Construction aggregates - sand, gravel, and crushed rock - are the overlooked raw materials of the Anthropocene. They make up the biggest share of the world’s human-made mass, which outweighed all of Earth’s living biomass in 2020. With a global market valued at around US$ 390 Billion in 2020, aggregates are the world’s most extracted solid materials by mass. Their annual consumption is predicted to double by 2060, exerting further pressure on threatened ecosystems, triggering social conflicts, and fueling concerns over sand shortages.
A drastic problem calls for drastic solutions – truly doing things differently to put aside problems and create pathways to sustainability. The SANDLINKS project has articulated a new perspective on the global sand sustainability debate. Over the last decades, scientists have developed approaches for thinking through how disparate phenomena are connected over space and time (so-called ‘telecouplings’); such as how a change in policy in one place can have unexpected impacts somewhere else. Simultaneously, industrial ecologists have developed methods to quantify and visualize the metabolism of society through inflows of materials and energy from the environment (so-called ‘physical economy’). The first part of the project developed the framework that connects these different branches of sustainability science and shines a new light on the world’s consumption of sand, looking at pathways for preventing and alleviating ‘sand crises’. Instead of looking at components such as geology, logistics, environment, or policy in isolation, this approach looks at the entire sand-supply network to gain a holistic understanding of the stresses on both nature and people across time and space. According to this framework, using sand resources in a way that delivers sustainable prosperity hinges on a good understanding of the physical dimension of sand-supply networks (their backbone), their environmental and socioeconomic impacts across scales and sites (their outcomes), and ultimately on how people decide how, how much, and which materials to use (their brain).
Following this perspective, the project later applied and operationalized the framework of sand-supply networks and the concept of sand mining transitions at case studies in Mexico and China. In these areas, the research shows that ignoring sand-supply networks’ complexity and the strategic value of sand resources can result in unsustainable “solutions”, including problem shifts and unintended consequences of regulations. For instance, a transition from river mining to crushed rock production risks displacing impacts from rivers towards air pollution, water consumption, and biodiversity of karstic systems. In parallel, global synthesis efforts on mining impacts have advanced our understanding of the impacts of sand mining on nature and people and of conflict triggers and development. In particular, this project has been the first to examine the global biodiversity burden associated with mining construction minerals, providing essential information about the magnitude, geography, and profile of this widespread threat.
In conclusion, the SANDLINKS project has been instrumental in building a strong foundation for the research on sand sustainability and has strengthened the knowledge base of the off-site impacts of the construction sector for delivering more detailed and actionable policy insights. The research and outreach activities developed have contributed to increasing awareness of the strategic role of sand resources and to identifying pathways towards a more responsible consumption of the world's sand resources.
