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

Labor Party–compete for government. Each of the 151 seats in the lower House of Parliament corresponds to an electorate which is a defined geographical area. The winner of the electorate is whichever candidate wins 50% plus one vote in a preferential voting system. Minor parties and independents hold some seats and otherwise influence the flow of preferences to the major parties. Marginal or swing seats matter more for determining the outcome of an election than do safely held seats. Importantly, patterns in aggregate public opinion do not necessarily translate to election outcomes if these patterns are unevenly distributed across the electorates. The second federal house of government, the Senate, uses state based proportional voting, however, unlike the House of Representatives, a majority in the Senate does not in itself lead to forming government. As a consequence of these factors, election campaigning routinely focuses on marginal seats, sometimes requiring a balance between messaging on local and national issues. The Coa- lition victory in the 2019 federal election benefitted from a strong result in the state of Queens- land, where the Coalition won 23 out of 30 seats (up from 21 in the 2016 election) [32, 33]. The Coalition’s campaigning in Queensland included narratives about economic and employment costs of climate action [23, 24, 34, 35]. However, economic policy was a dominant point of comparison between the two parties’ policy platforms nationally and in Queensland, as were dynamics of party leadership dynamics and personalities.

An exploration of the social-political determinants of Australians’ attitudes toward climate change and how these attitudes are positioned in relation to voting behaviour yields potentially important insights. For Australia, there are questions about whether climate change is an issue of significance to a large enough proportion of the voting population that it may come to decide future election outcomes based on demand for ambitious action, rather than fear of the social and economic impacts of climate policy [e.g. 2]. Australia’s experience may offer insights for other nations, particularly Anglophone countries with similar culture and systems of governance. Materials and methods We analysed quantitative survey data canvassing climate opinion, political voting behaviour, and a range of demographic measures. These data were collected via inclusion of specific ques- tions in the Life In Australia online panel [36] in July 2019 along with a range of questions administered for the Australian Election Study (AES) [31]. The online panel includes a large set of information on respondents’ personal, social and economic characteristics. Our explora- tion of climate opinion in the context of the 2019 federal election was informed by a combina- tion of the significance of the election outcome for climate policy in Australia, and the vast body of evidence that implicates political affiliation and ideology as a significant driver of cli- mate opinion in Australia [4, 5, 37–40]. To identify the determinants of climate opinion and voting preferences, we analysed our

data using ordinal logistic regression (OLR) models, a suitable analytical approach for ordinal survey data [41]. Following this, we created simplified population ageing scenarios to project an approximation of how aggregate public opinion may shift in the future. Survey instrument The survey contained three sections: climate opinion, voting preferences at the May 2019 fed- eral election, and a number of standard demographic variables. Questions and response options are available in Supporting information A. On climate opinion, we asked participants four questions interrogating various dimensions of climate opinion and voting preferences: 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 3 / 18