Climate change denial has been found to correlate with sociopolitical ideology. The general aim of the present thesis was to investigate this relation, and more specifically to 1) test the unique effects of intercorrelated ideological variables on denial, and 2) investigate the psychological underpinnings of the ideology-denial relation. This approach helps estimating what component of right-wing ideology better explains climate change denial; resistance to change (indexed by left-right/liberal-conservative political orientation, right-wing authoritarianism, and system justification), or acceptance of inequality (indexed by social dominance orientation [SDO]). In Paper I, SDO outperformed the effects of right-wing authoritarianism and political left-right orientation on denial (Study 1 and 2). Further, the SDO-denial relation was stable when denial scores were experimentally lowered by a newscast that communicated supportive evidence for climate change (Study 2). Thus, the following studies focused specifically on the SDO-denial relation by testing path models that also included other ideological variables (political conservatism, system justification, and endorsement of nature dominance), as well as personality variables (dominance, empathy, openness to experience, and anxiety avoidance) and/or gender. In Paper II, SDO and endorsement of nature dominance explained unique parts of climate change denial, and both of these variables mediated the effects of system justification and (low) empathy on denial. SDO mediated also the effect of dominance. In Paper III, focusing specifically on denial of human-induced climate change, SDO either partially or fully mediated the effects of political conservatism and gender across two cultural contexts (Brazil and Sweden). Additional analyses extended these results, by building on the model presented in Paper II. These analyses showed that SDO (and in some cases also political conservatism and endorsement of nature dominance) fully mediated the effects of gender and personality variables on denial, with one exception: Predisposition to avoid experiencing anxiety predicted denial directly, as well as through a link via general conservative ideology (system justification or political conservatism). In sum, the results indicate that denial is more strongly and consistently predicted by SDO than by the other included variables. Thus, endorsement of group-based inequality/hierarchies offers an important explanation for climate change denial.