Reframing climate change as a public health issue: an exploratory study of public reactions
Climate change is taking a toll on human health, and some leaders into the public health community have urged their colleagues to give voice to its health implications. Previous research has shown that Americans are only dimly aware of the health implications of climate change, yet the literature on issue framing suggests that providing a novel frame – such as human health – might be potentially useful in enhancing public engagement. We conducted an exploratory study in the United States of people’s reactions to a public health-framed short essay on climate change.
U.S. adult respondents (n = 70), stratified by six previously identified audience segments, read the essay and were asked to highlight in green or pink any portions of the essay they found “especially clear and helpful” or alternatively “especially confusing or unhelpful.” Two dependent measures were created: a composite sentence-specific score based on reactions to all or any 18 sentences into the essay; and respondents’ general reactions towards the essay that were coded for valence (positive, neutral, or negative). We tested the hypothesis that five of the six audience segments would respond positively towards the essay on both dependent measures.
There was clearly clear evidence that two of the five segments responded positively towards the public health essay, and mixed evidence that two other responded positively. There was clearly limited evidence that the fifth segment responded positively. Post-hoc analysis showed that five of the six segments responded more positively to information regarding the health benefits associated with mitigation-related policy actions than to information regarding the health risks of climate change.
Presentations about climate change that encourage people to consider its human health relevance appear expected to provide many Americans with a useful and engaging new frame of reference. Information regarding the potential health benefits of specific mitigation-related policy actions appears to be particularly compelling. We believe that the public health community has an important perspective to fairly share about climate change, a perspective that makes the situation more personally relevant, significant, and understandable to members of the public.
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Climate change is already taking a toll on human health into the United States  and other nations worldwide . Unless greenhouse gas emissions worldwide are sharply curtailed – and significant actions taken to help communities adapt to changes in their climate that are unavoidable – the human toll of climate change is likely to become dramatically worse within the next several decades and beyond . Globally, the human health impacts of climate change will continue to differentially affect the world’s poorest nations, where populations endemically suffer myriad health burdens associated with extreme poverty that are being exacerbated by the changing climate. As stated in a recent British Medical Journal editorial, failure of the world’s nations to successfully curtail emissions will likely lead to a “global health catastrophe” . In developed countries such as the United States, the segments of the population most at risk are the poor, the very young, the elderly, those already in poor health, the disabled, individuals living alone, those with inadequate housing or basic services, and/or individuals who lack access to affordable health care or who live in areas with weak public health systems. These population segments disproportionately include racial, ethnic, and indigenous minorities .
While legislation to reduce U.S. greenhouse gas (GHG) emissions has stalled in Congress, in December 2009 the Environmental Protection Agency (EPA) moved toward regulating carbon dioxide and five other of the gases under the Clean Air Act, citing its authority to protect public health and welfare from the impacts of global warming . The agency found that global warming poses public health risks – including increased morbidity and mortality – due to declining air quality, rising temperatures, increased frequency of extreme weather events, and higher incidences of food- and water-borne pathogens and allergens.
This finding comes as a relatively small selection of public health professionals are working rapidly to better comprehend and quantify the nature and magnitude of those threats to human health and wellbeing . This new but rapidly advancing public health focus has received minimal news media attention, even at internationally leading news organizations including the New York Times [unpublished data]. It’s not surprising therefore that the public comes with yet to fully comprehend the public health implications of climate change. Recent surveys of Americans , Canadians , and Maltese  demonstrate that the human health consequences of climate change are seriously underestimated and/or poorly understood, if grasped at all. About half of American survey respondents, for example, selected “don’t know” (rather than “none,” “hundreds,” “thousands,” or “millions”) when asked the estimated number of current and future (i.e. 50 years hence) injuries and illnesses, and death due to climate change. An earlier survey of Americans  demonstrated that most people see climate change as a geographically and temporally distant threat towards the non-human environment. Notably, not a single survey respondent freely associated climate change as representing a threat to people. Similarly, few Canadians, without prompting, can name any specific human health threat linked to climate change impacts in their country .
Cognitive research over the past several decades has shown that how people “frame” an issue – i.e., how they mentally organize and discuss with others the issue’s central ideas – greatly influences how they understand the nature of the problem, who or what they see as being responsible for the situation, and what they feel should be done to address the problem [11, 12]. The polling data cited above [7–9] suggests that the dominant mental frame used by most members of the public to organize their conceptions about climate change is that of “climate change as an environmental problem.” However, when climate change is framed as an environmental problem, this interpretation likely distances many people from the issue and contributes to a lack of serious and sustained public engagement necessary to develop solutions. This focus is also vunerable to a dominant counter frame that the best solution is to continue to grow the economy – paying for adaptive measures as time goes by when, theoretically, society may be wealthier and better able to afford them – rather than focus on the root factors behind the environmental problem . This economic frame likely leaves the public ambivalent about policy action and works to the advantage of industries that are reluctant to reduce their carbon intensity. Indeed, it is precisely the lack of a countervailing populist movement on climate change that includes made policy solutions so difficult to enact [13, 14].
