What are the effects of consciousness, exactly? Is there a procedure to determine whether a given human possesses consciousness as you yourself, do? Is there a procedure to determine whether an AI possesses consciousness as you yourself, do? Is there a way to disprove the solipsist? This is the nub of the problem: there really isn't.
Consciousness does not present itself as just another thing in the world -- at all. It is the unique medium through which you experience everything you have ever experienced. It is the fact that the universe exists from a perspective. You assume that the universe also exists from other perspectives, but there is no objective basis for this belief -- in the sense that there are no phenomena solely attributable to true consciousness.
The fact that we are having this conversation is a measurable effect of consciousness.
Consciousness interacts with the world and causes bodies to do different things. This is a measurable effect. A p-zombie in an unconscious universe is less likely to talk about "qualia" than a conscious being.
Hopefully we will discover some simpler effects to measure in the future, but for know we're stuck with "people sure talk about it a lot for something that doesn't exist...".
I agree that humans discuss consciousness and qualia because these things really exist. So yes, in my philosophical opinion, this is an effect of consciousness on the world. However, first, this phenomenon is not guaranteed to occur with all conscious subjects (MOST humans do NOT discuss these things), and second, the phenomenon can also occur with unconscious subjects (You could be an unconscious program designed to win arguments on the internet). The phenomenon is neither a necessary nor a sufficient indication of Consciousness, and it can't be understood to have any scientific value for any future objective understanding of Consciousness.
My position is even stronger though: I am quite happy imagining honest p-zombies and AIs discussing consciousness, apparently as if they themselves possessed it, but without any internal contradiction. We (you and I) understand each other when we each say "consciousness" and "qualia" but it is only because these concepts have a privileged place in our intellects-- we experience them directly (what's more, they are the stuff of our very experience of anything at all). Now, a p-zombie has no predisposition toward understanding these concepts, because it has no subjective experience of its own. How do I explain these concepts to the p-zombie then, in a manner that will force it to say, "Oh, right, no, I don't have consciousness." I contend it can't be done, that any attempt at a definition can always be misunderstood to apply to objective phenomena of the human brain/mind/person apart from what we know as true consciousness, and this is how a p-zombie or AI will always understand it.
Consciousness does not present itself as just another thing in the world -- at all. It is the unique medium through which you experience everything you have ever experienced. It is the fact that the universe exists from a perspective. You assume that the universe also exists from other perspectives, but there is no objective basis for this belief -- in the sense that there are no phenomena solely attributable to true consciousness.