As jkpate has suggested, if you're trying to find the underlying cause of an emergent phenomenon, you're failing to appreciate what the word means. Emergent systems have properties that can neither be reduced nor displaced to something else. That's the entire point.
I have no idea why an analysis of causality "at a level of human understanding" should require a simple vector between cause and effect. After all, human understanding has been engaged with far more interesting material relationships for millennia now, as far back as we can trace. If you want to stipulate for yourself that "why" has no place outside of determined causation, that's your choice to make of course, but you're going against a few centuries of very well-established convention for the word in epistemology and the philosophy of science.
