We conducted a two-nation study (United States, n = 1500; England, n = 1500) to test a novel theory of science communication. The cultural cognition thesis posits that individuals make extensive reliance on cultural meanings in forming perceptions of risk. The logic of the cultural cognition thesis suggests the potential value of a distinctive two-channel science communication strategy that combines information content (“Channel 1”) with cultural meanings (“Channel 2”) selected to promote open-minded assessment of information across diverse communities. In the study, scientific information content on climate change was held constant while the cultural meaning of that information was experimentally manipulated. Consistent with the study hypotheses, we found that making citizens aware of the potential contribution of geoengineering as a supplement to restriction of CO2 emissions helps to offset cultural polarization over the validity of climate-change science. We also tested the hypothesis, derived from competing models of science communication, that exposure to information on geoengineering would provoke discounting of climate-change risks generally. Contrary to this hypothesis, we found that subjects exposed to information about geoengineering were slightly more concerned about climate change risks than those assigned to a control condition.