Ardern's hypocrisy is not absolved by this almost certainly being a short-term poll-driven gimmick, with any Commerce Commission inquiry into fuel prices likely to take years once participants litigate both the process and any draft findings.
Her rhetorical push for lower petrol prices underlines that when the polls demand it, Ardern puts voters' short-term economic interests ahead of the planet.
While deeply cynical, that is in fact the right stance.
The IPCC report and the global political response shows there is no value in New Zealand doing anything to achieve zero net emissions if such moves come with any cost at all.
IPCC co-chair Jim Skea suggests it remains possible "within the laws of physics and chemistry" for the world to avoid catastrophic global warming.
But his sub-text is that the laws of politics mean it is not.
Ardern is not the only world leader to ignore the report's release on Monday. China, the US, India and Russia are responsible for more than 50 per cent of global emissions, with the first two responsible for 40 per cent alone.
It is another annoying law of physics and chemistry that these four countries will determine whether global warming passes the catastrophic 2C or stays within 1.5C.
Steps by the likes of Japan, Brazil, Germany, Indonesia, Canada, Mexico and Iran may have a tiny effect at the margins. Everyone else is irrelevant.
Another way of putting it is that 100 companies are responsible for 71 per cent of global emissions. Your SME buying electric vehicles or printing on both sides of the paper makes no difference at all.
A counter view is that what New Zealanders do is as relevant as what any other collection of five million people do, but that avoids the point.
Ardern, and even leaders of mid-size powers like Australian Prime Minister Scott Morrison, do not have the regulatory power to affect the emissions behaviour of a sufficiently large number of people or businesses.
Only Xi Jinping, Donald Trump, Narendra Modi and Vladimir Putin do, and only if they act in concert.
This is why Barack Obama dealt directly with then Chinese premier Wen Jiabao and then Indian Prime Minister Manmohan Singh when salvaging something from the UN's 2009 Copenhagen fiasco.
Nine years later, Trump has withdrawn the US from the IPCC and the White House says it is already doing everything it plans to do.
Putin denies human-caused climate change and the Kremlin points to Russia's GHG emissions having already fallen significantly since 1990 following the collapse of the polluting communist system. Neither he nor Xi or Modi have had anything to say about this week's IPCC report.
There will be no agreement between these four when tens of thousands of delegates jet into Katowice for the IPCC's next climate jamboree this December.
If the IPCC report is accurate, this means all is lost. Catastrophic global warming cannot be avoided.
It therefore makes no sense for Ardern to worry about New Zealand's emissions, which account for just 0.2 per cent of the global total. No domestic mitigation measure New Zealand takes will make the slightest difference to the extent of climate change we face.
The only meaningful climate-change initiative New Zealand has ever taken was Tim Groser's Global Research Alliance on agricultural emissions which now has 51 countries working together to reduce the 22 per cent of global GHG emissions that come from methane and nitrous oxide.
All else over the past 30 years has been mindless virtue signalling for the domestic audience.
Given the attitude of Xi, Trump, Modi and Putin, Ardern's focus, and that of her successors, should now be on adaptation.
It is her job to plan for how New Zealand will survive with higher temperatures and protect itself from the hundreds of millions of climate refugees the IPCC report suggests will be heading our way.
- Matthew Hooton is managing director of PR and corporate affairs firm Exceltium.