Australian prime minister Tony Abbott has learned a few things over his first year and a bit in government. He can, for instance, make a carbon price disappear. He might even be able to make a renewable energy target disappear, along with billions of dollars in projects and thousands of jobs. But try as he might, he cannot make climate change disappear – either as a political or an economic issue, or as a fact of science.

For the past year, the Australian team managing the G20 process has been working with a grim determination to not mention climate change – either as a matter of substance in the talks or in the final communique. Abbott didn’t want simple messages about economic growth to be complicated by things as complex and confounding as climate change.

It didn’t work. Of course. In the end, the G20 became all about climate change. And even if the Abbott cheer squad in the Murdoch media sought to criticise and downplay the role of China and the US, some at least recognised the “headache” it posed, even if they were pitched as political, rather than economic terms.

We also learned something more about the Abbott government – that on the world stage it is incapable of grappling with sophisticated policy issues other than boiling them down to three word slogans or absurd schoolyard bravado – “stop the boats”, and his pledge to “shirt-front” Vladimir Putin.

At the G20, Abbott was more interested in complaining about the problems of implementing a $7 GP tax on medical visits. Fairfax described it as Australia’s “pimply youth” moment, the satirical website The Shovel said Abbott might just as well have been talking about parking meter problems in his home electorate of Warringah (and it’s true, there is a major issue).

World leaders couldn’t care less. But it speaks volumes of the inward nature of Abbott’s entourage that they could presume that the G20 would be interested in medical co-payments, and that they should be blindsided so easily by the climate commitments.

And don’t mistake the deliberate efforts of the G20 nations to embarrass Abbott on this issue, having grown exasperated by the Australian government’s actions over the past year.

A year ago, in Poland, Australian negotiators did a complete about-face on their negotiating strategy for a new climate deal. Where once the team had been co-operative and progressive, it became stubborn and intransigent. Even then, officials from the EU, the Americas and Asia were asking “what’s going on, Down Under.”

They were exasperated by Australia’s intent, at that stage behind the scenes, to exclude climate change from the G20 agenda. They were horrified when Abbott took domestic politics to the global stage at the CHOGM summit in Sri Lanka and labelled the Green Climate Fund, a critically important institution for the global climate talks, as a “Bob Brown bank”.

So the two most powerful leaders in the world, to declare their intent, chose a meeting just two days before the G20 to announce their landmark climate pact. Obama went further, using his opening speech on the sidelines of the G20 – to the youth of Australia in Abbott’s own back-yard – to underline the importance of climate change, to berate those countries who didn’t act, and to announce his country’s $3 billion commitment to the “Bob Brown” bank.

Japan chimed in with $1.5 billion. Even Canada said it would make a contribution. UK’s Prime Minister also chipped in with a back-slap against countries that didn’t take climate change seriously. German chancellor Angela Merkel followed suit on Monday, warning that the impact of climate change did not stop at Pacific Islands.

It seems clear that the biggest issue on the final communique were around Australia’s last ditch efforts to minimise the importance of climate change. “Trench warfare” is how the Guardian described it, quoting negotiators.

Treasurer Joe Hockey may be considered by some to be more moderate than Abbott, but he is no less ignorant. He said he was “too busy” to either listen to Obama’s speech, or to absorb its contents.

His dismissal of China’s share of the climate pact was to borrow the climate-denying Republican leaders who said that it was not incumbent on them to do anything until 2030. In fact, China will build 1,300MW of clean energy plants a week until 2030 to meet part of its undertaking. That’s nearly 200MW of wind, solar, hydro, biomass and nuclear a day – for the next 15 years.

That also means China will not need so much coal. And not so much Australian coal. It has halved imports, and may halt them altogether within years. It has slapped a tariff on Australian thermal coal imports that it will not lift for another two years, despite the much-heralded free trade agreement.

So when Hockey – looking decidedly uncomfortable – pretended that climate change was no impediment to economic growth, he was ignoring the fact that the two biggest customers for Australia’s biggest export may no longer have any demand at all for the Australian product.

But Abbott and Hockey’s ignorance knows no bounds. Abbott insists that China’s “20 per cent” non fossil fuel target means that 80 per cent of China’s electricity will come from coal in 2030. No, that 20 per cent target is for all energy, not just electricity, so the non fossil fuel component is more likely to be more than 30 per cent. And there will be plenty of gas in the final equation.

Abbott says he will “stand up” for coal. But he is about the only one. Because no banker now will take the risk on the long term infrastructure to bank-roll the possible short term gains of the Galilee Basin coal provinces, the Queensland government will throw in taxpayers money.

These are exactly the sort of fossil fuel subsidies and investments that the International Energy Agency, and the United Nations is arguing against, and goes against the undertaking of the G20 – repeated in the latest communique – that all the developed nations will seek to phase out those subsidies.

Abbott insisted that coal was critical to lifting 1.3 billion people out of poverty, but even the International Energy Agency has dismissed this as nonsense, on several occasions. Others have too. India says it will solve its immediate energy poverty problems with solar and storage, and may even drop imports of thermal coal in coming years. (Update: India PM Narenda Modsi says he doesn’t want energy sources that will “melt glaciers”.

Despite all this, nothing appears to have registered with Abbott. He emerged from a meeting with Merkel, who is leading the most radical decarbonisation of any major economy, and was the first big funder of the Green Climate Fund, to announce that Australia will not contribute anything.

He insisted that Australia was doing “quite enough” with its $2.5 billion Direct Action program, and the $10 billion Clean Energy Finance Corporation that he is also trying to close. Australia, therefore, will continue to be a pariah on the world stage, digging its economy into an every deeper black hole.

We are, quite possibly, witnessing the most incompetent and ideologically blind government ever to hold power in Canberra. It’s effectively the Tea Party of Australia, pretending to be something else.