Who cares what representatives of neoliberal governments and fossil fuel companies have to say about this? The Pope is not the biggest problem at the COP.
I don't think the problem with structures like the church is that it's always an asshole that makes it to the top. It's that there's always a risk that one will make it.
I agree with your criticism about the Catholic Church (I wouldn't call this the biggest problem though), but from what I've read, the current Pope is more of an asset than a liability on this topic.