I can't read the article, but in my understanding, sand for concrete is what might be scarce. Because it has to have particles with the right degree of sharp co

I can't read the article, but in my understanding, sand for concrete is what might be scarce. Because it has to have particles with the right degree of sharp corners. (IIRC, the Saudis import this from Australia or something, because their wind-blown sand is too round.) But glass is much easier.