How Is It Possible To Ensure Human Harmony On The Globe?

This really is a biggie. No-one is sure if it can be done, the assumption being that humans are hard-wired for conflict. Certainly, it will take something dramatic and global to effect this change and bring humans together in harmony.

Several possible scenarios spring to mind, most of which are negative.

Firstly, there is the threat of global extinction, either by the hand of Man via global warming, a global natural disaster, or an Earth-colliding asteroid. Just the kind of things to bring humankind together before the end.

Secondly, and perhaps more unlikely, confirmation of an invasion by ETs.

Thirdly, a global religious conversion to one faith, which is as unlikely as an army of space ships from Planet Zog.

Another scenario, and this is not an exhaustive list, is the emergence of a global government. Conspiracy theorists have been grumbling about a secret elite world government for decades now. Maybe there is something in it. Whatever, it will bad news and hardly conducive to human harmony.

On a more positive note, there could be some grounds for thinking a radical shift in human attitudes and the awakening of a new consciousness just might do the trick.

I don't think it will ever be possible to have complete harmony in earth between humans. There never has been and it's probably not possible due to human nature.
As people evolve and hopefully become more enlightened and tolerant of religions and cultural differences perhaps the amount of conflict might decrease over many generations. The idea of a European Union has gone some way towards relaxing tensions in Europe but there are many more countries that aren't part of the European cultural network.
I think that it's unlikely ever to happen in reality.