But I'm interested in the maximum supply of gold. It is a finite resource and can get exhausted like most mineral resources.
I tried to find the answer to this, and was surprised with what I found:
Goldman Sachs analyst Eugene King took a stab at answering this question last year, estimating we have only 20 years of known mineable reserves of gold.
Source:
https://www.equities.com/news/how-much-gold-is-really-left-to-be-mined (Article from 2016)
This source also says something similar:
The concern about remaining extractable gold is based on the fact that annual gold mining production is running at over 3200 tonnes per annum (e.g. 3247 tonnes in 2017 according to GFMS), while various metal and geological consultancy estimates put the amount of remaining extractable gold reserves worldwide in the region of 55,000 tonnes. In other words, at current rates of extraction, according to these estimates, known gold reserves worldwide would be depleted in about 17 years.
Source:
https://www.bullionstar.com/blogs/ronan-manly/annual-mine-supply-gold-matter/ (Article from 2018)
So it seems that somewhere around 2035, there will be an end to gold mining, at lest when it comes to conventional methods of mining. By that time we may find other methods, or advance in space exploration, who knows.
How much gold has been mined to date?
Estimates range from 155,244 tonnes, marginally less than the GFMS figure, to about 16 times that amount - 2.5 million tonnes.
Source:
https://www.bbc.com/news/magazine-21969100So, now the math isn't so hard, depending on the number we accept as the actual number of available, already mined gold.
IMO, central banks should switch to bitcoin. There are theories that gold's scarcity was something that made gold so desirable and precious in the first place, and not the other way around. Now that we have bitcoin, do we really need gold any more?