Digital Twins of the Earth Between Vision and Fiction

Abstract Digital replicas (or twins) of the entire planet and of its inhabitants are being actively proposed by the research community for a variety of purposes, with a focus on climate adaptation and mitigation. Since mathematical modelling is at the core of this digital enterprise, we undertake to explore the possible limits of models in creating twins of the Earth by recalling some of the existing visions about the nature and function of mathematical models. We thus discuss what models are, what their function is in relation to the production of knowledge, and how one can question if a model is fair, by keeping the digital twins as the focus of our analysis. This leads us to discuss the way models intervene in the democratic process and orient power toward those who wield the models, and what these artifacts represent in the context of governance of science itself.