Time is running out for sand
nature.com
nature.com
Replacing all of the fossil fuel based power generation in the USA could require one million wind turbines according to some sources! My own back of the envelope calculations indicate that we would need close to 500,000 wind turbine to be built. I suppose that additional infrastructure and changes to the power grid for such a massive number of turbines could require addition concrete as well, spelling doom for sand.
[1] http://ontario-wind-resistance.org/2013/04/17/nextera-energy...
I hope that something comparable to concrete can be made out of polymers, glass / ceramics, and steel at a lower CO2 cost.
What would happen if you took the desert sand and used it to replace the river sand? Because you’re now mining and transporting twice, you’ll definitely have higher costs.
They might be. You might find that smoother sand flows more easily, and may be washed away. Certainly the size of grain is important, as smaller grains are carried more easily by the water.
If the intention is simply to displace water, then a better option may be larger rocks. These would eventually be worn down to make more angular sand.
Industry wants the sand because it locks together instead of flowing. Why wouldn’t a river “want” the same thing?
Won’t all the round sand end up at the bottom of a lake or the ocean after a couple of years of seasonal rainstorms?
Whether they are expensive or only effective in certain situations is for the purchaser to decide.
One man's bamboo is another man's carbon fiber, I suoppose.
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
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]
Another excellent reference on physical resource use is Vaclav Smil's Making the Modern World https://www.worldcat.org/title/making-the-modern-world/oclc/...
________________________________
Notes:
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.
http://www.concrete.org.uk/fingertips-nuggets.asp?cmd=displa...
Interestingly, it can be either aggregate or cement, depending on how finely it is ground.
I wonder how hard it would be to convert smooth sand into angular sand. Perhaps a pulsed laser could be used to fracture the grains into angular fragments or something like that.
Not only would being able to use desert sand create an abundant supply, but it'd be beneficial for fighting desertification.
1) wringing its hands about a problem that probably has less of an impact on construction prices than a single NIMBY catching a cold and missing the next zoning meeting
2) suggesting an alternative that would charitably be 1000x the current market clearing price, ignoring the fact that there are probably alternatives at 1.2x, 1.3x, and 1.8x the current price that will kick in long before the 1000x solution would become relevant
.
There are many things that markets handle poorly, but this is not one of them, and the stupidity on display in this comments section is a stark reminder why markets are a good default choice for coordinating human activity.
That change will be when we have cheaper mass power generation than fossil fuels.
The reason this will be transformative is that a lot of problems basically go away when this happens.
Take burning hydrocarbons for energy. We can make hydrocarbons from the atmosphere. It's simple chemistry. It just makes no sense to spend hydrocarbons to make hydrocarbons from air. That's a net loss of power. If wind or solar (both of which have problems with inconsistent power generation, which is an issue of using them for the power grid). Batteries are of course one solution to this. Another is making fuel from air and using it when it's calm or at night or cloudy (respectively) to smooth out power output.
Bringing this back to sand, we can make sand. It's really just ground up stone and we have plenty of stone. Current sand is made from millions of years of erosion by water. But we can make more sand. It's just cost-prohibitive to do so now because energy is too expensive.
On a side note, I honestly don't think humanity can pull back on carbon emissions. Trying to change behaviour is largely going to be fruitless. What will change behaviour is other power sources being cheaper so that's what we need to strive towards.