Abstract
Sustainable cities (SDG 11) demand equitable resource governance, yet existing studies neglect hidden environmental costs embedded in inter-regional trade. Using a multi-regional Input-Output (MRIO) model, we analyze China’s virtual water (VW) and virtual carbon credit (VCC) flows (2002-2017). We propose the Environment-Trade Comparative Advantage (ETCA) index to embed ecological indicators into trade analysis. Results reveal 72% of VW and 85% of VCC flow from water-scarce northern regions to affluent coastal cities, suppressing exporters’ GDP by 6-9% annually a pattern mirroring Global North-South exploitation. Traditional metrics overvalue resource-intensive sectors by 18-35%, while ETCA prioritizes regions with balanced ecological-economic efficiency. Policy simulations show ETCA-guided compensation could reduce disparities by 22-40%, and water-carbon labeling empowers sustainable consumption. This work addresses SDG 11’s blind spot uncounted virtual resource flows and redefines urban sustainability monitoring. Findings urge integrating ETCA into SDG frameworks to prevent trade-driven inequities, offering a model for Global South cities pursuing post-SDG resilience.
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Data availability
In an effort to make this study reproducible, the data used to produce the results have been made publicly available in figshare (https://doi.org/10.6084/m9.figshare.28622963). Any remaining data are available from the corresponding author on reasonable request.
Code availability
The relevant formulas in this study are calculated using the built-in functions of MATLAB. For specific calculation formulas, please refer to “Methods.”
References
Tan, S. & Yao, L. Managing and optimizing urban water supply system for sustainable development: perspectives from water-energy-carbon nexus. Sustain. Prod. Consum. 37, 39–52 (2023).
Sachs, J. D. et al. Six transformations to achieve the sustainable development goals. Nat. Sustain. 2, 805–814 (2019).
Li, X., Huang, G., Wang, S., Zhang, X. & Luo, B. Synergistic management of water, energy, and carbon: a case study from Shandong province, china. Appl. Energy 381, 125192 (2025).
Xu, Z. et al. Assessing progress towards sustainable development over space and time. Nature 577, 74 (2020).
Zhang, S. et al. Targeting net-zero emissions while advancing other sustainable development goals in China. Nat. Sustain. 7, 1107–1119 (2024).
Wang, S., Wang, Z. & Fang, C. Evolutionary characteristics and driving factors of carbon emission performance at the city level in China. Sci. China Earth Sci. 65, 1292–1307 (2022).
Cheng, L., Mi, Z., Sudmant, A. & Coffman, D. Bigger cities better climate? Results from an analysis of urban areas in China. Energy Econ. 107, 105872 (2022).
Qin, J. & Gong, N. The estimation of the carbon dioxide emission and driving factors in China based on machine learning methods. Sustain. Prod. Consum. 33, 218–229 (2022).
Huang, H. W. et al. Agricultural and energy products trade intensified the water scarcity in the grain and energy base in northern China. Agric. Water Manag. 307, 109208 (2025).
Sun, J. et al. “Water-carbon” redistribution caused by China’s interprovincial grain transportation. Water Res. 235, 119894 (2023).
Wang, Z., Zhang, H., Li, H., Wang, S. & Wang, Z. Identifying the key factors to China’s unsustainable external circulation through the accounting of the flow of embodied energy and virtual water. Renew. Sustain. Energy Rev. 173, 113115 (2023).
Fishelson, G. The allocation and marginal value product of water in Israeli agriculture. in Studies in Environmental Science Vol. 58 (eds Isaac, J. & Shuval, H.) 427–440 (Elsevier, 1994).
Allan, J. A. Virtual water - the water, food, and trade nexus useful concept or misleading metaphor?. Water Int. 28, 106–113 (2003).
Allan, J.A. Fortunately There Are Substitutes for Water Otherwise Our Hydropolitical Futures Would Be Impossible, Priorities for Water Resources Allocation and Management. 13−26, https://www.scirp.org/reference/ReferencesPapers?ReferenceID=1505269 (Overseas Development Administration, London, 1993).
Hoekstra, A.Y. Virtual Water Trade. In Proceedings of the International Expert Meeting on Virtual Water Trade. Value of Water Research Series. 12, https://www.scirp.org/reference/referencespapers?referenceid=1505273 (2003).
Hoekstra, A. Y. & Wiedmann, T. O. Humanity’s unsustainable environmental footprint. Science 344, 1114–1117 (2014).
