropogenic climate change while being paid by an oil company for consultation work. Another example is if a scientist receives private funding from corporate entities with an obvious stake in particular findings.17 This is why it is crucial for scientists to make such conflicts of interest known and it is a serious ethical concern when conflicts of interest are not declared.18 The possibility always exists that individual experts can be wrong or inappropriately influenced. It is all the more important for the layperson to defer to the consensus opinion of experts, when available, since a community of experts is less vulnerable in the aggregate to inappropriate influence than any one individual.

None of this is epistemically perfect and all of it requires some initial ability to identify relevant matters (like the existence of relevant educational credentials). Despite the legitimate challenges poised for the layperson in assessing expertise, there are some cases where determining expertise is relatively straightforward. In cases like anthropogenic climate change, the existence of an Intergovernmental Panel on Climate Change (IPCC), organized independently of any one group's agenda, and tasked with sorting through the global body of research related to climate change, makes it easier for the lay person to know where to turn for good information. IPCC reports are widely publicized and available online for easy access to policy makers and the general public.

4.2 Trusting scientific consensus

It bears emphasizing again why trusting in scientific consensus is important for non-experts wishing to engage responsibly with scientific findings. As the philosopher Bertrand Russell explains:

There are matters about which those who have investigated them are agreed; the dates of eclipses may serve as an illustration. There are other matters about which experts are not agreed. Even when the experts all agree, they may well be mistaken. Einstein's view as to the magnitude of the deflection of light by gravitation would have been rejected by all experts not many years ago, yet it proved to be right. Nevertheless the opinion of experts, when it is unanimous, must be accepted by non-experts as more likely to be right than the opposite opinion. The scepticism that I advocate amounts only to this: (a) that when the experts are agreed, the opposite opinion cannot be held to be certain; (b) that when they are not agreed, no opinion can be regarded as certain by a non-expert; and (c) that when they all hold that no sufficient grounds for a positive opinion exist, the ordinary man would do well to suspend his judgment. These propositions may seem mild, yet, if accepted, they would absolutely revolutionize human life. (1928)

Though Russell uses the word unanimous in this passage, we can reliably assume, consistent with the rest of the quote, that he actually means consensus. Assuming Einstein to be an expert who was not in agreement with other experts reflects the reality of consensus, but not unanimity (Torcello, 2011).

4.3 Public reason and the importance of referencing scientific consensus in public discourse

The ethical and political significance of referencing a scientific consensus when relevant to ongoing public discussions (such as policy discussions regarding anthropogenic climate change) supports the crucial role of public reason in political discourse. Public reason is a concept emphasized by the political philosopher John Rawls as a discursive framework to help guide constructive debate in highly diverse and pluralistic modern societies. The impetus for emphasizing public reason is the recognition that a plurality of comprehensive doctrines exist within free societies. A comprehensive doctrine is one that purports to explain the world in a detailed way involving both epistemic and ethical values. It may be a religious doctrine or a secular philosophical doctrine. In many cases members of differing comprehensive doctrines come into conflict over basic issues of justice and the essential features of democratic governance.

In working out these differences the ideal of public reason requires that arguments be made in a way understandable to reasonable members of distinct comprehensive doctrines even if they disagree. For instance, in public-sphere political discussions about contentious topics like abortion, reasonable citizens should avoid making metaphysical and religiously laden claims and instead appeal to arguments independent of such contentious content. Likewise, if established science exists, citizens ought to agree to reference such science, even when in disagreement with that science. In this way a fair and civil discourse can be procedurally maintained to determine the best democratic policy decisions (Rawls, 1993, 1997, 2001). Placing an emphasis on public reason helps to address Clifford's ethical concerns regarding inquiry and belief since it requires us to reference scientifically vetted facts in public discourse when such facts are available. It turns out that public reason’s emphasis on settled science in public discourse can also be part of an effective strategy for climate communication consistent with empirical findings.

There is a great deal of evidence that repeatedly highlighting in particular the scientific consensus on climate change can serve to neutralize cognitive resistance to climate science (Cook & Jacobs, 2014; Cook & Lewandowsky, 2016; Kotcher, Myers, Maibach, & Leiserowitz, 2014; Lewandowsky, Gignac, & Vaughan, 2013c; Maibach, Leiserowitz, & Gould, 2013; McCright, Dunlap, & Xiao, 2013). It is important to think clearly about what these findings mean. It is not enough that the research referenced in this paper offers support to Clifford's concerns regarding the ethics of belief, or Rawls' concerns regarding public discourse. If cognitive research is to inform our normative approach to science communication, on publicly contentious topics like climate change, it must be the case that different research findings ultimately lead us to consistent recommendations.

5.1 Familiarity and exposure in belief formation

The more familiar we become with a set of beliefs, the more open we are to the acceptance of those beliefs. Marketers and political operatives know this; it is also the operative reason that arguments from repetition work, even if they are fallacious. As a fallacy, the argument from repetition involves the repeated utterance of a controversial claim until the audience comes to accept it, through the sheer force of familiarity. This argumentum ad nauseam is fallacious if it is offered as a substitute for evidential justification. Otherwise, clear and unequivocal repetition of a concept can be an effective tactic in communicating unfamiliar information to an audience. In psychology, the familiarity principle, sometimes referred to as the mere-exposure effect, is well documented (Bornstein, 1989; Zajonc, 1968, 1980, 2001). We are influenced more by those with whom we are familiar, and those with whom we are familiar tend to make up our social and communal spheres (Sweetman & Whitmarsh, 2016).

It bears emphasizing that the psychological effect of familiarity is consistent with studies demonstrating both the influence of cultural cognition and the importance of communicating climate consensus. Even when a group is polarized and hostile against a scientific finding, there is reason to think that consistent exposure to the fact of scientific consensus will soften resistance and may even eventually be incorporated into a group's cultural identity. Once interpreted this way, the apparent conflict between the cultural cognition model and the information deficit model disappears. What is more, repeated exposure to new information may be necessary to mitigate the lingering influence of prior misinformation, or misunderstanding, given the findings of Schtulman and Valcarcel (Shtulman, 2006; Shtulman & Valcarcel, 2012; Shtulman, 2016).