Mark, please don't feel I'm downplaying your concerns about the political parties, I'm not. In fact I share them, probably from a different perspective to you, but certainly agree that the mob in power are pretty useless and Labor hasn't distinguished themselves greatly (mainly because they went to the last election with a pretty good set of policies and an ineffective opposition, and still lost).
My point is that when we decide to sweep the existing democratic process away and go for any kind of dictator, we get a Trump, Bolsonaro, Duterte or some other useless turd who fouls up anything important, like protecting their people from a pandemic for instance.
What would change politics enough to get good action on the climate? Getting rid of the reactionaries that hold both political parties back. Labor and the Greens should be hammering electorates that currently have National Party members sitting. They should be fielding their best people and putting the most effort into seats with the furthest right-leaning Liberal members. Talking about proper electioneering here - lots of volunteers, lots of talking to people, lots of visiting people, organising groups. Intelligent use of big data. Take a ticket from Obama's election run, which was groundbreaking in its grass-roots activism.
If the parties see enough noise about climate change and are put under enough scrutiny as to who is funding them, plus their big business mates actually start moving green, then they will be dragged kicking and screaming into a position of doing what they're supposed to and actually developing policies. Hey who knows, maybe one day they'll actually start competing to be more green than the other lot instead of what they do now.