In study 2, we examined whether we can replicate the findings of the positive relationships between climate change perceptions and different types of adaptation actions in a different country and in response to a related hazard, namely adaptation to heatwaves in the UK. Furthermore, the results from study 1 suggest that climate change perceptions may be more strongly related to the intention to take preparative adaptation behaviours that people more easily recognise as ways to reduce the risks from climate change. To test whether this is the case, we will experimentally vary how the risks that can be tackled by various adaptation actions are presented to participants: either explicating that the risks are caused by climate change (climate change condition) or without mentioning climate change (heatwave condition). As the experimental manipulation cannot influence preparative adaptation behaviour that people have already implemented, we did not examine past behaviour in this study. We consider a difference between the experimental conditions in the correlations between climate change perceptions and adaptation actions of .10 or larger a practically significant difference. To rule out common method variance, which may have played a role in study 1, we separated the measurement of climate change perceptions and adaptation actions across two measurement points in study 2. This study was preregistered on Open Science Framework (https://osf.io/rsbpq).
Method
Participants and procedure
Participants (n = 803, 35% men, 65% women, Mage = 37.8) were recruited via Prolific (prolific.co; for power analysis, see preregistration)Footnote 5 in late June. Only participants who indicated that their current country of residence was the UK and who were not studentsFootnote 6 were invited to participate. The questionnaire was completed in Qualtrics. After providing their informed consent to participate in the study, participants were randomly assigned to one of two conditions. In one condition, all adaptation actions were introduced as aimed at dealing with ‘heatwaves caused by climate change’ (the climate change condition, n = 402). In the other condition, adaptation actions were referred to as ways to deal with ‘heatwaves’ (the heatwave condition, n = 401).Footnote 7 The exact wordings in each condition are given below. We asked respondents about their climate change perceptions one week before we asked the same participants about their adaptation action intentions. Individual responses across the two sessions were coupled using the participants’ unique Prolific IDs.
Measures
Climate change perceptions
The perceived reality (M = 6.36, SD = 1.04), causes (M = 5.99, SD = 0.97), and consequences (M = 6.18, SD = 0.98) of climate change were measured in the same way as in study 1. Participants who selected ‘completely disagree’ or ‘disagree’ for the perceived reality of climate change were not provided with the items about the causes and consequences of climate change (N = 13; 1.6%).Footnote 8
Policy support
Participants indicated to what extent they opposed or supported the implementation of three different policies to reduce the negative consequences of heatwaves (caused by climate change)Footnote 9: investing public money in heat warning systems in every city so that people can better protect themselves against heatwaves (caused by climate change) (Mheatwave = 4.18, SDheatwave = 1.43, Mclimate = 4.47, SDclimate = 1.39), investing public money in making sure there are enough air-conditioned locations publicly available during heatwaves (caused by climate change) (Mheatwave = 4.49, SDheatwave = 1.60, Mclimate = 4.55, SDclimate = 1.55), investing in additional health care personnel to check on vulnerable populations such as the elderly and the chronically ill during heatwaves (caused by climate change) (Mheatwave = 5.53, SDheatwave = 1.31, Mclimate = 5.59, SDclimate = 1.29).Footnote 10 Responses were provided on a 7-point scale, ranging from ‘strongly oppose’ (1) to ‘strongly support’ (7). All policies were analysed separately.
Information seeking
Participants indicated the likelihood (on a 5-point scale, ranging from ‘not at all likely’ (1) to ‘very likely’ (5)) that they would consult three different information sources to help them prepare for heatwaves (caused by climate change): the National Health Service web page on coping with heatwaves (caused by climate change) (Mheatwave = 2.37, SDheatwave = 1.21, Mclimate = 2.64, SDclimate = 1.14), newspaper articles on coping with heatwaves (caused by climate change) (Mheatwave = 2.39, SDheatwave = 1.14, Mclimate = 2.60, SDclimate = 1.13), and weather forecasts and weather warnings for heatwaves (caused by climate change) (Mheatwave = 3.91, SDheatwave = 1.07, Mclimate = 3.71, SDclimate = 1.10). All information seeking items were analysed separately.
We next offered participants the possibility to look up information on adaptation to heatwaves (based on Kievik and Gutteling 2011). Specifically, participants indicated (‘yes’ or ‘no’) whether they would like to receive more information on how to reduce the negative consequences of heatwaves (caused by climate change) (% yesclimate = 30.8, % yesheatwave = 33.2%). At the end of the survey, participants who had indicated that they wanted more information were provided with a link to a webpage by the UK National Health Service on coping with heatwaves (caused by climate change).Footnote 11 It was recorded whether people clicked on the link or not (% clickedclimate = 24.2%, clickedheatwave = 27.1%).
Preparative adaptation intentions
We included eight preparative adaptation intentions: four that people could implement inside their home (putting up thermal curtains, replacing halogen or incandescent light bulbs with LED lightsFootnote 12, applying weather strips to doors and windows to keep warm air out, and applying sun-blocking film to windows) and four that people could implement outside their home or that required structural changes to the home (properly insulating loft and walls, planting plants and trees near property, painting external roof/walls in lighter colours, and installing awnings, overhangs, or other sun blinds for windows; based on Murtagh et al. 2019). To measure intentions, participants were asked to indicate how likely they were to take these measures within the next year to reduce the negative effects of heatwaves (caused by climate change). Responses were given on a 5-point scale ranging from ‘not at all likely’ to ‘very likely’. We also included the option ‘have already done this’, and included the option ‘not applicable’ for the outdoors/structural measures, since the measures may not be possible to complete for every participant (e.g. it is not possible to plant plants around the house if one does not have a garden). Respondents who indicated that they have already taken the measure or for whom the measure is not applicable are not included in the analyses, as only intentions are considered as relevant outcomes in the current study. All adaptation intentions were analysed separately, as we are interested in whether climate change perceptions are associated with different kinds of adaptation behaviours. The distribution of responses on these items is available in the Supplemental Material.
