Hungry for sand: Huge demand wreaks havoc on Earth

Sand is embedded in the concrete of nearly all the world’s buildings and roads. The glass in windows, laptops and phone screens and now, COVID-19 vaccine vials. While we are swimming in sand, ironically, our consumption makes us hungry for more.   

Four years ago, an international group of scientists, including two from Michigan State University, called attention to a looming global sand crisis. An overexploitation of sand, a key ingredient of concrete, asphalt and glass, was damaging the environment, endangering communities and triggering social conflicts.   

Now, scientists led by research associate Aurora Torres shine a new light on the sustainability implications of the world’s demand for sand. In the journal One Earth, published online May 21, the team proposes different solutions for meeting these challenges.    

“With this paper, we look forward towards what we need to do as a society if we want to promote a sustainable consumption on global sand resources,” said Torres, part of MSU’s Center for Systems Integration and Sustainability, or CSIS, and the Université Catholique de Louvain in Belgium. “A drastic problem calls for drastic solutions — truly doing this differently to put aside problems and create pathways to sustainability.”   

The unexamined true costs of sand — broadly, construction aggregates production — has spurred the scientists to call for a stronger focus on understanding the physical dimension of sand use and extraction. They also suggest new ways to achieve economic and environmental justice.   

The authors of “Sustainability of the global sand system in the Anthropocene” call for a new way of looking at and understanding the interlinkages of sand supply and demand to reduce negative impacts such as depleting natural environments and creating human conflict. Collaborating across the research disciplines made it possible to fit the puzzle pieces into a full picture. Rather than focusing on single sand extraction sites like many studies before them, they take a broad look at the physical and socio-environmental dimensions of sand supply networks  — linking extraction, processing, distribution, economics, policy — to gain an in-depth understanding of the stresses on both nature and people. 

The novelty of the sand supply network approach is the integration of material flow analysis with the telecoupling framework to provide a more robust and holistic perspective on the sand system across different spatio-temporal scales. It allows for understanding and quantifying socioeconomic and environmental interactions from mining sites to consumption sites — such as cities — and spillover systems such as the transport corridors or rural landfills where the mining and construction waste piles up.   

“Simple views cannot solve complex sustainability challenges,” said co-author Jianguo “Jack” Liu, director of MSU-CSIS. “New ways like the telecoupling framework help untangle and embrace the complexity of global sand challenges and point the way toward effective solutions.” 

In addition, the authors highlight that robust strategies for managing sand resources depend on a solid understanding of the construction aggregates cycle. As Mark Simoni from the Geological Survey of Norway put it, “The physical system is key for linking local impacts of natural resource extraction to global development trends — we have to map how construction material demand and supply evolve over space and time to inform stakeholder decisions and policymaking.”  

This requires quantifying the geological deposits, flows and accumulation of construction aggregates within a region, including both natural raw material sources and alternatives, and it can be used to assess how long resources will last and how the entire supply system can be optimized to reduce negative impacts of sand mining and make use of substitute materials.  

For example, they said, we need to think about construction aggregates beyond excavating deposits of sand and gravel. Blasting and crushing rocks also produces ‘‘artificial’’ sand and gravel of similar or even higher quality, and is a major export commodity for instance for Norway. Indeed, crushed rock has already become the main source of aggregates in countries like the U.S., China or in Europe. 

With demand for construction aggregates predicted to double in the next decades the sustainability challenge is daunting. Understanding how sand-supply networks work is relevant not only for assessing their full impacts, but also for identifying leverage points for sustainability.  

“As with climate change, there is not a single solution but multiple entry points for more sustainable consumption.” Torres said. Possible pathways include reducing material demand per capita, promoting compact urban development for more efficient material use, reducing reliance on natural deposits by developing the market and technologies for secondary materials such as construction and demolition waste and, when mining natural deposits is necessary, identifying the mining sources and production methods that minimize impacts for nature and people. 

In addition to Torres and Liu, the paper was written by Mark Simoni and Daniel B. Müller of the Norwegian University of Science and Technology in Trondheim, Norway; Jakob Keiding of the Geological Survey of Denmark and Greenland in København, Denmark; Sophus zu Ermgassen of the University of Kent in Canterbury, UK; Jochen Jaeger of Concordia University in Montreal, Canada; Marten Winter at the German Centre for Integrative Biodiversity Research in Leipzig, Germany; and Eric F. Lambin at Stanford University in Stanford, CA. 

The work was funded by the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement (846474) through the SANDLINKS project. 

This story was edited and appears in its original form on the Center for Systems Integration and Sustainability website.