I think our main problem is the huge electricity expense induced by mining and its noxious effect on the climate. This is, to my mind, the only serious argument against Bitcoin.
Alleviating the electricity expense should be one of our priorities. If we do not do it for the sake of the Earth (which we really should) we should at least do it selfishly because governments will not tolerate this forever and they will be right. The more the exchange rate increases, the worse it gets, of course.
Some solutions exist though: first there is proof-of-stake, of course. This technology may be too young to be deemed reliable enough but we should at least start considering it.
If we do not like proof-of-stake I think we could drammatically decrease the electricity expense by stopping monetary creation now. Nowdays Bitcoin is famous enough to remain secure even if miners earned transaction fees only. And if as a whole there are 16.5 M coins instead of 21 M, this does not make much of a difference. That is even good for holders. To make miners agree with that solution, they must be compensated for their lost income. More precisely, active miners must be compensated because they have already bought ASICs. Futures miners do not need to be compensated. Since mining is a competitive industry, future miners will make no profit on average, whatever the reward scheme. To compensate active miners we could decide that the next 2016 blocks yield, say, 100 new coins and then 0 forever. Everybody would win and the Earth above all!
There are probably many other solutions and I wish the community cared a little more about this fundamental issue.
Hi there benjiw! Yes indeed, mining bitcoin need a lot of power or energy which mostly came from a diesel power plant. Other have utilized nuclear power plant which is also hazardous to the environment. But recently there are a lot of miners that are transitioning from coal, diesel or nuc to a renewable energy. I am talking about the solar and wind energy. The initial investment could be much higher than the common source or electricity but it would be more rewarding after three or four years. Those miners who use renewable energy could have much higher income compared to those who are on the grid. Additionally, those miners help to prevent global warming.