Consciousness is something that we each notice about ourselves.
(Or rather, "consciousness" is a philosopher's way of talking about that thing which we notice about ourselves that we can't directly notice about others, though we infer them about others.)
It seems to me that part of the question, then, is "What is noticing?"
In Zombies! Zombies? Eliezer mentions that one aspect of consciousness is that it can causally affect the real world, e.g. cause you to say "I feel conscious right now", or result in me typing out these words.
Even if a generally accepted mechanism of consciousness has not been found yet are there any tentative explanations for this "can change world" property? Googling around I was unable to find anything (although Zombies are certainly popular).
I had an idea of how this might work, but just wanted to see if it was worth the effort of writing.