SUPPLEMENTARY INFORMATION

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1 SUPPLEMENTARY INFORMATION DOI: /NCLIMATE1532 Promoting pro-environmental action in climate change deniers Bain, Hornsey, Bongiorno & Jeffries Supplementary Information Part 1 - Measures Future projections (Study 1) (Interpersonal Warmth, Competence, Morality) If Australians were to take widespread action on climate change from today, please rate how typical the following characteristics would be of Australian people in 2050, compared to Australians today. (Societal Dysfunction, Societal Development) If Australians were to take widespread action on climate change from today, please rate how this would change broad aspects of Australian society in 2050, compared to Australian society today. Environmental citizenship (Studies 1 & 2) Environmental citizenship is a sub-class of pro-environmental behaviors intended to influence public policy 1, focusing on behaviors that are more likely to be exhibited across the broad community in comparison to direct activism (e.g., participating in protests). The scale was based on an existing environmental citizenship measure which assessed past behaviors 2, adapted to focus on behavioral intentions. The exact phrasing used in the studies was: NATURE CLIMATE CHANGE 1

2 Study 1: How likely are you to engage in the following activities in the next twelve months? Study 2: Many individuals and groups interested in protecting the environment believe addressing climate change is a key concern. With this in mind, how likely are you to engage in the following activities in the next twelve months? (followed by a vertically arranged list, randomly ordered for each participant) Sign a petition in support of protecting the environment?; Join or renew membership of an environmental group?; Read a newsletter, magazine or other publication written by an environmental group?; Write a letter or call your member of Parliament or another government official to support environmental protection?; Write to a newspaper in support of protecting the environment?; If a local, state or Federal election was called, vote for a candidate at least in part because he or she was in favor of strong environmental protection? Give money to an environmental group?; Experimental conditions (Study 2) Real: It can be confusing with all the science that comes out about climate change. People like Al Gore say that reducing carbon emissions will stop the planet heating up, and most scientists seem to think that. I think that because there is general consensus among scientists we have to accept that climate change is real. I've been thinking about the impact of taking action on climate change, and I think the effects on the environment will be obvious - it follows from the science. We'd stop sea levels S2

3 rising, reduce the chance of extreme weather like droughts and floods, and save plant and animal species. We'd be less affected by food and water shortages, heat waves, flooding, and health issues that come with high temperatures. Reducing carbon emissions would certainly reduce these risks from climate change, and that would be a good pay-off. Warmth: It can be confusing with all the science that comes out about climate change. People like Al Gore say that reducing carbon emissions will stop the planet heating up, and most scientists seem to think that. But then there s other scientists who think that s not true. It got me thinking about what the world would be like if everyone pulled together to reduce carbon emissions. It might stop climate change who knows? But I think one thing it would do for sure is affect who we are as people. People focus on the environmental effects of action on climate change, but that's not how I see it. I think about how taking action would impact the community, and on balance I think it would be good. Taking action to reduce energy pollution would help us become more aware of how we live and how we impact on each other. I think it d make us more considerate in other ways like looking out for each other, and caring for people in the community. Who knows what it would do for the climate, but I think it d make for a community where people are less selfish and more considerate in the long-run, and that would be a good pay-off. Development: It can be confusing with all the science that comes out about climate change. People like Al Gore say that reducing carbon emissions will stop the planet heating up, and most scientists seem to think that. But then there s other scientists who think that s not true. It got me thinking about S3

4 what the world would be like if everyone pulled together to reduce carbon emissions. It might stop climate change who knows? But I think one thing it would do for sure is affect the society we live in. People focus on the environmental effects of action on climate change, but that's not how I see it. I think about how taking action would impact the community, and on balance I think it would be good. Taking action to reduce energy pollution would lead to new scientific breakthroughs and new industries, leading to new jobs and more sustainable economic development. Who knows what it would do for the climate, but I think it d make for a more prosperous and successful community in the long-run, and that would be a good pay-off. S4

