Recently, Professor Wang Heming's team from the School of Metallurgy, NEU has made significant progress in the global research on the water footprint of materials production. The research findings, titled "Doubling of the global freshwater footprint of material production over two decades," were published in Nature Sustainability, a prestigious journal within the Nature family (Impact Factor: 27.1). Wang Yao, a doctoral candidate from the School of Metallurgy, NEU, and Dr. Ma Fengmei from the Institute of Urban Environment, Chinese Academy of Sciences, serve as co-first authors. Professor Wang Heming from the School of Metallurgy at NEU, and Professor Asaf Tzachor affiliated with both the University of Le Mans and the University of Cambridge, are co-corresponding authors, with NEU’s School of Metallurgy as the first completing institution. Co-authors of the paper also include Dr. Jiang Meng and Professor Edgar Hertwich from the Norwegian University of Science and Technology, Professor Fang Kai from Zhejiang University, Professor Liang Sai from Guangdong University of Technology, Professor Zhu Bing from Tsinghua University, Professor Manfred Lenzen from the University of Sydney, Professor Heinz Schandl from the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia, and Professor Stephan Lutter from the Vienna University of Economics and Business. This paper marks the first publication by NEU as the lead institution in Nature Sustainability. It also represents the team's second paper in the field of water footprint of material production, following their previous findings published in Nature Water.
Materials serve as a vital foundation for the operation of modern economies and the construction of infrastructure. Key materials such as steel, copper, aluminum, cement, plastics, rubber, and paper are widely used across all sectors of human production and daily life, yet their production hides enormous freshwater consumption. As global industrialization and urbanization advance and economic scale continues to expand, water withdrawals for material production have been rising steadily, further exacerbating water scarcity in certain regions. For a long time, academic research has focused relatively extensively on agricultural water use, while insufficient attention has been paid to freshwater consumption in non-agricultural sectors, particularly in material production processes. This has resulted in a persistent lack of systematic understanding regarding the global impact of material production on water resources. In the face of increasingly severe water scarcity and sustainable development challenges, scientifically assessing the water footprint of material production and revealing its spatiotemporal patterns and driving factors holds significant scientific and practical value. This contributes to promoting industrial water conservation and emission reduction, improving global water resource management systems, and helping achieve the United Nations Sustainable Development Goal 6 (SDG 6: Clean Water and Sanitation).
Based on the environmentally extended multi-region input-ouput model and the hypothetical extraction method, this study constructs a material-water resource coupling model. It quantifies the blue water footprint associated of 16 categories of global metallic and non-metallic material production from 1995 to 2021, and analyzes their regional variations and the characteristics of virtual water flows in international trade. The blue water footprint of material production refers to the total volume of surface water and fresh groundwater directly or indirectly consumed during the production process. The research systematically reveals a significant upward trend in the blue water footprint of global material production over the past three decades, along with its spatial variation characteristics. First of all, the overall scale of the blue water footprint in global material production continues to expand. Driven by economic growth and increased material consumption, the global blue water footprint of material production doubled between 1995 and 2021, growing significantly faster than overall global water use. Secondly, the blue water footprint of various materials production has shown an upward trend, with steel experiencing the most significant increase—approximately threefold—making it the category consuming the most freshwater globally in material production. This is followed by basic industrial materials such as aluminum, cement, and other metals. Additionally, the spatial distribution of the water footprint from material production has shifted, with East Asia, South Asia, and Oceania emerging as the primary regions driving global growth in the blue water footprint of material production. In contrast, countries within the Organisation for Economic Co-operation and Development (OECD) have collectively shown a declining trend. Meanwhile, the scale of virtual water trade related to material production has expanded rapidly, with developing countries significantly enhancing their position within the global virtual water trade system and emerging as major suppliers. This shift has not only reshaped the global distribution of water resources, but also presented new challenges for future industrial water conservation and coordinated management of water resources across regions.
In response to this trend, the research team urgently calls for global policy actions centered on enhancing water use efficiency. These measures include establishing water efficiency standards for key industries, improving water resource statistics and accounting systems, and accelerating the adoption of water-saving technologies and circular economy practices. These research findings not only provide scientific evidence for the transformation of water-intensive industries, but also offer critical decision-making support for countries to fulfill the Sustainable Development Goal of "significantly improving water efficiency in all sectors and ensuring sustainable access to and supply of freshwater."
