Climate change belief systems across political groups in the United States.

Beliefs and attitudes form the core of public opinion about climate change. Network analysis can reveal the structural configuration of these beliefs and attitudes. In this research, we utilize a belief system framework to identify key psychological elements, track change in the density of these belief systems over time and across political groups, and analyze the structural heterogeneity of belief systems within and between political groups in the United States. Drawing on fifteen waves of nationally representative survey data from 2010 to 2021 (N = 16,742), our findings indicate that worry about climate change is the most central psychological element. Interestingly, we find that among politically unaffiliated individuals, the connections between psychological elements have strengthened over time, implying an increase in the consistency of belief systems within this group. Despite the political polarization in beliefs about climate change between Republicans and Democrats, our findings reveal that the ways these two groups organize and structure climate change beliefs systems are not markedly different compared to those of other groups. These findings provide theoretical and practical insights for climate change experts and communicators.

Limiting global warming to 1.5 to 2.0°C-A unique and necessary role for health professionals.

In an Editorial, Edward Maibach and colleagues discuss the important role of health professionals in future responses to threats of climate change.

Correction: Controversy matters: Impacts of topic and solution controversy on the perceived credibility of a scientist who advocates.

[This corrects the article DOI: 10.1371/journal.pone.0187511.].

Correction: Controversy matters: Impacts of topic and solution controversy on the perceived credibility of a scientist who advocates.

[This corrects the article DOI: 10.1371/journal.pone.0187511.].

Health Implications of Climate Change: a Review of the Literature About the Perception of the Public and Health Professionals.

PURPOSE OF REVIEW: Through a systematic search of English language peer-reviewed studies, we assess how health professionals and the public, worldwide, perceive the health implications of climate change. RECENT FINDINGS: Among health professionals, perception that climate change is harming health appears to be high, although self-assessed knowledge is low, and perceived need to learn more is high. Among the public, few North Americans can list any health impacts of climate change, or who is at risk, but appear to view climate change as harmful to health. Among vulnerable publics in Asia and Africa, awareness of increasing health harms due to specific changing climatic conditions is high. Americans across the political and climate change opinion spectra appear receptive to information about the health aspects of climate change, although findings are mixed. Health professionals feel the need to learn more, and the public appears open to learning more, about the health consequences of climate change.

Controversy matters: Impacts of topic and solution controversy on the perceived credibility of a scientist who advocates.

In this article, we focus on the potential influence of a scientist's advocacy position on the public's perceived credibility of scientists as a whole. Further, we examine how the scientist's solution position (information only, non-controversial, and controversial) affects the public's perception of the scientist's motivation for sharing information about specific issues (flu, marijuana, climate change, severe weather). Finally, we assess how perceived motivations mediate the relationship between solution position and credibility. Using data from a quota sample of American adults obtained by Qualtrics (n = 2,453), we found that in some conditions advocating for a solution positively predicted credibility, while in one condition, it negatively predicted scientist credibility. We also found that the influence of solution position on perceived credibility was mediated by several motivation perceptions; most notably through perception that the scientist was motivated to: (a) serve the public and (b) persuade the public. Further results and implications are discussed.

Survey of International Members of the American Thoracic Society on Climate Change and Health.

The American Thoracic Society (ATS), in collaboration with George Mason University, surveyed international members of the society to assess perceptions, clinical experiences, and preferred policy responses related to global climate change. A recruitment email was sent by the ATS President in October 2015 to 5,013 international members. Subsequently, four reminder emails were sent to nonrespondents. Responses were received from 489 members in 68 countries; the response rate was 9.8%. Half of respondents reported working in countries in Asia (25%) or Europe (25%), with the remainder in South America (18%), North America (Canada and Mexico) (18%), Australia or New Zealand (9%), and Africa (6%). Survey estimate confidence intervals were ± 5% or smaller. A high percentage of international ATS survey respondents judged that climate change is happening (96%), that it is driven by human activity (70%), and that it is relevant to patient care ("a great deal"/"a moderate amount") (80%). A majority of respondents also indicated they are already observing health impacts of climate change among their patients; most commonly as increases in chronic disease severity from air pollution (88%), allergic symptoms from exposure to plants or mold (72%), and severe weather injuries (69%). An even larger majority anticipated seeing these climate-related health impacts in the next two decades. Respondents further indicated that physicians and physician organizations should play an active role in educating patients, the public, and policy makers on the human health effects of climate change. International ATS respondents, like their counterparts in the U.S., observed that human health is already adversely affected by climate change, and support responses to address this situation.