Significant efforts have been made over the past several years by public health organizations to improve awareness of the public health implications of climate change and prepare the public health workforce to respond, although as noted above, it’s not clear the extent to which public health professionals, journalists, or most of all, the public and policy makers have taken notice. In the United States, National Public Health Week 2008 was themed “Climate Change: Our Health in the Balance,” the Centers for Disease Control and Prevention created a Climate Change and Public Health program, and several professional associations assessed the public health system’s readiness to respond to the emerging threat [15–17]. Globally, World Health Day 2008 was themed “Protecting Health from Climate Change,” and the World Health Organization is rolling out a climate change and health work plan, the first objective of which is “raising awareness of the effects of climate change on health, in order to prompt action for public health measures” . Several prominent medical journals have released special issues on climate change and health [19–21], and these and other medical journals  have issued strongly worded editorials urging health professionals to give voice towards the health implications of climate change.
An important assumption in these calls to action is that there may be considerable value in introducing a public health frame into the ongoing public – and policy – dialogue about climate change. While there is indeed solid theoretical basis for this assumption, towards the best of our knowledge there is not yet empirical evidence to support the validity of the assumption .
The purpose of this study therefore was to explore how American adults respond to an essay about climate change framed as a public health issue. Our hypothesis was that a public health-framed explanation of climate change would be perceived as useful and personally relevant by readers, with the exception of members of one small segment of Americans who dismiss the notion that human-induced climate change is happening. We used two dependent measures in this hypothesis: a composite score based on respondent reactions to each sentence into the essay, plus the overall valence of respondents’ general comments made after reading the essay.
Our study builds on previous research that identified six distinct segments of Americans, termed Global Warming’s Six Americas . These six segments of Americans – the Alarmed (18% of the adult population), the Concerned (33%), the Cautious (19%), the Disengaged (12%), the Doubtful (11%), plus the Dismissive (7%) – fall along a continuum from those who are engaged regarding the issue and looking for techniques to take appropriate actions (the Alarmed) to those who actively deny its reality and are also researching to oppose societal action (the Dismissive; see Figure 1). The four segments in the middle of the continuum will probably benefit most from a reframing of climate change as a human health problem because, to a better or lesser degree, they are not yet sure that they fully understand the issue and are also still, if motivated to do so, relatively open to learning about new perspectives.
Global Warming’s Six Americas. A nationally representative sample of American adults classified into six unique audience segments centered on their climate change-related beliefs, behaviors and policy preferences.
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Between May and August 2009, 74 adults were recruited to participate in semi-structured in-depth elicitation interviews that lasted an average of 43 minutes (ranging from 16 to 124 minutes) and included the presentation of a public health framed essay on climate change. The recruitment process was designed to yield completed interviews with a demographically and geographically diverse selection of at least 10 people from each of the previously identified “Six Americas” . Four respondents were dropped using this study due to incomplete data, leaving a sample size of 70. Audience segment status (i.e., which one of many “Six Americas” a person belonged) was assessed with a previously developed 15-item screening questionnaire that identifies segment status with 80% accuracy [unpublished data].
To reach demographic diversity in the sample, we recruited an approximately balanced quantity of gents and ladies, and an approximately balanced quantity of younger (18 to 30), middle-aged (31 to 50), and older (51 and older) adults (see Table 1). We did not set recruitment quotas for racial/ethnic groups, but did make an effort to recruit a mix of people from various racial/ethnic backgrounds.
Table 1 Distribution of Respondents by Age, Gender and Segment.
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To reach geographic diversity, we recruited participants in one of two ways. The majority of participants (n = 56) were recruited – and then interviewed – face-to-face in one of two locations: out-of-town visitors were interviewed at a central location on the National Mall in Washington, DC (a national park situated involving the U.S. Capitol, the Smithsonian Museum buildings, plus the Lincoln Memorial); and shoppers were interviewed at an “outlet” mall (i.e., discount branded merchandise shopping mall) adjacent to an interstate freeway in Hagerstown, MD. The outlet mall is more than an hour driving distance outside of Washington, DC and attracts shoppers from Maryland, Pennsylvania, and West Virginia, as well as visitors from further away who are driving the interstate freeway. The remaining study participants were recruited via email from among participants to a nationally representative survey that we conducted in Fall 2008 . These people were interviewed subsequently by telephone, after being mailed a copy of the test “public health essay” – described below – in a sealed envelope marked “do not open until asked to do so by the interviewer.” As a reason to participate, all respondents were given a $50 gift card upon completion of their interview. George Mason University Human Subjects Review Board provided approval for the study protocol (reference #6161); all potential respondents received written consent information prior to participation.
