According to a major new report from the United Nations Environment Programme (UNEP) global warming will breach 1.5°C within a few years. Even its most optimistic pathway now peaks at 1.8°C.
We already know what these frightening numbers and dynamics mean. Europe has just endured its hottest summer on record, with an estimate of more than 36,000 additional deaths and losses estimated at €180 billion.
In August, a glacier collapse on the Nepal–China border killed more than 1,400 people. And here in Australia we are heading into summer after record-warm winters in Sydney and Melbourne, Adelaide’s second-hottest September day in a century, and a very strong El Niño forecast to peak within months.
The world has already experienced individual years above 1.5°C, but soon, we will cross that threshold on an average, not just an individual year basis.
It’s no longer a question of whether we cross it, but how far beyond the threshold we go, for how long, how we can return, and the damage done in the meantime.
As Australians we trust what we can experience and feel. And the measured data bear it out: while UNEP’s warning of 1.5°C overshoot is alarming, it is no surprise in a country whose land has already warmed by around 1.6°C above pre-industrial levels.
We can already see the harms: more intense heat, more severe disasters, growing pressures on ecosystems, agriculture and water systems that underpin our prosperity and wellbeing.
The growing threats to our low-lying Torres Strait Island communities, our Pacific neighbours and more broadly across our Indo-Pacific region are very real.
The report’s most confronting warning is that even a temporary overshoot of 1.5°C will have permanent consequences. Bringing temperatures down later will not undo all the damage. Communities, livelihoods and ecosystems will be lost, and the damages will be substantial.
As chairs of the Australian Climate Councils Network, we believe the implications of climate overshoot deserve focussed action, planned fairly.
Our network is the first of its kind globally, bringing together our country’s independent climate advisory bodies. Together, we help connect international climate goals with the practical decisions needed to reduce emissions, adapt to climate impacts, support communities and maintain economic prosperity through a transition that is already well underway.
Our members include a former state treasurer and energy minister, a capital city lord mayor and business leader, a federal judge who led the national workplace tribunal, a physician, and a climate adviser to a British prime minister.
We have helped guide climate policy at every level of government, with business and affected communities. With our collective expertise in climate science, economics, finance, health and public policy, our message is simple: exceeding 1.5°C is a call to urgent action.
Central to our advice is that every fraction of a degree matters and increases risks to people, communities and ecosystems. With more warming, adaptation becomes harder and more expensive, and the likelihood of irreversible losses grows. For example, scientists project that 99% of the world’s warm-water corals, like the Great Barrier Reef, could be lost at 2°C of warming.
The good news is that some of the actions we’re taking in Australia today are already bearing fruit.
Across Australia, governments, businesses and communities are building the foundations for a cleaner, lower-emissions economy. Our electricity system is halfway there, reaching more than 50 percent renewable energy in the last quarter of 2025. Australians are making the transition real at home: more than 4.3 million households have rooftop solar, nearly 300,000 home batteries were added in 2025, and battery-electric vehicle sales topped 104,000.
Cutting emissions and electrifying our economy can ease cost-of-living pressures and reduce exposure to global instability and fossil fuel price volatility at the same time. Rooftop solar, home batteries, efficient electric appliances and EVs reduce overall household, and business, energy costs.
The practical challenge is to help more Australians access those savings, particularly renters and households that cannot afford the upfront investment.
This highlights the importance of the need for a fair transition. Acting early is what allows changes to be planned, people to be supported into new jobs and for regional economies to diversify. Delay forces abrupt change that damages communities. It also creates uncertainty for investors, businesses and communities making decisions that will shape Australia’s economy for decades.
And the task is not just about carbon dioxide levels. It determines the long-term outcome; cutting methane is one of the fastest ways to curb near-term warming.
But even if temperatures eventually return to 1.5C after a peak, ecosystems, infrastructure and communities may not return to their previous state. Adaptation therefore needs to be a core pillar of climate policy, particularly for the communities most exposed to climate risks and economic disruption.
That is where independent climate advisory bodies can contribute. Our responsibility is to help governments act on this evidence to protect people and ease pressures on households today.
Crossing 1.5°C is not the end of climate action.
It’s the beginning of a harder chapter.
The Australian Climate Councils Network is a partnership of independent climate advisory bodies from across Australia. This article is authored by its Chairs: the Hon Matt Kean, Dr Arnagretta Hunter, Professor Nick Rowley, Dr Iain Ross AO, and Martin K Haese.
