Reducing demand could go some way minimizing the black market in sand: “We should design our infrastructure to last for longer time periods. And buildings should be designed for multiple uses over time. For example, we should be building a school in a way so that it could later be changed and become a hospital,” says Pascal Peduzzi, head of the Global Change and Vulnerability Unit in the science division of the United Nations. He also says we should focus on retrofitting rather than knocking buildings down and building new ones.
Another way to reduce demand is to have a different supply. Enter recycled construction debris, which can be used in place of sand and may even be available on-site (if a building is being torn down and another rebuilt in its place, say). Worldwide, only about one third of construction debris is recycled, but some proactive countries have significantly upped that number: The Netherlands currently recycles about 90 percent of its construction debris, and Abdulali points to this as a goal worthy of emulation. Additionally, such practices would also cut down on the amount of landfill space needed for this refuse. “Short term, I’d like to get the recycling model going,” says Abdulali. “[In some parts of India,] we do have the policies in place, but we need to force them to be taken seriously,” she says.
Promise also lies in the possibility of enabling desert sand—which is widely available and less destructive to remove—to be used for construction. The team behind a new material, Finite, has devised a novel way to do just that. While master’s students at London’s Royal College of Art, the group behind the breakthrough was looking for a materials challenge: “We found that there was sand being imported to Dubai, which has sand. So, why is it not being used?” explains Carolyn Tam, now at MIT. Once they realized that the sand surrounding Dubai was the wrong kind for making concrete, they wondered if there was an alternative. As they discovered, the answer is yes—they could make concrete from desert sand, and from other materials as well. Their proprietary binding material, “can bind other finds, like quarry waste, byproducts from mining, or even crushed glass,” says Tam. Finite is not just stronger than conventional concrete, it is designed to be biodegradable—and “unlike concrete, it can be melted down and reused,” says Tam.
In some cases, recycled plastics could replace concrete—and could be more durable than our current materials. In Zwolle, Netherlands, the first all-plastic bike path opened in September 2018. Another option is to cut the concrete with less-impactful materials, like earth, bamboo, wood, or straw, according to the United Nations Environment Program.
Demand for sand is increasing—and not just for building new structures. We also need to replace old buildings, since concrete doesn’t last forever. “The scariest notion is that many of these concrete structures are literally crumbling. Most of the world’s concrete is pretty new—a lot of it has been thrown up in the last 20 years, but it’s not being well-maintained. There’s going to be a possible crisis point in 20 to 30 years,” says Beiser.
Reducing the impact of mining will take a multi-pronged approach: recycling, new materials to use in place of sand, sustainable sand mining, reducing demand for buildings, and beach replenishment will go some of the way in making sand use more sustainable. But it’s not going to be simple, considering how easy it is to get sand illegally, how cheap it is (for now)—and how much is needed. Add it to the list of limited resource issues we’ll all be facing in the coming decades: “The problem is also a general problem of the growing consumption of natural resources—that’s a planetary challenge,” says Torres.
We need a radical rethinking of how we use the planet’s limited resources. Says Abdulali, “We have to forget this idea of ‘free natural resources.’ Nothing is free.”