Recent scientific assessments of climate change have shifted towards evaluating solutions for removing atmospheric carbon dioxide (CDR). This paper reports a participation experiment in which we involved an interdisciplinary group of researchers in mapping issues relating to two CDR approaches: afforestation and bioenergy with carbon capture and storage (BECCS). We describe the responses of individual researchers when presented with visualisations aggregated from posts about afforestation and BECCS on the platform Twitter. We then compare the researchers’ responses with a qualitative analysis of a subset of the Twitter data. The analysis highlights challenges the researchers experienced in identifying issues and relating these visualisations to their own research on afforestation and BECCS. We discuss the prospects for bringing experimental approaches to mapping issues, publics and participation into closer relation with science and technology assessments. The paper concludes with reflections on the value of qualitative traditions of STS research for digital controversy analysis.