Their data supposedly comes from "Sverdrup, H. U., Koca, D. & Schlyter, P. BioPhys. Econ. Res. Qual.2, 8 (2017)" Vague reference, no title.
This seems to be "BioPhysical Economics and Resource Quality", which is a Springer publication. Here's the actual article, "A Simple System Dynamics Model for the Global Production Rate of Sand, Gravel, Crushed Rock and Stone, Market Prices and Long-Term Supply Embedded into the WORLD6 Model", by Harald U. Sverdrup and others.[1] It's not even paywalled. Some quotes:
"The resources of sand and gravel are estimated at 12 trillion ton each, another 125 trillion tons of rock is suitable for crushing to sand and gravel and at least 42 trillion ton of quality stone is available for production of cut stone."
"Sand, gravel and stone materials use in construction amounts to about 47–59 billion tons per year"
"Sand and gravel show plateau behaviour and reach their maximum production rate in 2060–2070. The reason for the slight peak towards a plateau behaviour is partly driven by an expected population decline and increasing prices for sand and gravel, limiting demand. Assuming business-as-usual conditions rates remain at that level for centuries."
So we have another 1000-2000 years of sand left? Did anyone read the references?
Incidentally, if you are in Silicon Valley and need base rock, there's a place on Seaport Boulevard in Redwood City where you can get free concrete, ground into gravel-sized chunks. They charge for concrete disposal; the product is free.
Heavy structural materials tend strongly toward local utilisation as transport costs are so prohibitive (water transport possibly excepted). Concrete companies are the canonical anti-monopoly-tending industrial sector example in many econ texts.[1]
So your objection is somewhat like claiming oxygen starvation by fire is impossible since the atmosphere as a whole is 20% oxygen. It's what's near you that matters, and the local impacts of sand and gravel mining are often severe. As the Nature article notes:
Desert sand grains are too smooth to be useful, and most of the angular sand that is suitable for industry comes from rivers (less than 1% of the world’s land).
Riparian ecosystems are generally the most productive of terrestrial (vs. marine) zones, and activities at one point on a river will have major impacts downstream and even offshore.[2]
1. Which suggests strongly that frictions may be the most effective antimonopoly measures, and low-friction sectors tend strongly toward monopoly.
2. E.g., the Mississippi River dead zone in the Gulf of Mexico, much of which is a consequence of Chicago toilets, 2000km north. As well as ag activity along the Mississippi-Missouri-Ohio-Arkansas-Red river system.
This seems to be "BioPhysical Economics and Resource Quality", which is a Springer publication. Here's the actual article, "A Simple System Dynamics Model for the Global Production Rate of Sand, Gravel, Crushed Rock and Stone, Market Prices and Long-Term Supply Embedded into the WORLD6 Model", by Harald U. Sverdrup and others.[1] It's not even paywalled. Some quotes:
"The resources of sand and gravel are estimated at 12 trillion ton each, another 125 trillion tons of rock is suitable for crushing to sand and gravel and at least 42 trillion ton of quality stone is available for production of cut stone."
"Sand, gravel and stone materials use in construction amounts to about 47–59 billion tons per year"
"Sand and gravel show plateau behaviour and reach their maximum production rate in 2060–2070. The reason for the slight peak towards a plateau behaviour is partly driven by an expected population decline and increasing prices for sand and gravel, limiting demand. Assuming business-as-usual conditions rates remain at that level for centuries."
So we have another 1000-2000 years of sand left? Did anyone read the references?
Incidentally, if you are in Silicon Valley and need base rock, there's a place on Seaport Boulevard in Redwood City where you can get free concrete, ground into gravel-sized chunks. They charge for concrete disposal; the product is free.
[1] https://link.springer.com/article/10.1007/s41247-017-0023-2