The 70 study participants resided in 29 states. Using U.S. Census Bureau classifications, 14% (n = 10) were from the Northeast region, 21% (n = 15) were from the Midwest, 40% (n = 28) from the South, and 23% (n = 16) were from the West; state and region were unknown for starters participant. In 2006, the geographic distribution of the overall U.S. population was 18%, 22%, 36% and 23% into the Northeast, Midwest, South and West, respectively .
Data Collection and Coding
The majority of the interview was devoted to open-ended questions intended to establish the respondent’s emotions, attitudes, beliefs, knowledge and behavior relative to global warming’s causes and consequences. For example, respective open-ended questions asked alternatively if, how, and for whom global warming was a problem; how global warming is caused; if and how global warming can be stopped or limited; and what, if anything, an individual could do to help limit global warming. Toward the end of the interview, respondents were asked to learn “a brief essay about global warming” (see Appendix 1), which was designed to frame climate change as a human health issue. Respondents were also given a green and a pink highlighting pen and asked to “use the green highlighter pen to mark any portions of the essay that you feel are especially clear or helpful, and use the pink highlighter pen to mark any portions of the essay that are particularly confusing or unhelpful.”
As shown in Appendix 1, usually the one page essay was organized into four sections: an opening paragraph that introduced the public health frame (5 total sentences); a paragraph that emphasized how human health may be harmed if action is not taken to stop, limit, and/or protect against global warming (i.e., a description of the threat; 7 sentences); a paragraph that discussed several mitigation-focused policy actions and their human health-related benefits if adopted (4 sentences); and a brief concluding paragraph intended to reinforce the public health frame (2 sentences).
When respondents finished the reading, these people were asked to describe in an open-ended format their “general reaction to this essay.” (Note: This question was inadvertently not asked of one respondent, therefore the sample size for analysis with this data is 69.) For each portion of the essay they marked in green, these people were subsequently asked: “What about each one of these sentences was especially clear or helpful for your requirements?” For each portion of the essay they marked in pink, these people were also asked: “What about each one of these sentences was especially confusing or unhelpful for your requirements?”
To gauge the respondent’s general reactions towards the essay we reviewed their individual statements (n = 193), defined as discrete thoughts or concepts. Centered on this review, we iteratively developed eight thematic categories that captured the range of statements made by respondents. Table 2 defines and describe these themes.
Table 2 Thematic Categories Used to Code Respondents’ General Reactions to the Public Health Essay.
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Two graduate student coders were then trained to code each statement into one of many thematic categories. The coders were also instructed to assess the overall valence of each respondent’s statements – the first of our dependent measures – rating them as: -1 (entirely negative comments); 0 (mixed, including both positive and negative comments); or 1 (entirely positive comments). Following standard content analysis procedures, we tested inter-coder agreement on approximately 50 statements, making sure that a full number of possible types of coding decisions were required of the coders. To assess reliability, we used Krippendorff’s alpha [24, 25], a conservative measure that corrects for chance agreement among coders; a K-alpha of .70 or higher is known as sufficient and .80 or higher is known as excellent. For 7 of the 8 thematic categories, we achieved a reliability of .80 or higher; “Lack of Evidence or Stylistically Confusing” was the exception, with an inter-coder reliability of .70. After establishing reliability, the two coders then went on to categorize the rest of the remaining statements from the sample of respondents.
To code the respondent’s sentence-specific reactions made out of the highlighting pens, sentences marked with only green on at least one word were scored +1 (i.e. indicating “especially clear or useful”), sentences marked with only pink on at least one word were scored -1 (i.e. indicating “especially confusing or unhelpful), and sentences with either no highlighting, or both green and pink, were scored 0. Composite scores were created for each of the four sections of the essay – the opening, the threat section, the benefit section, plus the conclusion – by summing the sentence-specific scores into the section and dividing by the quantity of sentences. A composite score for the entire essay – the second of the dependent measures in our hypothesis – was created by summing the sentence scores across each segment and dividing by the quantity of respondents per segment. Population estimates, and this can be taken solely as preliminary indicators given the non-probabilistic nature of our sampling, were estimated by weighting the mean values for each of the six segments in accordance with its prevalence into the U.S. population (see Figure 1).
