While there is a strong relationship between climate change and human food consumption, it is challenging to understand the implications and impact from an individual perspective. The lack of a shared frame of reference, that allows people to compare their impact to others, limits awareness on this complex topic. To support group reflections and social comparison of the impact of people’s food consumption on climate change, we designed Econundrum, a shared physical data sculpture that visualizes carbon emissions resulting from dietary choices of a small community. Our three-week field study demonstrates how Econundrum helped people (i) understand the climate impact of various food types, (ii) reflect on the environmental impact of their food choices; and (iii) discuss the relation between climate impact and food consumption with others. Our study shows how a shared physical data sculpture mediates a complex topic to a community by facilitating the social dynamics in context.