Adapting to the Changing Climate: An Assessment of Local Health Department Preparations for Climate Change-Related Health Threats, 2008-2012.

BACKGROUND: Climate change poses a major public health threat. A survey of U.S. local health department directors in 2008 found widespread recognition of the threat, but limited adaptive capacity, due to perceived lack of expertise and other resources. METHODS: We assessed changes between 2008 and 2012 in local public health departments' preparedness for the public health threats of climate change, in light of increasing national polarization on the issue, and widespread funding cutbacks for public health. A geographically representative online survey of directors of local public health departments was conducted in 2011-2012 (N = 174; response rate = 50%), and compared to the 2008 telephone survey results (N = 133; response rate = 61%). RESULTS: Significant polarization had occurred: more respondents in 2012 were certain that the threat of local climate change impacts does/does not exist, and fewer were unsure. Roughly 10% said it is not a threat, compared to 1% in 2008. Adaptation capacity decreased in several areas: perceived departmental expertise in climate change risk assessment; departmental prioritization of adaptation; and the number of adaptation-related programs and services departments provided. In 2008, directors' perceptions of local impacts predicted the number of adaptation-related programs and services their departments offered, but in 2012, funding predicted programming and directors' impact perceptions did not. This suggests that budgets were constraining directors' ability to respond to local climate change-related health threats. Results also suggest that departmental expertise may mitigate funding constraints. Strategies for overcoming these obstacles to local public health departments' preparations for climate change are discussed.

Highlighting consensus among medical scientists increases public support for vaccines: evidence from a randomized experiment.

BACKGROUND: A substantial minority of American adults continue to hold influential misperceptions about childhood vaccine safety. Growing public concern and refusal to vaccinate poses a serious public health risk. Evaluations of recent pro-vaccine health communication interventions have revealed mixed results (at best). This study investigated whether highlighting consensus among medical scientists about childhood vaccine safety can lower public concern, reduce key misperceptions about the discredited autism-vaccine link and promote overall support for vaccines. METHODS: American adults (N = 206) were invited participate in an online survey experiment. Participants were randomly assigned to either a control group or to one of three treatment interventions. The treatment messages were based on expert-consensus estimates and either normatively described or prescribed the extant medical consensus: "90 % of medical scientists agree that vaccines are safe and that all parents should be required to vaccinate their children". RESULTS: Compared to the control group, the consensus-messages significantly reduced vaccine concern (M = 3.51 vs. M = 2.93, p < 0.01) and belief in the vaccine-autism-link (M = 3.07 vs M = 2.15, p < 0.01) while increasing perceived consensus about vaccine safety (M = 83.93 vs M = 89.80, p < 0.01) and public support for vaccines (M = 5.66 vs M = 6.22, p < 0.01). Mediation analysis further revealed that the public's understanding of the level of scientific agreement acts as an important "gateway" belief by promoting public attitudes and policy support for vaccines directly as well as indirectly by reducing endorsement of the discredited autism-vaccine link. CONCLUSION: These findings suggest that emphasizing the medical consensus about (childhood) vaccine safety is likely to be an effective pro-vaccine message that could help prevent current immunization rates from declining. We recommend that clinicians and public health officials highlight and communicate the high degree of medical consensus on (childhood) vaccine safety when possible.

Do Americans Understand That Global Warming Is Harmful to Human Health? Evidence From a National Survey.

