Transboundary ecosystem service flows in Central Asia: Enhancing global sustainable development goals (SDGs) through the grain–water-carbon-culture network (GWCCN)

Transboundary ecosystem service flows (ESFs) are crucial links that connect natural and social systems across regions. With its unique geographical advantages, Central Asia serves as a strategic hub for regional and global connectivity, contributing to trade, cultural exchange, and technological development. This study presents a framework for understanding how ESFs support the achievement of SDGs in 7 transboundary countries and 195 nations globally, with a focus on the cross-border and remote effects of the grain–water–carbon–culture network (GWCCN) in Central Asia. Our findings highlight that water yield and soil conservation services in the Syr Darya and Amu Darya Basins were critical for downstream countries, with Uzbekistan and Turkmenistan relying on upstream flows from Tajikistan and Kyrgyzstan (30% and 21% deficits, respectively). Grain production was concentrated in Uzbekistan (35% of total flows), whereas carbon storage and habitat quality services were highly concentrated in the Fergana Valley (40% and 70%, respectively). Cross-border spillovers benefit neighboring countries and global regions. Approximately 20 million people rely on Central Asia–China transboundary rivers. Globally, water exports range from 0.3 to 82.17 billion t, grain exports range from 0.003 to 8.52 billion t, tourism and cultural flows attract 43.86 billion visitors, and carbon and habitat quality services cover 0.09–7.53 billion ha. Importantly, the ESFs of Central Asia significantly support SDG achievement, with contribution rates of 80–90% in China and Russia, 40–60% in Iran and Afghanistan, and < 10% in Pakistan, Azerbaijan, and Mongolia. Globally, the United States, India, and EU countries receive 43%, 36%, and 13–17%, respectively, supporting the SDGs related to food security, climate action, and socioeconomic development. Overall, Central Asia occupies a strategic position in the global ESF network. Its GWCCN-related ESFs are critical for regional and global ecological security, food provision, climate regulation, and SDG advancement, highlighting the need for coordinated management, sustainable utilization, and the promotion of trade, tourism, and cultural industries.