I think consciousness is going to turn out to be very challenging to define rigorously enough that we can test for its presence or absence. Emergent or not, the question is how do you determine when it has emerged? Is it a quantity or an attribute? Discrete or continuous? Does it have a finite or infinite range?

We can all agree on what color something is, but we can’t describe the color a priori, only by example. I think consciousness may be a similar phenomenon and the only test is by shared experience. If so then we are in deep trouble because we will not be able to anticipate when a system becomes conscious.