The Prime Minister, Scott Morrison, shackled by what appears to be his own lack of sincerity and belief, and an inability to drag the climate recalcitrants in his government's ranks into the 21^st century, missed the perfect opportunity to reset Australia's ailing climate change policy for the better.

What must the delegates from many of the world's leading industrialised nations have been thinking when, after listening as country after country announced its intention to ambitiously upgrade their 2016 Paris agreement targets, Mr Morrison - the 21^st of the 27 speakers - essentially said his government was betting on technological innovation and market forces to do the job for it.

And, if that wasn't enough, then came the realisation that after all that had been said and done Australia was still not committing to zero net carbon dioxide by 2050.

The wonder is that the PM could deliver his lines with a straight face in view of just how little he, and we, brought to the table compared to almost every country taking part.

Was he one of the people Greta Thunberg had in mind when she told a US congressional hearing taking place at about the same time: "How long do you honestly believe that people in power, like you, will continue to get away with it?" Probably.

The 18-year-old from Sweden told the lawmakers her generation would write the history books covering this period and determine how the current crop of world leaders are remembered.

"So my advice for you," she said, "is to choose wisely."

The UN Secretary-General, Antonio Guterres, could have almost been addressing Australia by name when he said: "We must put a price on carbon, shifting taxation from income to carbon, end subsidies for fossil fuels and accelerate investment in renewable energy and green infrastructure".

An immediate effect of the Biden climate summit has been to marginalise Australia's overtly minimalist approach to what is an existential planetary crisis to the point where it is now little short of ridiculous.

Consider this fact; even Brazil's president, Jair Bolsonaro, whose record to date on climate change and the environment would qualify him for a spot on the Coalition frontbench, has undergone a change of heart.

He has pledged to make Brazil carbon neutral by 2050, 10 years ahead of the current schedule, and to eliminate illegal deforestation by 2030: "I cannot agree more that we must be more ambitious on the climate agenda," he said.

President Biden pledged to cut America's greenhouse gas emissions in half by 2030, Japan's new 2030 target is 46 per cent, Canada's is 40 to 45 per cent - up from 30 per cent, and China has agreed to "phase down" coal consumption from 2025 in order to begin reducing emissions from 2030 onwards.

"China has committed to move from carbon peak to carbon neutrality in a much shorter time span than what might take many developed countries, and that requires extraordinarily hard efforts from China," President Xi Jinping said.

The one positive outcome for Australia from the summit is that not even the most adamant climate change denier can now fail to be aware of how far out of step we are with the rest of the planet.

While the PM's homely rhetoric and use of the wedge may serve him well on the hustings it doesn't cut it at this level. At the summit actions were always going to speak louder than words.

On Thursday night the whole world saw that our emperor has no clothes.

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