Hoekstra, A. Y. Human appropriation of natural capital: a comparison of ecological footprint and water footprint analysis. Ecol. Econ. 68, 1963–1974 (2009).
Hoekstra, A. Y. & Mekonnen, M. M. The water footprint of humanity. Proc. Natl. Acad. Sci. USA 109, 3232–3237 (2012).
Bai, Y. et al. Tele-connections, driving forces and scenario simulation of agricultural land, water use and carbon emissions in China’s trade. Resour. Conserv. Recycl. 203, 107433 (2024).
Peng, S. et al. Unequal transfer and its policy implications of carbon emissions and economic benefits embodied among central plains urban agglomeration. Urban Clim. 54, 101858 (2024).
Zhang, H. et al. Worsening carbon inequality embodied in trade within China. Environ. Sci. Technol. 57, 863–873 (2023).
Zhang, Z., Shi, M., Chen, K. Z., Yang, H. & Wang, S. Water scarcity will constrain the formation of a world-class megalopolis in north China. npj Urban Sustain. 1, 13 (2021).
Zhang, C. & Anadon, L. D. A multi-regional input-output analysis of domestic virtual water trade and provincial water footprint in China. Ecol. Econ. 100, 159–172 (2014).
An, T. et al. Simulation of the virtual water flow pattern associated with interprovincial grain trade and its impact on water resources stress in China. J. Clean. Prod. 288, 125670 (2021).
Li, W. et al. Assessment of greenhouse gasses and air pollutant emissions embodied in cross-province electricity trade in China. Resour. Conserv. Recycl. 171, 105623 (2021).
He, K., Mi, Z., Zhang, J., Li, J. & Coffman, D. The polarizing trend of regional CO2 emissions in China and its implications. Environ. Sci. Technol. 57, 4406–4414 (2023).
Feng, K., Hubacek, K., Siu, Y. L. & Li, X. The energy and water nexus in Chinese electricity production: a hybrid life cycle analysis. Renew. Sustain. Energy Rev. 39, 342–355 (2014).
Wang, X.-C. et al. Water-energy-carbon emissions nexus analysis of China: an environmental input-output model-based approach. Appl. Energy 261, 114431 (2020).
Zhu, Y. et al. Life-cycle-based water footprint assessment of coal-fired power generation in China. J. Clean. Prod. 254, 120098 (2020).
Chini, C. M. & Peer, R. A. M. The traded water footprint of global energy from 2010 to 2018. Sci. Data 8, 7 (2021).
Yin, Y. et al. Environmental impact of grain virtual water flows in China: from 1997 to 2014. Agric. Water Manag. 256, 107127 (2021).
Wei, W. et al. Embodied greenhouse gas emissions from building China’s large-scale power transmission infrastructure. Nat. Sustain. 4, 739–747 (2021).
Chen, J., Xie, Q., Shahbaz, M., Song, M. & Wu, Y. The fossil energy trade relations among BRICS countries. Energy 217, 119383 (2021).
Toraubally, W. A. Comparative advantage with many goods: new treatment and results. Eur. J. Oper. Res. 311, 1188–1201 (2023).
Chen, Q. et al. The effect of energy-water nexus on single resource system in urban agglomerations: analysis based on a multiregional network approach. Appl. Energy 378, 124781 (2025).
Ortuzar, I., Serrano, A., Xabadia, A. & Brouwer, R. Balancing efficiency and inequality in a non-linear multi-regional water allocation optimization model. Environ. Resour. Econ. 88, 761–794 (2025).
Distefano, T., Saldarriaga Isaza, A., Munoz, E. & Builes, T. Sub-national water-food-labour nexus in Colombia. J. Clean. Prod. 335, 130138 (2022).
Lv, C., Xu, X., Guo, X., Feng, J. & Yan, D. Basin water ecological compensation interval accounting based on dual perspectives of supply and consumption: taking Qingyi River Basin as an example. J. Clean. Prod. 385, 135610 (2023).
Xu, H., Chen, L. & Li, Q. Research on two-way ecological compensation strategy for transboundary watershed based on differential game. J. Environ. Manag. 371, 123314 (2024).
Yang, Y., Zhang, Y., Yang, H. & Yang, F. Horizontal ecological compensation as a tool for sustainable development of urban agglomerations: exploration of the realization mechanism of Guanzhong Plain urban agglomeration in China. Environ. Sci. Policy 137, 301–313 (2022).
