Does Human Depopulation Reduce Resource Consumption? Evidence from Anthropocene Japan

Humanity’s deepening strain on Earth systems has sparked widespread discussion of an “Anthropocene crisis,” often attributed to overpopulation. This raises the question: if overpopulation underpins the crisis, does its resolution lie in depopulation? Here, we examine the effects of Japan’s ongoing depopulation on the nexus of population, economy, cropland use, food, water, and energy. We take a systematic Bayesian approach to examine changes in the strength and direction of causality among these variables and explore plausible future pathways under Shared Socioeconomic Pathway (SSP) scenarios. We find that, while depopulation has led to reductions in resource demand, notably for water and energy, impacts on the food system are more complex due to interdependencies with economic and other factors beyond population change. In conclusion, we argue that it will take longer than predicted for depopulation dividends to materialize at a scale that could meaningfully contribute to addressing the crisis, and that proactive efforts to reshape consumption patterns and restructure economic systems, from a model predicated on perpetual growth to one oriented toward sufficiency, are necessary to capitalize on the potential dividends offered by this demographic shift.