Scepticism in public attitudes towards climate change is seen as a significant barrier to public engagement. In an experimental study, we measured participants scepticism about climate change before and after reading two newspaper editorials that made opposing claims about the reality and seriousness of climate change (designed to generate uncertainty). A well-established social psychological finding is that people with opposing attitudes often assimilate evidence in a way that is biased towards their existing attitudinal position, which may lead toattitude polarisation. We found that people who were less sceptical about climate change evaluated the convincingness and reliability of the editorials in a markedly different way to people who were more sceptical about climate change, demonstratingbiased assimilationof the information. In both groups, attitudes towards climate change became significantly more sceptical after reading the editorials, but we observed no evidence ofattitude polarisationthat is, the attitudes of these two groups did not diverge. The results are the first application of the well-established assimilation and polarisation paradigm to attitudes about climate change, with important implications for anticipating how uncertaintyin the form of conflicting informationmay impact on public engagement with climate change.