PoliClim aims at improving climate change scenario research by connecting political science research with integrated assessment modelling. Based on our prior work, it develops a model, which projects possible future trajectories of political institutions (accountability, rule of law and institutional capacity) for a set of different scenarios based on the SSP framework. PoliClim further establishes an interface to use these projections in the widely used REMIND (REgional Model for INvestments and Development) model developed by the Potsdam Institute for Climate Impact Research (PIK), linking political institutions to key transformation dynamics of the energy-economic system. PoliClim will explore how the quantitative integration of political institutions affects different future scenarios, allowing for an evaluation of political institutions as either enabler of or barrier for the transformation towards sustainability. In addition to this quantitative approach, PoliClim develops political extensions of existing scenario narratives, based on both theoretical and conceptual considerations and the empirical results of our modelling effort. Overall, PoliClim takes a new step in advancing the integration of political factors into widely used climate mitigation scenarios. It therewith positions political science in climate modelling and contributes to more reliable and usable scenarios.