To test the between-segment differences in our dependent measures – overall reactions towards the essay (i.e., valence) and composite sentence-specific reactions towards the entire essay – we used the nonparametric Kruskal-Wallis test (see Figures 2, 3). To check if the median response to the essay on each dependent measure was greater than zero (i.e., a positive reaction) for our full sample, we used the Wilcoxon signed rank test. Lastly, for both dependent measures, we used the Wilcoxon signed rank test to check our hypothesis that five of the six segments (the Dismissive being usually the one exception) would respond positively towards the essay; the essay on causes and effects of global warming for students null hypothesis was that the median score for each of the five segments did not differ from zero. The Wilcoxon signed rank test is appropriate for small sample sizes and non-normal distributions, both of which are the scenario for at least some segments in our data.
Average valence of respondents’ general essay comments. The mean valence of respondent comments when asked their general reactions towards the public health essay by audience segment and by a national population estimate. Note: 1 = (entirely positive comments); 0 = (mixed, including both positive and negative comments); and -1 = (entirely negative comments).
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Composite essay scores by segment. Scores reflect respondent average values by segment for the difference between how many times each of 18 sentences were marked “especially clear or helpful” and “especially confusing or unhelpful” with a full number of possible values between 18 and -18. The scores are adjusted for unequal numbers of respondents within each segment by re-weighting values to represent n = 10.
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Post-hoc – after examining the visualized data (see Figures 4, 5 and 6) – we decided to test for two possible main effects into the data. To examine the possibility that the essay’s later focus on the public health benefits of mitigation-related policy actions was seen by respondents as clearer and more useful compared to the essay’s earlier focus on public health-related threats, we calculated the difference between the re-scaled (by a factor of 10) average response to both the benefit together with threat sections and then used the Wilcoxon signed rank test to check, by segment, whether or not the median of those differences was greater than zero. We then evaluated the overall main effect of the essay – across all segments – making use of the weighted t-test on the differences with weights corresponding towards the frequencies of the segments into the population.
Essay evaluations by sentence: Alarmed, Concerned and Cautious segments. Sentence-specific evaluations of this public health essay by respondents in the Alarmed, Concerned and Cautious segments and by a national population estimate. Note: Scores reflect the difference between the quantity of times a sentence was marked as “especially clear or helpful” plus the quantity of times it was marked as “especially confusing or unhelpful,” adjusting for unequal numbers of respondents within each segment by re-weighting values to represent n = 10. Sentence abbreviations correspond to O = opening section (5 sentences); T = climate change health threat related section (7 sentences); B = mitigation-related policy actions and their health benefits (4 sentences); and C = concluding section (2 sentences). The national population estimate was created by weighting the values for each of the six segments in accordance with their relative proportion of American adults.
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Essay evaluations by sentence: Disengaged, Doubtful and Dismissive segments. Sentence-specific evaluations of this public health essay by respondents into the Disengaged, Doubtful and Dismissive as you like it act 1 scene 2 summary segments and by a national population estimate. Note: Scores reflect the difference between the quantity of times within a sentence was marked as “especially clear or helpful” plus the quantity of times it was marked as “especially confusing or unhelpful,” adjusting for unequal numbers of respondents within each segment by re-weighting values to represent n = 10. Sentence abbreviations correspond to O = opening section (5 sentences); T = climate change health threat related section (7 sentences); B = mitigation-related policy actions and their health benefits (4 sentences); and C = concluding section (2 sentences). The national population estimate was created by weighting the values for each of the six segments in accordance with their relative proportion of American adults.
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Essay evaluations by section (opening, threat, benefits, closing). Average section-specific evaluations of the public health essay by respondents in each of the six audience segments and by a national population estimate. Note: Scores reflect the difference between the quantity of sentences within each section marked by a respondent as “especially clear or helpful” and those marked as “especially confusing or unhelpful” with those values averaged across the quantity of sentences per section and rescaled by a factor of 10. Section abbreviations correspond to O = opening section (5 sentences); T = climate change health threat related section (7 sentences); B = mitigation-related policy actions and their health benefits (4 sentences); and C = concluding section (2 sentences). The national population estimate was created by weighting the mean values for each of the six segments in accordance with their relative proportion of American adults.
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Lastly, to examine for the possibility that the concluding framing section of the essay was perceived by respondents as clearer and more useful than the opening framing section, we calculated the difference between the re-scaled average response to both the opening and the concluding sections and then used the Wilcoxon signed rank test to check, by segment, whether or not the median of those differences was greater than zero. We then evaluated the overall main effect – across all segments – making use of the weighted t-test regarding the differences with weights corresponding towards the frequencies of the segments into the population.