5 Part 2 - Sample exclusions, demographics, and supplementary analyses Study 1. Screening questions comparing deniers with believers in anthropogenic climate change showed that deniers were more likely to be male (43% of the total sample of males, 32% of females), and were significantly older (M deniers = 50.1 years, SD = 18.2 v M believers = 41.3 years, SD = 18.4), t(473) = 5.0, p <.001. Sixty-two percent of deniers intended to vote for conservative political parties, 25% for progressive parties, 2% for independents, and 11% were uncommitted. These findings are consistent with larger national polls 3, indicating representativeness of the sample, and are similar to the US demographic profile of deniers. 4 The mean rating of environmental citizenship was 2.07 (SD = 0.93). As societal development/dysfunction items were developed for this study, a principal components analysis with varimax rotation identified underlying dimensions of responses, and the expected dimensions were identified. Additional regressions were performed to determine if relationships interacted with participant gender, type of denial (no climate change v. climate change not anthropogenic), or political affiliation (conservative v. progressive). As no interactions were significant, results from the total sample are reported. Study 2. This sample was accessed through a commercial provider, who obtained a sample from the general public across all Australian states, reflecting each state s proportion of the total population. This generated a total sample of 377. Nine participants (2%) were excluded for exhibiting convergent evidence of pattern and nonsense responding, e.g., completing the whole survey in less than 3 minutes with no variation in scores, and answering the text question with nonsensical responses like nanananananananana. We were particularly concerned about the S5

6 need for participants to have the manipulation salient in their minds when making ratings, and gave prominent instructions to complete the survey in a single sitting. However, the time taken by some participants (up to 24 hours) indicated that some ignored this direction. Excluding the time taken reading the vignette and writing the text response (which was expected to legitimately vary widely across participants), 21 participants (6%) were identified as outliers in the time taken to complete the survey (more than 45 minutes), and were also excluded. This resulted in a final sample of 347 participants, with proportional representation from each state (maximum 6% margin of error in each state when compared to official statistics). The age of Deniers (M = 50.1, SD = 16.1) was marginally older than the age of Believers (M = 47.0, SD = 16.5), t(345) = 1.65, p =.099. Fifty-one percent of deniers voted for conservative parties, 32% for progressive parties, 6% independents and 11% expressed no voting preference. For Believers, 64% voted for progressive parties, 26% for conservative parties, 1% undecided and 9% expressed no voting preference. Our sample size was designed to be large enough to examine the additional factors of political preference (conservative v. progressive) and participant gender, but as these variables did not show any main effects or interactions, we report analyses without these variables. Whilst we would argue that the 45-minute exclusion is reasonable given the testing constraints, we also tested the robustness of the findings using different time cut-off points. Using a much stricter time cutoff (15 minutes, n = 310), patterns of significance were identical to the main analysis. Using no time cutoff (excluding only the nonsense/pattern-responding participants, n = 368), main effects remained significant for group (p <.001) and frame (p =.027), and no interaction was identified (p =.604). Post hoc tests comparing conditions showed significant difference between Real and Warmth conditions (p =.033), and a marginal difference S6

7 between Real and Development frames (p =.051). For Deniers only, the difference between Real and Warmth frames remained significant (p =.021), but the difference between Real and Development frames was no longer significant (p =.110). These findings could be interpreted as showing that the Warmth frame had more enduring effects than the Development frame. References (Supplementary Information) 1 Stern, P. C. Toward a coherent theory of environmentally significant behavior. Journal of Social Issues 56, (2000). 2 Stern, P. C., Dietz, T., Abel, T., Guagnano, G. A. & Kalof, L. A value-belief-norm theory of support for social movements: The case of environmentalism. Human Ecology Review 6, (1999). 3 Leviston, Z., Leitch, A., Greenhill, M., Leonard, R. & Walker, I. Australians views of climate change. (Commonwealth Scientific and Industrial Research Organisation, Canberra, Australia, 2011). 4 McCright, A. M. & Dunlap, R. E. Cool dudes: The denial of climate change among conservative white males. Global Environmental Change 21, (2011). S7