A few miles up the Sermilik Fjord in southwestern Greenland, the water has abruptly turned milky, a sign that it is loaded with suspended silt, sand and other sediment.
It is this material — carried here in a constant plume of meltwater from the Sermeq glacier at the head of the fjord — that Mette Bendixen, a Danish scientist at the University of Colorado, has come to see. As their research boat moves farther into the murky water, she and several colleagues climb into a rubber dinghy to take samples.
Dr. Bendixen, a geomorphologist, is here to investigate an idea, one that she initially ran by colleagues to make sure it wasn’t crazy: Could this island, population 57,000, become a provider of sand to billions of people?
Sand for eroded beaches, potentially from the Rockaways to the Riviera. Sand to be used as bedding for pipes, cables and other underground infrastructure. Mostly, though, sand for concrete, to build the houses, highways and harbors of a growing world.
The world makes a lot of concrete, more than 10 billion tons a year, and is poised to make much more for a population that is forecast to grow by more than 25 percent by 2050. That makes sand, which is about 40 percent of concrete by weight, one of the most-used commodities in the world, and one that is becoming harder to come by in some regions.
For the rest of this article: https://www.nytimes.com/interactive/2019/07/01/climate/greenland-glacier-melting-sand.html