I'll try and avoid jargon as much as possible...and as you consider this, bear in mind that Quentin Smith, one of the brightest atheistic philosophers on the planet,
argues similarly.
If conditions for emergence existed, that means emergence reduces to dependence as emergent properties or entities
depend on the prior conditions. Without such conditions, nothing can emerge. What those conditions are is irrelevant to the point at hand.
An uncaused entity did not emerge nor was it caused by something else. That's a basic fact of definition. If it emerged or had a cause than it would not be uncaused. Speaking of emergent uncaused entities is incoherent.
In the backwards chain of causation one can easily grasp how each link depends on the prior link. Link 0 Can be explained by link -1 as providing the conditions for its existence. And link -1 can be explained by link -2 and so on. As an example, evolution as a process is understood like this. But as each link is dependent on the prior link then we constantly need another explanation for each link we come across. This is the question at hand. Does the chain of links regress infinitely or is there an end to the chain? If we come to an end, how do we understand that first link?
It's actually impossible (though theoretically conceivable) for the chain to extend backwards infinitely for that would mean an infinite past chain would have been traversed by successive addition...ie.....-> Link x -> link y -> link z -> so on all the way to the present. But an infinite past set cannot be traversed by successive addition because it has no starting point and no matter how many links are crossed an infinite number still remain prior to reaching the present. There must be an initial link that is not infinitely behind us. This link cannot be emergent for that just begs the question. It if is emergent then we still haven't found the first link and need to keep going backwards. It cannot be dependent for the same reason. It must be independent. That means it does not depend on any prior conditions for its own existence. It just is and has always existed. It's difficult to conceive of how such a thing can be as our experience is limited to observing finite things. But lack of imagination should not prevent us from acknowledging its necessity.