Digging up solutions for a looming global sand crisis
Sand is the world's most extracted resource, and that's a problem, say researchers
In the year 2020, we passed an alarming milestone — Earth is now covered in more man-made mass than natural biomass. Much of this material is built using sand, and researchers say we are facing a looming global sand crisis as a result.
"Every year we are now extracting more than 50 billion tons of sand, gravel and crushed rock, for making the concrete for our houses, the asphalt of our roads," Aurora Torres told Quirks & Quarks host Bob McDonald. "And silica sand is also used for making the screens in our laptops, or even for the solar panels that are fundamental now for this transition to renewable energy. So it plays a very big role in our lives."
In 2017, Torres was part of an international group of scientists who published a paper in the journal Science shining a light on the overexploitation of sand. In that paper, they detailed how the world's voracious appetite for sand — expected to double by the year 2060 — was damaging the environment, and triggering social conflicts.
Now, the group has published a second paper, in the journal One Earth, looking at potential solutions to this crisis.
"As it happens with climate change, there is not just one action that we have to take, but many different actions on different levels," said Torres.
Sand mining is destroying beaches, hurting biodiversity
Torres is a postdoctoral researcher at Michigan State University and the Catholic University of Louvain in Belgium. She said that sand is considered to be a "common-pool" resource, meaning it is freely available and because of that, the industry is hard to monitor and regulate.
A common refrain is that the world will run out of sand, but Torres doesn't feel that is where the troubles lie.
"I'm personally not that much concerned about running out of sand, about not having a grain of sand in the world, because in geological terms, sand and gravel are abundant," she said.
However, she adds that there are local shortages, in areas where sand mines have been overexploited. As the global demand increases, beaches and entire islands have disappeared and riverbanks have collapsed.
Adding to the problem is that all sand is not made the same. The sand found in abundance in deserts around the world is actually unsuitable for use in construction aggregates because desert sand grains are too round to stick together well to make good concrete. The best sand is found underwater, like at the bottoms of lakes and rivers, as well as on beaches and riverbanks.
Because sand plays an important role in the ecosystem, any reduction in sand supply can have huge impacts for both animals and humans — from coastal erosion to habitat destruction to the spread of invasive species.
"There are so many species that rely on the sand in dunes or in rivers. They are nesting habitats for turtles," said Torres. "At the same time, they are also providers of ecosystem services for people. They are critical for filtering groundwater, for protecting areas from flooding and also for food production."
Black market "sand mafias" have also popped up around the world to meet demand, illegally mining sand often in the dark of night, which may exploit communities and regions that are already vulnerable.
Reduce, reuse, recycle — and regulate the industry
In their recent paper, Torres and her colleagues looked at the entire global sand supply network and applied multiple branches of sustainability science to understand the issues for nature and humans.
An important first step, she said, is that the industry needs to do a better job managing sand resources, and regulating along the entire supply chain to allow for monitoring environmental and social impacts.
She adds that it is also critical to reduce the amount of sand that we're using — either by making artificial sand using crushed rocks, by using our current buildings more intensively, or by recycling available materials after buildings are demolished.
"For example, extending the lifetime of buildings, or building for disassembly. So already thinking when the moment you are building something, on how you could in the future maximize the use of the components of that structure," she said.
She also points to other initiatives, such as a recent movement in New Zealand to turn beer bottles into sand.
Ultimately, Torres said that people need to curb their consumption of materials that use sand.
"The most influential material efficiency strategies are going to be the ones that are focused on social aspects," she said.
"All the trends right now are towards increasing floor area per capita, increasing urban sprawl, that increases the material demand for [sand]. So this is something that we need to reverse if we really want to have an impact on the use of these resources."
Produced and written by Amanda Buckiewicz.