Individual sustainable behavior is shaped by a broader socio-political context that either constrains or
facilitates available options. Understanding when and why people support climate policies designed to
promote systemic sustainability is crucial for effective climate change mitigation. The Integrative
Public Policy Acceptance (IPAC) Framework synthesizes key psychological determinants of public
policy acceptance into a unified model, highlighting the central role of individuals' Desire for
Governmental Intervention (DGI) (Grelle & Hofmann, 2024). The IPAC proposes that problem
awareness predicts policy acceptance, with this relationship mediated by DGI. Furthermore, support-
seeking characteristics, such as trust in government, control/responsibility attributions, and perceived
changeability are predicted to shape DGI, possibly in interaction with problem awareness. Policy
qualities, such as effectiveness, fairness, and regulatory depth, in turn, are expected to shape policy
acceptance, possibly in interaction with DGI. To test these predictions, we conducted a large online
study (n = 1000, n obs = 25080) across diverse environmental domains, including transportation, meat
consumption, housing, food waste, and fast fashion. Multilevel regression analyses provided strong
empirical support for many of the IPAC's proposed main links affecting DGI and acceptance, as well
as the mediation of the effect of problem awareness on acceptance via DGI. Subsequent moderator
analyses yielded more mixed results. Together, these findings underline the importance of addressing
psychological and contextual factors in designing climate policies. The IPAC offers valuable insights
for fostering public support for sustainability policies, contributing to climate change mitigation.