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A combination of harvesting and coastal erosion continues to deplete the world of its second most used natural resource: sand

portrait graphics illustration of an hourglass filled with sand and surrounded by greenery and a red hibiscus against a tan-colored background

It’s hard to imagine the world running out of the little white particles making up Hawaii’s beaches, but it’s true, said Dr. Spencer Ingley, assistant professor in the Faculty of Sciences.

“A lot of shore is lost along the coastline due to erosion,” said Ingley. “Sand is also mined from all over the place for use in construction projects. … Sand is moving quite a lot, both with the help of humans and naturally.”

He said as the world grows more urban, the Earth’s sand reserves grow smaller, and just behind water, sand is the most-used commodity in the world.

“Sand does seem like a limitless resource, but it’s not,” Ingley said. He said there is a high demand for sand to create products used every day, from glass and silicon microchips to concrete.

Using up the sand

In a Business Insider article, Rob Ludacer says most of the sand the world consumes is used to make concrete, which is made of 75 percent sand. This means the more cities built with concrete, the more “marine sand” is taken from the bottom of rivers, lakes and oceans, he explains.

In his CNBC article, Sam Meredith writes although it is difficult to measure the amount of sand used every year, scientists estimate 4.1 billion tons of cement is produced annually worldwide. This means the world uses 40 to 50 billion tons of sand annually, explains Meredith.

Ingley said, “As the human population has grown exponentially, so has our demand for sand. We’re living bigger and more complex lives than ever before, and this is putting a huge strain on all of our natural resources, including the oft-forgotten sand.”

Honolulu built with Maui’s sand

Adriane Corwin says in her Maui News article that sand mining is a big deal in Maui, where the island has a unique Pu’u One (hill of sand) dune system. She explains the sand from Maui’s dunes was sought after in the 1980s because it produces high-quality concrete.

By 2006, she says 70 percent of Maui’s dune sand was shipped to Oahu, making up 2.5 million tons of sand to build the urban metropolis of Honolulu.

A Khon2 article states in 2018, Maui county Mayor Alan Arakawa, called for a six-month ban on sand mining in Maui. However, the Maui sand dune debate continues today with no permanent action taken by the government, the article says.

Bye-bye, beach

The Sydney Morning Herald reports, “Waikiki beach has shrunk by about 30 cm a year over the past five decades.”

Ingley said beach erosion is partly driven by a rising sea level and more frequent and stronger storms. “Storm surge erodes the coastline quickly, causing our beaches to retreat. Because we’ve built along so much of the coastline, there isn’t anywhere for the beach to retreat to,” he said.

On the Hawaii News Now website, Samie Solina explains this year, the Department of Land and Natural Resources and the Waikiki Beach Special Improvement District teamed up to restore 24,000 cubic yards of sand to the Waikiki beach. Solina explains the team does this by dredging up sand from the bottom of the seashore and pumping it onto the beach.

Ludacer acknowledges the problems associated with this solution. He says dredging up sand disturbs habitats of ocean floor microorganisms. In addition, the sand dredged up is quickly replaced again with sand from the seashore anyway.

Ingley said a shortage of sand affects Laie the same way it does the rest of the world. Ocean levels erode the coast, so he said beaches like Hukilau will lose their sand, much like Waikiki and other beaches in Hawaii. As the sand depletes, the supply of building materials made with sand will decrease, driving their prices up, he explained.

Save the sand

Ingley gives students this advice to help save the sand, “The best thing [people] can do is avoid trampling coastal vegetation and get involved in local restoration projects that might help bolster the health and strength of [the] coastlines.”

He discouraged panicking about the shortage, but said, “We should definitely be concerned about this issue and do what we can to help. First and foremost, we should consume less. The more we consume, the more natural resources we use.”

Ingley explained why he believes it is the responsibility of people to preserve the Earth’s resources. “I think [people] have a divine mandate to care for natural resources. ... There is a lot we can do as individuals, as a church, and as a whole population to decrease use of natural resources and foster the recovery of resources through the appropriate restoration projects.” •