I think this is sufficiently important that it needs a thread of its own, and maybe it should end up being stickied.It should be fairly obvious that we need a medium of exchange and a representation of wealth. Bartering is simply not how we can run the planet of 7bn people this Wednesday evening. The question then is what shall we ALL agree on as a medium of exchange / representation of wealth? This is tricky, we can't use leaves as the good folk of the B-Ark suggested. Historically we have used anything that is scarce, long lasting, can't be faked etc... unfortunately these characteristics correlate well with precious metals like gold, also also gemstones etc. Land is also fairly good as a store of wealth for similar reasons - however, it makes a rubbish medium of exchange.
Arguably a lot of our problems owe their origins to when we stopped using these scarce, long lasting, hard to fake objects and instead moved to a system only slightly better than leaves. Slightly better as we trusted only a few folk to actually grow and hand out the leaves in a controlled way. Well that system is now looking rather dodgy. It's perfectly logical to look back at those tried and tested representations of wealth.
The big dangerous holes and poisonous methods are certainly a negative side effect but we absolutely have no better idea this evening of how to solve this very real problem of how to represent wealth.
In the thread it came from, we ended up having a rather pointless ethical argument about the ecological damage caused by mining, specifically mining for gold. While I don't want to underplay the importance of any sort of ecological damage, I think the issue of gold mining is at best peripheral and arguably irrelevant.
It's arguably irrelevant for three reasons:
Firstly, most of the gold ever mined is still owned by some person or organisation as bullion/jewelry, and therefore it is not actually necessary to mine any more of it, because we could just use the gold already in existence (price-adjusted, naturally.)
Secondly, most of the new gold coming onto the market is a by-product of mining for other metals, especially copper and silver, and there's no way that humans are going to stop mining for these any time soon, because both of them are too useful as industrial metals.
Thirdly, regardless of what monetary system is in place, people are always going to want gold for other reasons (it's very pretty, after all), and gold mining is going to continue for this reason.
So hopefully we can avoid getting sidetracked too much on that debate and try to address the question Chris asked. We need a medium of exchange and a means of storing wealth. The fiat money system is doomed (I hope we can all agree on that one), and while a gold-based system may have worked reasonably well in the past, there is no reason to assume it is the best way forward, because there are so many major ways in which the world we are heading towards is different to the world that existed last time there was a proper gold-based monetary system (total number of people, new era of declining availability of natural resources (especially energy-related), globalised nature of economy, electronic/instant nature of financial transactions, and all the rest.)
These questions are precisely the sort that this forum was put here to try to find answers to, I think.