Consider all emergent phenomena that you know of. Let's say: stock market prices, ant hills, biological organisms, ecosystems, etc, etc. What all these have in common, is that they are too complex to explain in terms of individual interactions, but you can point at the individual interaction. We know that financial markets are made of transactions, of that biological organisms are made of molecular interactions, but they are too complex for us to reason in such terms.

With consciousness, the emergentists are not capable of pointing at the first principle, or building block. For me, the only coherent way to be an emergentist on consciousness is to also be a panpsychist: everything is conscious to a degree, it's just a brute fact of nature (such as, let's say, the fundamental forces).

Maybe this is the case, but I would not bet on that.

Consciousness is a phonomenon unlike any other, in the sense that scientist who study it are studying it from the inside. Science is something that happens 100% within human consciousness. This is why I suspect that it is a phenomenon that is beyond the reach of science. It could even be impossible to explain. There is no reason to assume that we can solve all mysteries.