Manipulation check
We assume that if climate change is not explicitly mentioned, it is less likely that people consider climate change when thinking about natural hazards and ways to deal with them. We therefore asked participants at the end of the study to what extent they were thinking about climate change while completing the questionnaire (1 = ‘not at all’, 7 = ‘very much’).
Results
We first examined whether the experimental manipulation was successful. In both conditions, only a minority did not think at all about climate change (11% and 3.2% of participants selected response option ‘1’ in respectively the heatwave and the climate change condition). Yet, overall, participants in the climate change condition indeed thought more about climate change while completing the questionnaire than people in the heatwave condition (Mclimate = 5.45, Mheatwave = 4.59, t(773.7) = 6.99, p < .001), suggesting that the manipulation did make climate change overall more salient in the climate change condition. There were no a priori differences across conditions in perceptions of the reality (t(794.8) =−0.59, p = .55), causes (t(785.2) =−0.26, p = .80), and consequences of climate change (t(788) =−1.10, p = .27).
Policy support
In both conditions, stronger climate change perceptions were significantly associated with stronger support for policies to reduce the impact of heatwaves. Specifically, the more people agreed that climate change was real, caused by humans, and that climate change has negative consequences, the more they supported policies to reduce the negative impacts of heatwaves (r’s ranging from .11 to .38 across conditions, a small to medium-large effect size, see Table 2). The only exception occurred in the heatwave condition: there was no significant correlation between perceptions of the causes and consequences of climate change and supporting the policy to increase publicly available air-conditioned locations. The correlations in the climate change condition were at least .10 stronger than their counterparts in the heatwave condition, which we consider a practically significant difference (see Table 2). The strength of the correlations was comparable across the different climate change perceptions.
Table 2 Summary of the observed effect sizes across different adaptation actions for the three different climate change perception in study 2 Information seeking
In the heatwave condition, climate change perceptions were in most cases only marginally significantly positively associated with intentions to seek information (r’s ranging from .02 to .11, representing a non-significant effect to small effect). In the climate change condition, the more people agreed that climate change is real, caused by humans, and has negative consequences, the stronger their intention to seek information on heatwaves (r’s ranging from .08 to .25, generally representing a small to medium-sized effect, see Table 2). There were two exceptions: there were no significant correlations between perceptions of the consequences of climate change and intentions to consult the National Health Service web page or newspaper articles. The relationships between climate change perceptions and information seeking intentions were overall stronger in the climate change condition compared to the heatwave condition: the difference was greater than .10 for 4 out of 9 correlations, which we consider a practically significant difference. Again, the correlations were comparable between the different climate change perceptions.
In both conditions, we found that the more people perceived climate change as real, human-caused, and having negative consequences, the more likely they were to request information on coping with heatwaves (caused by climate change) at the end of the questionnaire (see Table 2). The strength of the relationship did not vary across the experimental conditions or the climate change perceptions (Cohen’s d ranging from .17 to .22, representing a small effect). The climate change perceptions were however not associated with whether people actually clicked the link to access the information (see Table 2), with the only exception that people in the climate change condition were more likely to click the link when they more strongly believed that climate change is human-caused (Mclick = 6.34, Mno click = 6.01, t(51.3) = 1.88, p = .03). Due to the small number of people that actually clicked the link and the high scores on the climate change perception items for people who requested to see more information, this comparison may be underpowered and prone to ceiling effects.
Preparative adaptation intentions
In both conditions, the climate change perceptions were hardly associated with intentions to take most measures. In the heatwave condition, climate change perceptions were not associated with intentions to implement any of the adaptation measures, with one exception: people who more strongly believed that climate change was real had slightly stronger intentions to plant plants around the home (r = .11, p = .05) (see Table 2). In the climate change condition, just four out of 24 correlations were significant: people had slightly stronger intentions to plant plants around the home the more they believed that climate change was real (r = .13, p = .03) and caused by humans (r = .14, p = .02). Also, people who more strongly believed that climate change was real had slightly stronger intentions to put up sun-blocking curtains (r = .12, p = .04). In contrast to what was expected, there was a weak significant negative correlation between the perceived consequences of climate change and intentions to implement sun-blocking film (r =−.10, p = .04): the more people expect negative consequences from climate change, the less they intend to apply sun-blocking film to their windows. Yet, all effect sizes are very small and barely significant.
Discussion
Overall, we found that stronger climate change perceptions were associated with stronger policy support and more information seeking, replicating the findings from study 1. However, we mostly did not replicate the finding that stronger climate change perceptions were associated with stronger intentions to take preparative adaptation measures, as we found only four positive significant correlations (out of 48). We found that explicitly introducing the adaptation actions as measures to adapt to climate change increased the strength of the relationship between climate change perceptions and policy support and information seeking intentions, but it did not strengthen the relationship between climate change perceptions and intentions to take preparative adaptation measures. Moreover, we found that people with stronger climate change perceptions were more likely to request information on adapting to heatwaves, irrespective of the experimental condition. Yet, we did not find consistent evidence that people who had stronger climate change perceptions were more likely to actually click the link to see more information, irrespective of the condition, but the test of this comparison was underpowered. Again, we did not find that any of the climate change perceptions was more strongly associated with the different indicators of adaptation actions than others.