Colonisation, not climate change, first primed these forests to burn

by bpckle | Oct 8, 2026 | In the Media

Bushfire season is here. The Bureau of Meteorology expects the declared El Niño to be strong to very strong. Southeastern Australia is bracing for a long run of dangerous fire weather.

Weather is only part of a catastrophic fire. Another factor is fuel – combustible vegetation. Our new research, published today, shows the current fuel load in some Australian forests is not “natural”. It is a product of colonisation, which loaded Australian landscapes with fuel a century before human-made climate change began.

Consider Croajingolong National Park, in Victoria’s far east. It has every level of protection possible: national park, designated wilderness area and UNESCO Biosphere Reserve. It’s also one of the most repeatedly incinerated forests in Australia: the 2019–20 Black Summer fires alone burned through 90% of the park.

The reprieves between bushfire have collapsed, from roughly 40 years in the late 1800s to about five years in the most recent decade.

Reading a natural archive

We conducted this research in partnership with the Gunaikurnai Land and Waters Aboriginal Corporation, coauthors of the study, on GunaiKurnai Country in the Croajingolong National Park, which takes its name from the Krauatungalung people of the GunaiKurnai.

Our archive is Purghagoolah, called Lake Elusive by colonial mapmakers, a deep lake inside the park. Our data were pollen, charcoal and sediment.

In February 2021 we took a core sample – a cylindrical piece of layered sediment – from its depths to retrieve evidence of a 1,000-year history. The pollen and charcoal within the sediment, blown in from the surrounding 10,000 square kilometres, offer records of a vast slice of Australia’s most frequently burnt forests.

Pollen reveals what grew, charcoal tells us about fire, and the infrared spectra of this charcoal reveals how hot these fires were. This allows us to separate cooler cultural fire – where low-intensity fires were strategically applied to the landscape – from hot wildfire. In addition, magnetic minerals track erosion of soil into the lake, and radiocarbon and lead dating anchor this history in time.

Before and after

We found that for more than 800 years, frequent, low-temperature cultural burning under GunaiKurnai care held this land as stable, open woodland. In this period, the landscape was low in charcoal, rarely scorched by hot fires, and without the erosion that follows.

There was no lack of dangerous fire weather in the past. Fire seasons as severe as Ash Wednesday, Black Saturday and Black Summer occurred over these centuries, yet cared-for Country did not experience catastrophic fire.

However, during the colonisation of Gippsland, frontier violence and massacres between the 1830s and 1860s removed GunaiKurnai people from Country and disrupted a millennia-long relationship of care.

After colonisation, everything in the sediment core changes. Hot fire becomes dominant, shrubs thicken, eucalypt cover surges to nearly four times pre-colonial levels, and open woodland becomes today’s flammable forest. Charcoal rises sharply, alongside an increase in hot fires. Soil washes into the lake, no longer bound by living plants.

All this took place before human-driven climate change properly began, echoing what we found across southeast Australia in a 2022 study: a region-wide increase of shrubs following the British invasion.

The outcome is a catastrophic wildfire loop: each hot fire drives thick, flammable regrowth that primes the next climate-driven fire. Climate change did not start this vulnerability – it amplifies one that colonisation began.

A wilderness that colonisation built

All this, in a place we protect as pristine wilderness. Official vegetation maps treat Croajingolong’s forests as the natural, pre-colonial baseline state. But our data demonstrates otherwise – the wilderness we protect is one colonisation made. Management relying on that false baseline entrenches fire danger, and ignores the ecological and cultural relationships held within the now-lost woodlands.

Aboriginal people have long said it plainly: wild Country is sick Country, Country that has lost its people and their care.

GunaiKurnai ancestors were born with towera (fire), an essential part of the old peoples’ practical daily life on Country, as GunaiKurnai Elder and study coauthor Uncle Russell Mullett says:

Not treating country with towera, Country becomes extremely dangerous for GunaiKurnai, animals, and plants. Studies such as this provide firm scientific evidence to support towera land management initiatives for Country.

A region-wide transformation

The waters of Purghagoolah sit within roughly 3 million to 4 million hectares of forest that runs unbroken from the Victorian Central Highlands to the New South Wales south coast. Around 80% of it is resprouting eucalypt forest, that could benefit from regular cooler cultural burns.

The rest of these forests, around 20%, is the fire-sensitive mountain and alpine ash forest of the valleys and high country. They have a fundamentally different fire ecology that requires hot fire to release and germinate seeds separated by long fire-free intervals. Yet these atypical, less extensive forests dominate public discourse and fire policy. This fosters an ethos of fire suppression that increases risk across vast forest areas.

