It really seems a vague issue. For bitcoin cannot become a global currency unless there is universal acceptance for it. As of now, of we go by the current status of the bitcoin, we find that bitcoin is more of a source of investment and an asset for the people instead of being used as a medium of exchange or better say currency. Anyhow if bitcoin is universally adopted for the furtherance of the global economy then it will modernize the way things are done and will imbibe many positive changes that are required as of now. It is a decentralized mechanism, so there is more transparency and autonomous operations that will make transactions work in a better manner.