Towards ecological sustainability: The progress and spatio-temporal evolution of green development in China

China is actively exploring innovative models for green development guided by the Two Mountains Theory to form a path for achieving ecological sustainability. Based on the interpretation of green development within the framework of Two Mountains Theory, this study constructed a comprehensive index system of 18 indicators, including ecological wealth, economic wealth and transformation channels, measured the green development of 31 provinces in China from 2004 to 2022, and analyzed the regional differences and dynamic evolution rules. The results show that China's pursuit of green development under the framework of Two Mountains Theory is advancing steadily, and the two-mountains green development index shows a significant upward trend with minor fluctuations. Although there are regional differences in the two-mountains green development index, there is a significant spatial correlation, and the spatial agglomeration state is relatively stable. In addition, the two- mountains green development index has gradually increased over time, and the absolute difference between regions has also continued to expand. The probability of leapfrog green development in each province is low, and the spatial spillover effect is large. Green development shows the phenomena of sigma convergence and beta convergence, which converge to the steady state in the long run. The random forest approach proves the importance of ecological industrialization, and the index system has high contribution in predicting the spatio-temporal evolution of China's green development led by the Two Mountains Theory.