The world needs to ratchet up its emissions reduction ambition at least five-fold for there to be any hope of limiting global warming to 1.5°C and avoiding dangerous climate change, an important new report has warned as global leaders meet to discuss the issue in New York.

The “United in Science” report, published ahead of this week’s 2019 Climate Action Summit sponsored by the United Nations, says that despite promising signs of ambition from many countries, the world is currently on track for a more than 10 per cent rise in emissions above 2016 levels by 2030.

This, according to data compiled by the World Meteorological Organisation, would lead to an increase in average global temperatures of between 2.9°C and 3.4°C by 2100, paving the way for catastrophic and irreversible climate change across the globe.

To get back on track – which the report stresses is still possible – will require an “urgent response,” including firm national commitments to cut emissions by 45 per cent by 2030, and achieve carbon neutrality by 2050. (This, of course, is the same target stipulated several years ago by Australia’s Climate Change Authority, which is now largely de-funded and ignored by the current Coalition government).

“There is simply no time to waste,” said UN Climate Change executive secretary Patricia Espinosa and UN Development Programme administrator Achim Steiner in the new report.

“Climate change is fast outpacing us and needs an urgent response by all segments of society.”

(Read also Richie Merzian’s on-the-spot account: Climate strikes have changed the rules of diplomacy at UN Climate Action Summit).

UN Secretary-General António Guterres said part of this urgent response means an immediate halt to subsidies for fossil fuels – which the IMF estimates at more than $5 trillion a year – an agreement to build no coal-fired power plants after 2020, and to put a price on carbon emissions.

So far, Guterres noted, 12 nations had shared their long-term strategies formally with the UNFCCC, while another 53 countries were currently working on LTS to submit by the end of 2020, mapping out the phasing out of GHGs from their economies by the second half of the century.

Australia, needless to say, is not one of those countries. Rather, it falls into the category of nations to have contributed to what the report describes as “a worrying growth in greenhouse gas emissions since the adoption of the Paris agreement in 2015.

In fact, Australia falls into the dismal category of nations that did not get to speak at this year’s global climate summit, because they have nothing to offer, and no one willing to offer it.

As Merzian points out here, Australia’s target of a 26-28 per cent emissions reduction by 2030 from 2005 levels is weak by any measure.

Australia is not on track to meet its target according to 2018 emissions projections, let alone to meet the Paris goals – even if you include the 367 Mt of controversial Kyoto Protocol carryover credits that would extinguish half the effort required to hit the 2030 target.

Prime Minister Scott Morrison, who is in the US but won’t be bothering himself with any climate talks, continually claims otherwise, however, and leads a government that is not at all convinced climate change is even something to worry about.

On the upside, Australian people – if not yet of the voting age – have shown themselves to be deeply worried, turning out in the hundreds of thousands on Friday to call for stronger action. And our leading scientists and academic researchers are also keeping up the fight.

“Australia’s political debate seems entirely disconnected from the scientific realities captured in …(the) report,” said Jon Symons is a Senior Lecturer in politics and international relations at Macquarie University.

“It is not only that the Morrison government lacks effective mitigation policies, it is failing to honour even some of its key promises. For example, it is not fulfilling its 2015 “Mission Innovation” pledge to double government spending on clean energy research and development by 2020.

“Meanwhile, the urgent need to develop negative emissions technologies has not yet entered mainstream debate. If current trends continue we may soon also be debating more drastic and risky interventions,” Symons said.

“This new assessment is another sobering reminder of the critical state of the climate crisis and a call on governments, businesses and civic society to act more determined and aggressively in reducing greenhouse gases emissions,” said Dr Pep Canadell, a contributing author to the report who is also executive director of the Global Carbon Project and chief research scientist at the CSIRO Climate Science Centre.

“Nothing in this report should come as a surprise but a confirmation of the trends well established by the scientific community, with a distinctive acceleration of climate changes in the past three decades, and particularly in the most recent one.

“How many climate records does it take to accept the unprecedented nature of what we are living and to act upon it?”

Elsewhere, Professor Dave Reay, the chair of carbon management at the University of Edinburgh compared the report to a credit card statement after a 5-year long spending binge.

“Arguably of most concern is the apparent acceleration in the rise of CO2 concentrations in our atmosphere,” he said.

“On top of still-growing emissions from human activities have come increased emissions from wildfires and weaker carbon uptake by the land and oceans.

“Time will tell if this weakening of global carbon sinks is a temporary blip or the beginning of a sustained reversal that rips control of future climate from our grasp. Either way, our global carbon credit is maxed out. If emissions don’t start falling there will be hell to pay.”