Decentralization of AI is going to be must in the future. Just imagine, if someone programmed an AI system to control global warming and with its reasoning it ultimately finds out that we humans are the main culprit..................hahaha.
Decentralization of power is the only way I suppose.
I don't know if that problem will be solved by blockchain :) A super AI will transcend all levels of human thinking and comprehension... so that's an altogether different dimension in my opinion and we are far away from a solution