This is the issue that should decide our vote, yet both major parties persist with assertions that they 'have a plan' to take the country into the future. It's nonsense. They plainly don't. Instead our politicians depend on us passively accepting ridiculously glossy economic projections. These fall apart the minute they're juxtaposed next to the massive cost of future climate disasters, let alone those that are already wreaking havoc to our agriculture, our livelihoods, and our homes.

Treasury prides itself on projections, however the recent Budget effectively waved a wand and dismissed the real effect of climate change on the economy. Any examination of Treasury's prediction hit-rate placed side by side with those of an astrologer would undoubtedly award the soothsayer the crown for accurate forecasting. The department's lacunae today is its continuing (and genuinely amazing) refusal to incorporate appropriate climate change assumptions into future modelling in a meaningful way.

The world's environment is facing massive transformations. Geographers are struggling to explain what's happening and yet, our economic bureaucrats continue plugging away oblivious, inserting increasingly ridiculous numbers in spreadsheets before gasping in amazement as "unforeseen events" render their forecasts nothing but garbage.

But if the federal prognostications have been reduced to little more than the guesses of groups of druids circling around bonfires, there is political method to this. The current government either doesn't believe climate change is an issue, doesn't believe anything can be done to affect it or can't cope, intellectually, with anything more ephemeral than a lump of coal or a fighter plane - or, quite possibly, all three at once.

One still suspects, as far as Scott Morrison's concerned, the South Coast bushfires were just a disastrous end to his Hawaii holiday and the Lismore/Brisbane/(insert the region of your choice) floods simply proved how stupid people who don't live in the Shire really are. So how is it that Labor hasn't been able to press home their advantage on these issues and why isn't Anthony Albanese spruiking the reality of climate change every day?

You can almost imagine the scene three years ago - ALP strategists meeting while still shell-shocked after losing the unlosable election. Easier to simply blame a 'big target' strategy than accept that other failings (abolishing franking credits and slack campaigning) might have been more responsible for the disaster on election night. The result was a party afraid of putting up policy.

Labor assumes anybody who believes in climate change will plump for Labor (their votes returning via Green preferences). So the party's assumed it doesn't need to occupy this terrain and is going after swinging voters making their decision on other matters.

Perhaps back then that made sense. The difference now is we've just lived through three years of exactly what was predicted to occur as a result of climate change occurring. Fires and floods can no longer be dismissed as 'once in century' events. Instead they're going to recur and intensify as our environment degrades further and gets caught up in a feedback loop where disaster builds upon disaster and the entire world loses the resilience it requires to escape the next catastrophe. Yet Labor is pretending it can ignore the urgent need for holistic policies on this vital matter as it attempts, instead, to bribe potential swingers. In doing so, Albanese has passed by a huge opportunity to exploit this as major issue in the way Kevin Rudd did 15 years ago.

The problem with this is that today climate change bleeds into every other issue - from Treasury's guesswork to international relations. It's not an issue that ends at our borders.

MORE NICHOLAS STUART:

Our neighbours, like the Solomon Islands, are well aware of Peter Dutton's cheap joke in Port Moresby back in 2015. While he, Tony Abbott and Scott Morrison were caught standing, waiting for a Pacific Islands Forum meeting to begin, when he didn't see the camera microphone overhead, Dutton sneered, "Time doesn't mean anything... when you're about to ... you know, have water lapping on your door".

The trouble is, seven years have passed since that comment and, throughout the intervening period, Canberra has continued to make it clear this country doesn't give a damn about the islanders' concerns. They aren't dumb. They know that all our talk about a happy and thriving Pacific family is just so much noise, motivated simply by a desire to keep China out - it doesn't mean Australia is either prepared to reduce greenhouse emissions or join in international action that might make a difference.

The result was predictable. We pressed full throttle on our emissions and abandoned the canoes in our wake, paddling desperately to catch up. Australia powered away, leaving the neighbours floundering in our wash and that's why today the islands have realised that Beijing will offer just as much money as Canberra will, but without strings.

Australia's failure to act on climate is feeding in to these decisions; derisory laughter at 'Pacific time' while ignoring genuine environmental concerns has now come back to haunt this government during this election campaign. Nobody can draw a straight line between Morrison (and Dutton's) failure to accept the reality of climate change and China establishing a base in the Solomon's, but everything is always connected to everything else and the linkage is implicit. Australia demonstrated conclusively it didn't care about a matter that's existential to the islanders and so they are no longer worried about doing what this government says.

This is our last chance to do something about the environment: its importance overwhelms every other issue combined.