Insights into material use and economic decoupling in China’s infrastructure for sustainable development

Quantifying material use in infrastructure development and analyzing its relationship with economic growth is essential for enhancing resource efficiency and steering regional resource management toward sustainable development. This study systematically assessed infrastructure related material use in 30 provinces, autonomous regions, and municipalities in China during 1978–2022. The result indicated that material stock has experienced significant growth, increasing from 16.91×10 9 t in 1978 to 103.60×10 9 t in 2022, with an average annual growth rate of 4.20%. However, from 1978 to 2015, material input followed a strong upward trend but saturated after 2015. At the national level, material input peaked in 2015, after which it began to decline. The central region reached its peak earlier in 2013, while the eastern and western regions peaked in 2015. Using a decoupling analysis framework, this study revealed that nationally, the elasticity value between material stock and gross domestic product (GDP) remained near or above 1.0, reflecting continued reliance on stock accumulation. Regionally, the elasticity value between material stock and GDP has increased in the central and western regions during 1978–2022, whereas elasticity value between material stock and GDP in the eastern region showed a slower growth rate but still struggled to achieve absolute decoupling. Moreover, the elasticity value between material input and GDP has declined at the national level, presenting a relative decoupling, with some regions already achieving absolute decoupling. The eastern region was closer to absolute decoupling, while the central and western regions, though still intensive in material input, exhibited faster declines in elasticity. Accelerating the transition from linear to circular economy is an essential step for China to achieve absolute decoupling and long-term sustainability. Finally, this research recommends promoting the adoption of renewable energy, driving industrial upgrading, implementing compact urban design, and extending the lifespan of infrastructure to reduce material dependency and achieve sustainable infrastructure transformation at the national level.