Yu, B. & Xu, L. Review of ecological compensation in hydropower development. Renew. Sustain. Energy Rev. 55, 729–738 (2016).
Huang, W. et al. Review of recent progress of emission trading policy in China. J. Clean. Prod. 349, 131480 (2022).
Liu, L., Chen, C., Zhao, Y. & Zhao, E. China׳s carbon-emissions trading: overview, challenges and future. Renew. Sustain. Energy Rev. 49, 254–266 (2015).
Zakeri, A., Dehghanian, F., Fahimnia, B. & Sarkis, J. Carbon pricing versus emissions trading: a supply chain planning perspective. Int. J. Prod. Econ. 164, 197–205 (2015).
Vos, J. The political ecology of our water footprints: rethinking the colours of virtual water. World Dev. 185, 106801 (2025).
Du, J. et al. Trade-driven black carbon climate forcing and environmental equality under china’s west-east energy transmission. J. Clean. Prod. 313, 127896 (2021).
Sun, J. et al. Evaluating grain virtual water flow in China: patterns and drivers from a socio-hydrology perspective. J. Hydrol. 606, 127412 (2022).
Cai, J., Xie, R., Wang, S., Deng, Y. & Sun, D. Patterns and driving forces of the agricultural water footprint of Chinese cities. Sci. Total Environ. 843, 156725 (2022).
Xia, C. et al. The evolution of carbon footprint in the Yangtze River Delta city cluster during economic transition 2012-2015. Resour. Conserv. Recycl. 181, 106266 (2022).
Zhu, M. et al. Unfolding the evolution of carbon inequality embodied in inter-provincial trade of China: network perspective analysis. Environ. Impact Assess. Rev. 97, 106884 (2022).
Wang, Q., Yang, X. & Li, R. Are low-carbon emissions in the south at the cost of high-carbon emissions in north China? A novel assessment. Environ. Impact Assess. Rev. 105, 107426 (2024).
Tan, F., Xu, F., Bao, S. & Niu, Z. Carbon-trade nexus: the embodied carbon emission transfer network of China’s sustainable development demonstration belt. Sustain. Dev. 33, 621–635 (2025).
Zhang, Z., Shi, M. & Yang, H. Understanding Beijing’s water challenge: a decomposition analysis of changes in Beijing’s water footprint between 1997 and 2007. Environ. Sci. Technol. 46, 12373–12380 (2012).
Qian, Y. et al. Water footprint characteristic of less developed water-rich regions: case of Yunnan, China. Water Res. 141, 208–216 (2018).
Qian, Y. et al. Driving factors of agricultural virtual water trade between China and the Belt and Road countries. Environ. Sci. Technol. 53, 5877–5886 (2019).
Zhao, D., Liu, J., Yang, H., Sun, L. & Varis, O. Socioeconomic drivers of provincial-level changes in the blue and green water footprints in China. Resour. Conserv. Recycl. 175, 105834 (2021). Comparative advantage, demand for external finance, and financial development.
Hinloopen, J. & van Marrewijk, C. Power laws and comparative advantage. Appl. Econ. 44, 1483–1507 (2012).
Acknowledgements
The researchers were supported by the National Natural Science Foundation of China (42377346, U22A20613).
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X.G. and H.H. conceived the study. H.H., M.F., and X.Z. curated the data. H.H. and X.Z. conducted the formal analysis. X.N.Z., X.G., and Y.Z. acquired the funding. H.H. and M.F. developed the methodology. X.N.Z. and X.G. administered the project. H.H., M.F., and X.Z. performed the software implementation. X.G., X.N.Z., Yg.Z., and S.Y.Z. supervised the research. X.G., Yg.Z., and S.Y.Z. validated the results. H.H., M.F., and X.Z. created the visualizations. H.H. wrote the original draft. H.H., M.F., X.Z., and X.N.Z. reviewed and edited the manuscript. All authors reviewed and approved the final version of the manuscript.
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Huang, H., Fan, M., Zhang, X. et al. China’s mega-city clusters grab water resources and carbon credit from vulnerable hinterlands. npj Urban Sustain (2026). https://doi.org/10.1038/s42949-025-00279-9
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DOI: https://doi.org/10.1038/s42949-025-00279-9
