Abstract A basic understanding of climate politics is necessary for citizens to assess their government’s policies on mitigating and adapting to climate change. However, research on knowledge about climate change has focused on causes and consequences of climate change rather than climate politics. Even less research has focused on the learning process rather than knowledge. Therefore, this study explores which factors influence learning about climate politics from media use and interpersonal communication. We test a set of factors related to the individual respondent and the type of information sources used. Data from a three-month panel survey conducted in the context of the 2015 UN climate conference in Paris (COP21) is analyzed using hierarchical regression analyses. The strongest explanatory factor is prior knowledge – which, in contrast to the knowledge gap hypothesis, makes learning less likely. The most plausible explanation for this ceiling effect is a lack of background information offered in the most widely used journalistic media. Keywords Knowledge acquisition, Panel survey, media effects, climate change, knowledge gap