Australian voters’ attitudes to climate action and their social-political determinants

1. In your view, how important or unimportant is it that Australia takes action to reduce greenhouse gas emissions in order to help limit future climate change? (Measures of importance) 2. In your view, which energy source or mix of energy sources should provide Australia’s elec- tricity in 2050? (Various fuel sources and combinations of sources) 3. To what extent are you prepared to accept a personal cost in order to support action to reduce Australia’s emissions? (Personal costs and implications for others) 4. How much did the issue of climate change influence your vote in the 2019 Federal election? For you personally, would you say climate change was. . .? (Measures of importance to vote) Participants responded to each climate opinion question on an ordinal scale (except for Q2 which was categorical). For each question, we were interested in both describing broad trends and interrogating the determinants of variation among the respondents. Question 1 was intended to verify trends from public polling in aggregate Australian public opinion on climate change. In this way, we did not examine trends in specific or swing electorates [e.g. 42] but instead focused on aggregate public opinion in recognition of the policy relevance of such a measure [43, 44]. Question 2 sought to describe preferences for energy sources, given the centrality of the energy sector to climate policy debates in Australia [34, 45]. In question 3 we considered the willingness for individuals to make a sacrifice in order to support cli-

mate policy initiatives. This is in recognition of the pernicious attitude-behaviour gap that has seen limited climate-related behaviour change even in settings where opinion is broadly aligned with such goals [38, 46, 47]. Question 4 placed climate opinion in the voting context, to examine to what extent Australian voters factored climate change into their decisions for allocating their primary vote in the House of Representatives in the May 2019 federal elec- tion. Question 4, then, was intended to examine whether the 2019 election (held around two months before the survey) was indeed the ‘climate election’ in the minds of Australian voters. Voting preference at the May 2019 federal election was measured categorically in line with the Australian Election Study approach. Participants were asked “In the Federal election for the House of Representatives on Saturday 18 May, which party did you vote for first in the House of Representatives?”, and provided with a list of all political parties. For the purposes of our analysis, we aggregated into the major parties (plus independent/other): Liberal Party (centre-right/right; conservative), Labor Party (centre-left; progressive), The Greens (left; pro- gressive), The Nationals (centre-right/regional issues; conservative), The Liberal-National Party (centre-right/right; conservative; present in Queensland only as a formal merging of the two Coalition partner parties into the LNP). While the Liberal and National Parties co-govern as a Coalition, due to differences between the results corresponding to the two parties we

maintained the distinction in the analysis. The formal merger of the two parties in Queensland complicates the analysis as we did not want to aggregate LNP voters into either Liberal or National Party voters. Therefore, we also analysed the LNP separately alongside the Liberal and National Parties. We accessed the standard demographic variables collected for the Australian Election Study. These were: state of residence (categorical), residence in capital city or non-capital city (binary categorical), socio-economic index for area of residence (ordinal), gender (categori- cal), age (numerical), country of birth (categorical), citizenship (binary categorical), language (binary categorical), income (ordinal). PLOS ONE Australian voters’ attitudes to climate action and their social-political determinants PLOS ONE | https://doi.org/10.1371/journal.pone.0248268 March 24, 2021 4 / 18