We implemented two survey-experiments to test the impact of conspiracy rhetoric on the views of US residents about the consequences of climate change and support for direct carbon capture. The first study focused on how receptive respondents were to a scientific report on the impacts of climate change when they were also presented with conspiracy-based criticism of the report’s conclusions. The second study explored how conspiracy rhetoric criticizing a report recommending the consideration of direct carbon capture influences support for the technology. We assess the effects of exposure to the conspiracy claims both in isolation and in contexts where scientific evidence contradicts the conspiratorial attack. We include a partisan source cue to test whether its presence enhances the impact of the messages on in-group partisans. The results accentuate the conditional nature of conspiracy rhetoric on views about the consequences of climate change and support for a novel climate geoengineering technology.