Its issue is too important to be left to banks instead of being under democratic control.
There are well known problems with resource based currencies and no real reason why a currency should be resource based to be credible.
All currency is a token of labour productivity, present or future.
The trillions of US$ debt at present exceeds any possible future US productivity many times.
For a sustainable economy we need to return to the idea of money as a medium of exchange, not as a commodity which can be magically increased in a computer unsupported by work.
The central bank should be the only issuer of money and the whole concept of interest and charges on the economy by the financial sector needs to be revisited.
Their share of GDP has grown rapidly since the withdrawal of restrictions on them since the 70′s (80′s in NZ) without any corresponding benefits to society as a whole.
Instead we are all supposed to have austerity imposed on us to pay their gambling losses.