BACKGROUND: Global warming has significant negative consequences for human health, with some groups at greater risk than others. The extent to which the public is aware of these risks is unclear; the limited extant research has yielded discrepant findings. OBJECTIVES: This paper describes Americans' awareness of the health effects of global warming, levels of support for government funding and action on the issue, and trust in information sources. We also investigate the discrepancy in previous research findings between assessments based on open- versus closed-ended questions. METHODS: A nationally representative survey of US adults (N = 1275) was conducted online in October 2014. Measures included general attitudes and beliefs about global warming, affective assessment of health effects, vulnerable populations and specific health conditions (open- and closed-ended), perceived risk, trust in sources, and support for government response. FINDINGS: Most respondents (61%) reported that, before taking the survey, they had given little or no thought to how global warming might affect people's health. In response to a closed-ended question, many respondents (64%) indicated global warming is harmful to health, yet in response to an open-ended question, few (27%) accurately named one or more specific type of harm. In response to a closed-ended question, 33% indicated some groups are more affected than others, yet on an open-ended question only 25% were able to identify any disproportionately affected populations. Perhaps not surprising given these findings, respondents demonstrated only limited support for a government response: less than 50% of respondents said government should be doing more to protect against health harms from global warming, and about 33% supported increased funding to public health agencies for this purpose. Respondents said their primary care physician is their most trusted source of information on this topic, followed by the Centers for Disease Control and Prevention, the World Health Organization, and their local public health department. CONCLUSIONS: Most Americans report a general sense that global warming can be harmful to health, but relatively few understand the types of harm it causes or who is most likely to be affected. Perhaps as a result, there is only moderate support for an expanded public health response. Primary care physicians and public health officials appear well positioned to educate the public about the health relevance of climate change.

The scientific consensus on climate change as a gateway belief: experimental evidence.

There is currently widespread public misunderstanding about the degree of scientific consensus on human-caused climate change, both in the US as well as internationally. Moreover, previous research has identified important associations between public perceptions of the scientific consensus, belief in climate change and support for climate policy. This paper extends this line of research by advancing and providing experimental evidence for a "gateway belief model" (GBM). Using national data (N = 1104) from a consensus-message experiment, we find that increasing public perceptions of the scientific consensus is significantly and causally associated with an increase in the belief that climate change is happening, human-caused and a worrisome threat. In turn, changes in these key beliefs are predictive of increased support for public action. In short, we find that perceived scientific agreement is an important gateway belief, ultimately influencing public responses to climate change.

American Thoracic Society member survey on climate change and health.

The American Thoracic Society (ATS), in collaboration with George Mason University, surveyed a random sample of ATS members to assess their perceptions of, clinical experiences with, and preferred policy responses to climate change. An e-mail containing an invitation from the ATS President and a link to an online survey was sent to 5,500 randomly selected U.S. members; up to four reminder e-mails were sent to nonrespondents. Responses were received from members in 49 states and the District of Columbia (n = 915); the response rate was 17%. Geographic distribution of respondents mirrored that of the sample. Survey estimates' confidence intervals were ±3.5% or smaller. Results indicate that a large majority of ATS members have concluded that climate change is happening (89%), that it is driven by human activity (68%), and that it is relevant to patient care ("a great deal"/"a moderate amount") (65%). A majority of respondents indicated they were already observing health impacts of climate change among their patients, most commonly as increases in chronic disease severity from air pollution (77%), allergic symptoms from exposure to plants or mold (58%), and severe weather injuries (57%). A larger majority anticipated seeing these climate-related health impacts in the next 2 decades. Respondents indicated that physicians and physician organizations should play an active role in educating patients, the public, and policy makers on the human health effects of climate change. Overall, ATS members are observing that human health is already adversely affected by climate change and support responses to address this situation.

A survey of African American physicians on the health effects of climate change.

The U.S. National Climate Assessment concluded that climate change is harming the health of many Americans and identified people in some communities of color as particularly vulnerable to these effects. In Spring 2014, we surveyed members of the National Medical Association, a society of African American physicians who care for a disproportionate number of African American patients, to determine whether they were seeing the health effects of climate change in their practices; the response rate was 30% (n = 284). Over 86% of respondents indicated that climate change was relevant to direct patient care, and 61% that their own patients were already being harmed by climate change moderately or a great deal. The most commonly reported health effects were injuries from severe storms, floods, and wildfires (88%), increases in severity of chronic disease due to air pollution (88%), and allergic symptoms from prolonged exposure to plants or mold (80%). The majority of survey respondents support medical training, patient and public education regarding the impact of climate change on health, and advocacy by their professional society; nearly all respondents indicated that the US should invest in significant efforts to protect people from the health effects of climate change (88%), and to reduce the potential impacts of climate change (93%). These findings suggest that African American physicians are currently seeing the health impacts of climate change among their patients, and that they support a range of responses by the medical profession, and public policy makers, to prevent further harm.

Information Seeking about Global Climate Change among Adolescents: The Role of Risk Perceptions, Efficacy Beliefs and Parental Influences.

