Sand is used in everything from silicon chips, to toothpaste, to glass, to buildings. It’s our most-used natural resource after water and air. Huge amounts of sand are used in construction— 200 tons to build a house, 3000 tons for a hospital, 30,000 tons for a kilometer of highway— but it turns out that it has to be the right kind of sand. This has led, incredibly, to a situation in which 3,500 Australian companies now export sand to the Middle East.

That’s right. Cities that are located on the edge of deserts are importing their sand from the Indian Ocean and Pacific, just like they’re importing their labor. Pretty mind-boggling.

Savina Venkova, a former intern at the Earth Policy Institute and future sustainable development scholar, writes about this strange situation, and its serious environmental consequences.