Resource Systems Under Human Depopulation: The Case of Anthropocene Japan

Human activity has left an indelible and deepening imprint on Earth systems, prompting calls for formal recognition of the “Anthropocene” as a new geological epoch and raising concerns about a polycrisis of interlinked environmental, societal, and demographic disruptions. Among the drivers of this crisis, population growth is often identified as a key factor, which has spurred long debates over whether depopulation could mitigate the crisis. As more countries transition to sustained sub-replacement fertility, this premise has gained prominence. This thesis explores that assumption focusing on Japan, a vanguard depopulating country, to investigate the nexus among population change, resource systems, and sustainability. It begins by presenting a conceptual framework that places the Anthropocene crisis within the population-society-environment nexus and critiques reductionist views that single out population as the principal driver. It then explores the Resource Nexus literature on land, food, water, and energy to highlight geographic and thematic biases in how socio-demographic challenges are addressed. Building on these insights, two empirical analyses of Japan are undertaken: a Bayesian causal analysis of the population-economy-land-food-water-energy nexus, and a multiregional input-output analysis to assess the land-water-greenhouse-gas emissions nexus embedded in resource consumption. Findings indicate that Japan’s depopulation has yielded measurable reductions in resource demand across multiple sectors, yet these also entail risks of food insecurity and footprint offshoring as domestic cropland use shrinks and trade dependency grows. Further, despite a shrinking population, absolute food system footprints have remained stable while per-capita shares have risen by nearly one-third over the past decade, driven by overconsumption of animal-based and ultra-processed foods, most of which are externalised through global supply chains. The thesis argues that, although depopulation could theoretically yield environmental dividends, affluence and pro-growth lock-in limit these gains. It, therefore, calls for transformational societal changes to achieve sustainable resource management and safely navigate the Anthropocene crisis.