Performative Modes of Modeling the Future: A Comparison of Two Club of Rome Reports

Predictive models increasingly function not only as representations of possible futures but as action-guiding instruments that orient present decision-making, a point emphasized in the growing literature on modeling for policy. Building on recent calls for a hermeneutic turn in Technology Assessment-especially Grunwald’s claim that models carry implicit narratives, values, and audience assumptions-this paper investigates a dimension that has received little explicit attention: the affective and motivational ways in which models seek to provide pragmatic orientation. We introduce the concept of performative modes to capture ideal-typical ways in which model-based futures are designed to intervene in their present (e.g., to warn, reassure, instill hope, or recommend action), rather than merely informing audiences. Methodologically, we develop a hermeneutic approach to model-text conglomerates and apply it comparatively to two influential reports to the Club of Rome: The Limits to Growth (1972) and its 50-year update Earth for All (2022). We reconstruct each report’s structure, modeling architecture, the role of technology, and rhetorical framing, drawing on the reports' texts, contextual materials, and reception to interpret how modeled scenarios position and mobilize their readership. Our analysis shows a marked shift in performative orientation. Limits to Growth combines a technocratic posture with an upstirring warning mode: it foregrounds epistemic novelty and dramatizes «overshoot and collapse» to generate awareness and trigger debate, while offering comparatively abstract guidance. Earth for All, by contrast, largely presupposes public awareness and deploys a hopeful, action-oriented mode: it frames a «Giant Leap» as feasible, centers wellbeing metrics, personalizes futures through narrative devices, and provides concrete policy roadmaps and calls for civic mobilization — while still relying on technocratic assumptions of agency within the modeling framework. We conclude that «performative modes» are a productive heuristic for Hermeneutic Technology Assessment, revealing how models' pragmatic force depends on audience presuppositions, affective address, and the unstable boundary between neutral projection and normative intervention.