What the philosophers call "qualia" certainly exist, but I find it likely that they are simply intermediate symbolic representations in our wetware of the signal inputs our senses are receiving (or remember receiving) and often have added emotive connotations based upon our unique experiences.

I have agreement with those who suggest that "consciousness" as we internally perceive and externally discuss it is largely illusion.  Self awareness is a triviality as, for example, modern computers balancing file buffers and paging space. The illusion is that we are the abstraction of ourselves that we discuss when we talk about "consciousness".   We are the wetware symbol manipulations processes and encoded knowledge that creates that symbolic "I" and related abstractions, not the symbol itself.

Offered for devastating critique and criticism:

Consciousness is the qualitative ability of an entity to reasonably predict the consequential changes in its internal states in response to its own options and ability to interact with its environment.

Yes (IMO) animals have varying degrees of consciousness.  We're unique in scope and scale, not in kind.

I think that formal statement pretty close.   Notice that the scale of intelligence is embodied in the predictive quality of the environmental interaction and the possible complexity of the internal state.  But also notice that there is absolutely no reference to motivation for attaining internal states.  Once an AI exists capable of human level consciousness its motivation will be a matter of programming.

Consciousness itself once we learn to define and manipulate the symbols (inputs) at a sufficient level of complexity and abstraction (and the real trick is across varying levels of abstraction) will not be hard to build into a machine.   Then comes the prolonged difficult work of amassing and encoding the equivalent of a lifetime's experience into a machine which can manipulate them in a manner sufficiently lifelike and programming "motivations" as changes in program state which are sufficiently humanlike in relating that encoded data to new inputs (and encoding them as new "experience") well enough to "fool" an observer.

But note well that while such an amalgam of symbol manipulation and encoded knowledge exists, and must as per the Turing Test be considered "intelligent", we are faced with the difficulty of deciding whether equally complex processes are "intelligent".  Is consciousness necessary for "intelligence" at all?

Miscellaneous anecdotes regarding consciousness:

I remember the emotional shock of coming into various stages of human consciousness.

I remember being very young (3 or 4) and running over a neighbor girl's foot with a tricycle ... and being startled by her crying and then realizing (but not in words) that I wouldn't like having my foot run over either.

I remember wondering (about age 5) why adults always went around in in male and female pairs (hey this was a small town in the early 60's) and wondering if that would happen to me (it did, of course, but I was quite puzzled at the time but the puzzlement was so strong it is the first memory I have of thinking of myself other than in the immediate present).

About the same time (shortly after my great-grandmother died) I remember thinking and asking questions about death and realized that it probably applied to me too.   Very interestingly I noticed that same crisis of consciousness in my oldest daughter when she was about the same age - but no one near her had died.

I don't have distinct memories of latter changes but I do remember noticing somewhere around 10 or 11 that I spent more time thinking about what I wanted than how I immediately felt.

And apropos of the season, I became aware of the Christmas problem probably in the early pre-teens:  that what you wanted to get, even if you got it, was far less exciting after you had it for a few days.

Miscellaneous quibbles with this thread:

No the AI program as algorithm is not "conscious",   Nor is the algorithm + the encoded data.  Nor is the computer(s) that will run it.   But algorithm embedded in the process running on the computer is.   My computer is not a word processor.   The shiny disk that says "Microsoft Office" is not a word processor.   One of the programs (and associated libraries) encoded on that disk when loaded and while actively running on my computer is a word processor; it ceases to be such when I stop it.   Where is the problem here?