this is larry gallagher, both landmark u. n. report and 2019 on solving san shortages. now, scientists always complained any more data, but when it comes to san, the really have no idea. it is the 2nd most consumed disorder after washer, from the parents, and we don't know where it's coming from and what the impact of that would then that's the nature of the problem. but what they do, no worries them. research isn't 2017 model that global demand. sand is growing much faster than what's easily available. the world would need to make more sand, find new sources of it. oh, just use less. otherwise, it will run out. this is a big problem because sound of the fundamental building block of modern life, sand used in concrete, has been essential to the global construction b. as people in emerging economies move to cities and people around the world are building more and more. india has become the 2nd biggest cement producer. i've lost half century. singapore has built artificial island that have increased its land mass by a quarter. and it did this with massive amounts of sand