Understanding public acceptance of climate policies is critical for their successful implementation. This study examines how information on carbon impacts of specific lifestyle domains influences support of policies aiming to change behavior in these domains . We focused on heating, mobility, and diet—domains often underestimated in their climate relevance in Germany—and conducted a randomized between-subject online experiment (N = 559) with a representative sample of German adults. Participants received one of four information treatments: no information (Control Group, CG), non-differentiating information emphasizing general importance (Experimental Group 1, EG1), or information highlighting differences in impact either through ranked order (Experimental Group 2, EG2) or absolute tons of CO2eq (Experimental Group 3, EG3).
Differentiating information (EG2 and EG3) influenced impact estimations, evaluations of policy effectiveness, and policy support—but only in the heating domain. The format of differentiation (EG2 ranked vs. EG3 absolute tons) did not produce different outcomes. Mediation analyses using the Greed-Efficacy-Fairness (GEF) model showed that perceived policy effectiveness mediated the effect of impact information on policy support. Across all domains, environmental concern was the strongest predictor of policy support and also explained substantial variance (16-33%) in perceived policy effectiveness. Findings suggest that information about carbon impacts can influence policy support in domains where carbon impacts are underestimated.