Six years ago, I was one of hundreds of official delegates that stood in a makeshift UN plenary hall at Le Bourget when the Paris agreement was adopted after years of negotiations.

It was then, and may well remain, the most significant thing I have ever been part of in my life.

Unfortunately, my own country has now shown it is prepared to break both the letter and spirit of the very agreement it signed up to. This is especially galling given the extent Australia went to in Paris to align itself with those fighting for the strongest possible agreement.

With the events of last week, the Morrison government has shown that it quite simply does not do what it says on the world stage. Our climate indifference isn’t just reckless for our economy, our environment and our people. It is also reckless for our diplomacy as Morrison’s visit to Glasgow will surely now demonstrate.

There are four critical promises Australia made in Paris which it has now broken. These weren’t just handshake agreements, they are international law.

First and foremost, Australia agreed that every country should come back to the table at COP26 to ensure the short-term targets set for this decade represented the “highest possible ambition”. That is what Glasgow is all about and more than 100 countries have now made new commitments for 2030 in the lead-up, including the United States which we originally established as a benchmark for our own ambition.

Instead, the Morrison government quietly informed the UN on New Year’s Eve last year (when most public servants weren’t even working and most Australians were too busy firing up their barbecues to pay attention) that they didn’t intend to honour that promise. The government’s latest decision to not even align our existing target with our new projections is a completely gutless decision. It wouldn’t have even required them to do an ounce more, but would have at least demonstrated they understood their international obligations.

Australia has also callously ignored its promise to deliver on the Paris agreement’s long-term goal to reach net zero emissions globally by 2050.

Even by Yes Minister standards, calling the government’s net zero pamphlet a “plan” is courageous.

There are no new policies, no concrete pathway to get there, no cap on fossil fuels and no specifics. All the heavy lifting is either pinned on the hope of future technologies, or reliant on using carbon credits (effectively accounting tricks which do nothing for the planet).

A genuine net zero plan would involve detailed and transparent modelling, be enshrined in legislation, and be coupled with an independent statutory process to establish our short-term targets along the way. That is what the conservative government in the UK has done, as well as our friends across the Tasman and increasingly many in the Pacific.

Here in the Pacific is where Australia has most sensationally broken a third promise under the Paris agreement: to channel our climate finance through a single global mechanism in the Green Climate Fund (GCF) to make it easiest for those on the frontline of this climate crisis. Having followed the Trump administration out the door of the GCF, we are yet to return with our tail between our legs meaning we are effectively isolated amongst the major donor nations.

Those that point to the need for additional short-term action from the likes of China are right to do so. But those who ignore Xi Jinping’s long term pledge to decarbonise the soon to be world’s largest economy do so at our peril and also forget a fourth major promise Australia made in Paris which is that developed countries should take the lead.

The greatest tragedy is that it need not be this way.

Australia not only has the potential to be a clean energy superpower and global climate leader, it has an imperative to do so. As the government has now at least admitted, coal can’t be our second largest export forever, and we urgently need to find a way to replace this on our trade balance sheet.

In Paris, I might not have been part of the Australian delegation, but I was proud to be an Australian advising our regional neighbours in the Marshall Islands – some of the most ambitious in the world. It was the Marshall Islands that first inserted into the negotiating text the idea of the IPCC’s Special Report on 1.5C which later proved pivotal for demonstrating this was just as important for the global community as it was for those on the frontline. It was the Marshall Islands that first proposed the idea of a five-year process to ratchet up ambition which is the whole reason we are focused on 2030 at this moment. And it was the Marshall Islands that first proposed the idea of a long-term goal of net zero emissions.

It was also the Marshall Islands that formed the High Ambition Coalition that brought together more than 100 progressive countries and which Australia was hell bent on being part of. But after three years of a government that has repeatedly trashed the science, bemoaned helping finance the world’s adaptation to climate change, physically brought lumps of coal into parliament, put fossil fuels at the heart of our economic recovery from the pandemic, and been absent at the wheel when the catastrophic climate events we are all trying to avoid come barrelling home, it is difficult to argue that the EU and others were not rightly sceptical as to Australia’s bona fides then. Just as they will now as the prime minister arrives in Glasgow and as they construct a new regime of carbon tariffs designed to punish precisely those that haven’t lived up to the promises they made in Paris.

• Thom Woodroofe worked as a diplomatic adviser in the negotiations of the Paris agreement