There are new calls for the sustainability of global sand supplies as researchers take a holistic view of how humans use sand throughout the supply chain.
A research paper – titled ‘Sustainability of the global sand system in the Anthropocene’ – has been published in One Earth, a peer-reviewed journal on global environmental change and sustainability science. In the paper, researchers from the Michigan State University’s (MSU) Centre for Systems Integration and Sustainability and Belgium’s Université catholique de Louvain examine the sustainability implications of overexploitation of sand, which is a key ingredient in concrete, asphalt and glass.
They argue that in 2020 the sum of ‘manmade’ objects (anthropogenic mass) for the first time exceeded living things on Earth (global biomass), with the largest share of the former coming from construction aggregates (sand, gravel and crushed rock).
This momentous occasion, they add, underlines just how much material we need to continue developing our built environment.
Aurora Torres, the lead author on the paper, told The Eurasia Review this focus on sustainable production was important.
“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,” Torres said.
“As with climate change, there is not a single solution but multiple entry points for more sustainable consumption.”
As such, the researchers have suggested a universal understanding of the construction supply chain is required to effectively confront the issue. They contend “knowledge is compartmentalised across disciplines”, disallowing the entire supply network from functioning as effectively as the human race needs it to.
“Here, we present a new perspective on global sand sustainability that shifts the focus from solely evaluating local impacts of sand mining to understanding the entire sand supply network (SSN) of a region as a coupled human-natural system,” the authors write in the preface.
With a general sense of humanitarianism, the paper shows most concern for the strength of global supply chains and the satisfaction of societal needs.
Principal at Ecoroc Consulting Engineers Dugald Gray told Quarry that the ongoing replacement of natural sand with hard rock sand will continue its upwards trend for Australia as a whole, but it will come with its own set of hurdles.
Ecoroc, in conjunction with RW Corkery & Co, has in recent years been involved with a study of the raw construction materials needs of the Greater Sydney Region on behalf of the Mining, Exploration and Geoscience division of the Department of Regional New South Wales.
“If hard rock is to progressively supplant natural sand sources (within this century it is probably inevitable at a global scale at least), then important economic matters of transport costs and a reduced diversity of suppliers also come to the fore,” Gray said.
“Even in Australia, many natural sand deposits, particularly across the regions are worked by smaller firms, not the multinationals.
“If the societal choice is ultimately to dispense with these sources of natural sand supply by replacing them with rock sources, then we must expect less competition, choice and convenience for the community as a whole.”
Not only will the transition to hard rock sand sources become a barrier for entry to smaller businesses, but the technical demands of the undertaking can be underestimated, according to Gray.
“Nature has done much of the work in value-adding natural sand – reducing it down to its particulate state, shaping it and removing much of the weaker contaminants,” Gray said. “[This is] not so with crushed rock fines.
“Any audit of the sustainability merits of natural sand versus manufactured sand must also address the embodied energy issue – otherwise the sustainability equation is incomplete.”
Gray believes that while Australia remains safe from the “global [sand] crisis” for now, it may be best to aid in the crisis lest the country finds itself unprepared for a shift in global demands.
“The exporting of bulk sand to Asia for use as construction aggregates presents as one such opportunity. However, I think there is a risk of Australia adopting a ‘head in the sand’ mindset in response to the global shortage of natural sand,” Gray said. “This would be myopic. It is not inconceivable, that like illegal fishing, hungry eyes will turn to our continent in the future as the global sand shortage intensifies.
“We should keep the issue clearly on our national radar, do our bit to help alleviate the global sand shortfall, but not assume our sand resources [for use as construction aggregates] are ubiquitous. It would seem that very assumption has led to the global sand crisis.”
The joint MSU Centre for Systems Integration and Sustainability/Université catholique de Louvain paper can be found on the Science Direct website.