Global climate change is likely to have significant impacts on public health. Effective communication is critical to informing public decision making and behavior to mitigate climate change. An effective method of audience segmentation, the risk perception attitude (RPA) framework has been previously tested with other health behaviors and classifies people into 4 groups on the basis of their perceptions of risk and beliefs about personal efficacy. The 4 groups - indifference (low risk, weak efficacy), proactive (low risk, strong efficacy), avoidance (high risk, weak efficacy), and responsive (high risk, strong efficacy) - are hypothesized to differ in their self-protective behaviors and in their motivations to seek information. In this paper, we extend the RPA framework in two ways. First, we use it at the household level to determine whether parental classifications into the 4 groups are associated with their teenage children's classification into the same 4 groups. Second, we predict adolescent information-seeking behaviors on the basis of their and their parents' membership in the 4 RPA groups. Results (N = 523 parent-adolescent pairs) indicated that parental membership in the 4 RPA groups was significantly associated with children's membership in the same 4 groups. Furthermore, the RPA framework was a significant predictor of adolescent information-seeking: those in the responsive and avoidance groups sought more information on climate change than the indifference group. Family communication on global warming was positively associated with adolescents' information-seeking. Implications for interventions are discussed.

Identifying like-minded audiences for global warming public engagement campaigns: an audience segmentation analysis and tool development.

BACKGROUND: Achieving national reductions in greenhouse gas emissions will require public support for climate and energy policies and changes in population behaviors. Audience segmentation--a process of identifying coherent groups within a population--can be used to improve the effectiveness of public engagement campaigns. METHODOLOGY/PRINCIPAL FINDINGS: In Fall 2008, we conducted a nationally representative survey of American adults (n = 2,164) to identify audience segments for global warming public engagement campaigns. By subjecting multiple measures of global warming beliefs, behaviors, policy preferences, and issue engagement to latent class analysis, we identified six distinct segments ranging in size from 7 to 33% of the population. These six segments formed a continuum, from a segment of people who were highly worried, involved and supportive of policy responses (18%), to a segment of people who were completely unconcerned and strongly opposed to policy responses (7%). Three of the segments (totaling 70%) were to varying degrees concerned about global warming and supportive of policy responses, two (totaling 18%) were unsupportive, and one was largely disengaged (12%), having paid little attention to the issue. Certain behaviors and policy preferences varied greatly across these audiences, while others did not. Using discriminant analysis, we subsequently developed 36-item and 15-item instruments that can be used to categorize respondents with 91% and 84% accuracy, respectively. CONCLUSIONS/SIGNIFICANCE: In late 2008, Americans supported a broad range of policies and personal actions to reduce global warming, although there was wide variation among the six identified audiences. To enhance the impact of campaigns, government agencies, non-profit organizations, and businesses seeking to engage the public can selectively target one or more of these audiences rather than address an undifferentiated general population. Our screening instruments are available to assist in that process.

Public perceptions of climate change as a human health risk: surveys of the United States, Canada and Malta.

We used data from nationally representative surveys conducted in the United States, Canada and Malta between 2008 and 2009 to answer three questions: Does the public believe that climate change poses human health risks, and if so, are they seen as current or future risks? Whose health does the public think will be harmed? In what specific ways does the public believe climate change will harm human health? When asked directly about the potential impacts of climate change on health and well-being, a majority of people in all three nations said that it poses significant risks; moreover, about one third of Americans, one half of Canadians, and two-thirds of Maltese said that people are already being harmed. About a third or more of people in the United States and Canada saw themselves (United States, 32%; Canada, 67%), their family (United States, 35%; Canada, 46%), and people in their community (United States, 39%; Canada, 76%) as being vulnerable to at least moderate harm from climate change. About one third of Maltese (31%) said they were most concerned about the risk to themselves and their families. Many Canadians said that the elderly (45%) and children (33%) are at heightened risk of harm, while Americans were more likely to see people in developing countries as being at risk than people in their own nation. When prompted, large numbers of Canadians and Maltese said that climate change can cause respiratory problems (78-91%), heat-related problems (75-84%), cancer (61-90%), and infectious diseases (49-62%). Canadians also named sunburn (79%) and injuries from extreme weather events (73%), and Maltese cited allergies (84%). However, climate change appears to lack salience as a health issue in all three countries: relatively few people answered open-ended questions in a manner that indicated clear top-of-mind associations between climate change and human health risks. We recommend mounting public health communication initiatives that increase the salience of the human health consequences associated with climate change.