Prime Minister Scott Morrison and Energy Minister Angus Taylor (Image: AAP/Mick Tsikas)

If nothing else, the 6th Intergovernmental Panel on Climate Change (IPCC) report should put an end to the nonsense from Canberra's political journalists that "net zero by 2050" is in some way a meaningful benchmark of effective climate action.

The world now faces reaching 1.5 degrees of warming well before 2040 under all scenarios modelled by the IPCC working group, and two degrees between 2041-60 under three of them. Even under the second best scenario, we're headed toward two degrees by the end of the century. For a country that, like so many others, is already suffering dramatic consequences from global heating, that's a frightening prospect that bodes poorly for Australians' living standards and health.

As has been clear from the significant lifting of commitments this year by countries uncorrupted by fossil fuel corporations, what we do between now and 2030 is crucial to locking in the least worst scenario modelled by the IPCC -- in which the world briefly rises above 1.5 degrees but then slowly comes back down to just below it. The consequences of even that relatively limited rise in temperatures will play out for centuries and millennia.