What is a good future money system? This question could be written about for thousands of pages, listing a multitude of possible ideas with their negative and positive side effects.
Sure, alternate currencies, micro loans and simple bartering all assist in ensuring that economies stay (semi) functional and hopefully stable; but to truly solve any problem one must view the entirety of the scenario in question.
This entirety would be the monetary system that governs most of the world: Capitalism. Capitalism has negative and positive effects. Amongst other things it encourages hard work, creativity, competition and ingenuity. Negatively it is an uneven system based on the idea that a certain amount of a population must be poor and relatively uneducated in order for the system to succeed. It is crucial that the capitalist system has unskilled labourers to carry out small jobs on production lines, cleaning, maintaining sanitation and various other unskilled positions.
A small example would be a gardening service that needs people with little skills (who can mow lawns and pick up garden waste) who are willing to work for a small wage. Capitalism relies on these people who desperately need the little they earn to survive and provide for their families.
Of course we cannot simply eliminate capitalism, but we need to bring about crucial reforms if we are to ensure future economic stability which will allow our current monetary system to endure.
We do have unions, civil rights groups and political parties fighting for workers rights and for people at the bottom of the economic ladder, but greater reforms are needed. Reforms to the ideology which capitalism is based upon: Profit. Under capitalism profit is created by paying workers less than what is earned by an industry. The surplus earnings are the profit which is partly divided up by shareholders and partly re-invested to further grow the company or industry.
A system must be devised which places less interest in profit and more in human capital. Human capital should focus on looking after the poor and low income workers, providing schools, clinics, hospitals and other much needed facilities to areas which are highly underprivileged.
By reforming the entire system from within and eliminating much greed from the process, the global economic system would become far more stable. Of course this is highly idealistic as the people with the most capital would be needed to bring about most of the change, but in the long term this must become the future of global economics, or quite simply the future money system is doomed for failure.