Limits to growth revisited: System dynamics simulations of global economic developments and distributional implications in the 21st century
使用系统动力学模型模拟120种情景，发现92%的模拟中全球产出在2100年前达到峰值并持续下降，高增长情景最终面临经济崩溃，而资源枯竭和气候变化是压力因素，但劳动力短缺是增长停滞的主因。
We use a system dynamics environment-economy model to explore how multiple limits to growth may affect global economic output and consumption across different social classes until 2100. Based on a five-dimensional scenario space, we simulate global economic development in 120 scenarios that differ in labor productivity growth, per-capita consumption growth, fossil resource availability, climate change severity, and climate system sensitivity. In 92% of the simulations, output peaks and then declines persistently. Excluding scenarios without climate impacts, output in 2100 is 15–70% lower than in 2019. Scenarios with low labor productivity and consumption growth experience earlier peaks at lower levels and moderate output declines. In contrast, scenarios with high labor productivity and consumption growth show faster and longer periods of growth but eventually face economic collapse. While resource depletion and climate damages act as stressors, most simulations indicate that growth ultimately halts and reverses due to a shortage of labor hours. During the phase of unintentional economic degrowth, economic convergence and redistribution reduce consumption in high-income countries to values 3–4 times lower than initial consumption levels, while middle- and low-income countries return to consumption levels similar to those at the start of the simulations. Poverty reduction in poorer regions ends as global output peaks, while environmental destabilization caused by economic growth threatens development opportunities beyond the 21st century.