Bring back the carers

None of this diminishes the threat of climate change. Rather, our research emphasises the parts of the story that have been historically overlooked: the fuel, and the care by people who once kept it in check.

Fire management must grow beyond hazard-reduction burning and climate adaptation into restoring healthy Country and cultural burning, with Traditional Owners resourced to lead the way. Cultural burning reduces catastrophic fires, is better for the soil, and protects our plants and animals.

Purghagoolah leaves us with hope. Through at least eight centuries of severe fire weather, fire stayed in human hands and catastrophic fire was contained. Country needs people. When Country is cared for, climate is not the only factor that dictates how it burns.

Michael-Shawn Fletcher receives funding from the Australian Research Council.

Anthony John Romano and Russell Mullett do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

Electric long-haul trucks could become a reality sooner – if there’s no driver

by bpckle | Oct 7, 2026 | In the Media

It’s hard to run heavy trucks without fossil fuels – especially in Australia. They’re big, heavy and cover long distances. Powering big rigs with today’s batteries suffers from added weight and cost. Then there’s recharging time.

For smaller trucks covering shorter distances, the task is much easier. The shift is already on in nations such as China. But many experts predict long-haul battery-electric trucks won’t beat diesel on total running costs until the 2030s, when battery prices have fallen far enough.

My recent study suggests that timeline could be too pessimistic for one reason – the emergence of driverless trucks, which are being tested on public roads in the United States.

Australia already has a large fleet of driverless trucks carrying ore in the Pilbara. None are currently on public highways – but that could change. Late last year, transport ministers agreed to allow conditional deployment on selected public roads beginning in 2027.

So far, public debate has focused on driver jobs and safety. But there’s a key factor which we’re not talking about – money. Autonomous trucks change the economics of freight so much they tip the balance in favour of electric.

Drivers make trucks go faster – but at a cost

Today’s heavy trucks have drivers, which means every hour on the road is an hour of wages. To keep wage costs low, freight companies encourage drivers to drive at the speed limit (100kmh for heavy freight) and get the trip done.

Speed has a large hidden cost – especially for heavy freight. Air resistance rises sharply as a truck goes faster, meaning a fast truck uses more fuel per kilometre than a slow one. But for a driven truck, arriving sooner avoids enough expense in the form of wages that it usually outweigh extra fuel costs.

If there’s no driver, the balance flips.

For an autonomous diesel truck, it doesn’t matter as much if the trip takes a bit longer. Using less energy per kilometre means burning a little less fuel.

The difference is more pronounced for autonomous electric trucks, where slower, more energy efficient trips could make it possible to use trucks with smaller, cheaper battery packs. Smaller battery packs also means a truck can carry more freight.

Our modelling shows the optimal speed for an autonomous electric truck is around 80km/h. Because there’s no driver who needs to rest, the trip can potentially be made without stopping.

Sydney to Melbourne, slow and steady

To test whether autonomous electric trucks change the financial equation, I modelled Australia’s busiest freight corridor, Sydney to Melbourne.

The result: autonomy made electric trucks much more competitive with diesel. The effect was the equivalent of a sharp fall in battery prices of A$34 a kilowatt hour. (As of 2025, battery prices were about A$162/kWh.)

In effect, autonomy would make electric trucks significantly more financially appealing and could accelerate adoption by several years.

Freight companies would gain more if they used driverless trucks more hours of the day. At present, a typical long-distance diesel truck is driven 25% of the time.

If autonomous trucks could run 50% of the time, that would boost the financial appeal again. The effect would be the equivalent of cutting battery prices by A$75/kWh.

There’s a crucial caveat: autonomous electric trucks gain this advantage as long as they do most of their charging cheaply at the depot to avoid paying fast charger rates on the Hume Freeway.

Autonomous electric trucks are best suited to medium routes

Most driven electric trucks currently available work best on shorter routes (under 600km). That’s good news, because complex urban environments are likely to be reserved for driven trucks, for safety and regulatory reasons.

Autonomous electric trucks will likely be restricted to specific corridors outside urbanised areas for safety, regulatory and technical reasons.

Three medium-length interstate corridors are well suited for trucks combining autonomy and electrification – Sydney to Melbourne (877km), Brisbane-Sydney (915km) and Adelaide-Melbourne (~726km). These are the busiest in the country.

From impossible to possible

Heavy trucks were long thought to be too hard to electrify. But plunging battery prices have made urban delivery trucks viable, while larger electric trucks are now being released.

My research suggests it’s now possible to electrify much of our heavy freight – and that going autonomous would accelerate financial viability over busy medium-length routes.

Authorities will have to be satisfied that these trucks are safe and resolve questions over potential job losses. But over time, the favourable economics of self-driving electric trucks may well be enough to make them a reality.

Anthony Wiskich does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.