The maps that could 'revolutionise' how Australia handles bushfire risk

Dozens of firefighters are gathered outside a rural brigade in Sydney's northern outskirts, listening intently to a briefing about a hazard reduction burn.

"It's a fairly small burn, but it's fairly complex," Captain Scott Jones tells the yellow-clad volunteers.

"It's perfect weather conditions for it."

That has been a rare statement in the lead-up to this year's bushfire season.

The New South Wales Rural Fire Service (RFS) has only been able to complete about 40 per cent of its prescribed burns, largely because of increased rainfall.

The RFS says climate change is not only interrupting preparations, but is creating longer and more intense fire seasons, pointing to the summer of 2019-20 as an example.

A royal commission was held after that horror season, which saw 3,000 buildings destroyed and about 24 million hectares of land burned across multiple states.

As a result of that inquiry, a special team at the CSIRO has been tasked with building maps to investigate Australia's bushfire hazards and how the risk will shift with climate change.

Its latest data has been provided exclusively to the ABC — a careful calculation of fuel type, terrain and weather, combined with one possible future climate scenario.

The CSIRO has analysed seven different climate models, but selected this one to share as it's a "reasonable representation" of those examined, where global emissions decrease, but not enough to reach net-zero.

So, what will climate change potentially mean for the risk of you losing your house in an extreme bushfire?

For each area across Australia, the darker the red, the bigger the increase in the potential risk, compared to current conditions. This is associated with warmer, drier and windier weather.

The darker the blue, the more the risk could possibly reduce. This means there's likely to be more moisture in the environment, through weather patterns like rainfall or cyclones.

No data means that scientifically there's not enough vegetation for a fire to reach its full potential within the area.

Some of the areas where the risk could possibly fall include Far North Queensland, and the area surrounding and including Canberra.

Areas which may experience a higher fire risk include national parkland in the west of Tasmania, near Lorne along Victoria's Great Ocean Road, and in the Northern Tablelands on the NSW north coast.

While this modelling is not a prediction of the future, its aim is to allow authorities to better plan for a potential catastrophic fire situation.

It assumes a worst-case scenario where hazard reduction burning doesn't happen, and climate change doesn't affect vegetation.

While there are a few patches of Australia that could raise concerns, population data indicates most Australians currently live in areas where there could be no change or only a slight increase in bushfire risk.

But it doesn't mean more population-dense areas are completely protected from fire risk in the decades ahead, says Justin Leonard, the lead researcher of the National Bushfire Intelligence Cabability (NBIC) team.

"We're not expecting to see a dramatic escalation in how our built-up urban centres are exposed," he says.

But Mr Leonard says recent events in the United States — where fires reach built-up urban areas and houses burn neighbouring houses down — should be considered.

"Australia hasn't had those types of events occur … [but] we have to be very careful that we don't transition into setting our urban environments up to be vulnerable in that way."

While individual states and territories all have their own hazard maps, Mr Leonard says there is benefit in having an overarching "unified" view.

He says it will assist states that are "either poorer in time or funding to uplift them at a greater rate".

"It's just human nature that if you ask seven different states or territories to implement [risk mitigation strategies], they're all going to take their own unique approaches," he says.

"What we can do as a national science agency is … to build a unified system that simply builds on the best of what states are being able to do, and put our perspective on top of that as well."

The NBIC has also been working on other detailed maps exploring how intensely fires could burn in different areas of the country.

The map below shows the current risk of a one-in-50-year bushfire and its potential severity.

The more yellow an area appears, the more intensely a fire could burn, taking into account fuel, terrain and weather.

But a fully-developed fire that's considered dangerous to buildings could develop in areas coloured light purple.

A detailed version of this map is not ready to be published — and is unlikely to be available to the public this fire season.

The NBIC's early work has already been used by the Department of Health to provide evacuation advice for aged care facilities and assess the risk to hospitals and health services.

Mr Leonard says he also wants to make as much information available to the public as possible.

"The more accessible that data is for everybody — right down to the owner of the property that's been considered to be at risk — is the key outcome for having impact and relevance."

Preparing a home for future risk

Localised data could prove to be relevant for Australians like Julian de Blonk, who moved to the Tasmanian town of Kettering earlier this year to retire.

Early NBIC data suggests his bushfire risk is currently lower than other parts of the country.

But based on the above climate change scenario, the bushfire risk could significantly increase in the decades ahead.

He has taken several precautions while building his house, including using cladding and double-glazed windows.

In addition to protecting his house, the work could also save him money when it comes to his insurance, under a new scheme.

Mr de Blonk has registered all the work undertaken with the Resilient Building Council and received a five-star rating.

Two insurers have so far come on board to offer premium discounts for those recognised for resilience work, and Mr de Blonk is hoping to benefit when his renewal comes up.

"At the end of the day if you're an insurer, surely you're going to be wanting to insure properties that are resilient against fire, or against flood, or whatever the risk that is being taken on," he says.

"I do think it's important, and if the climate is becoming more extreme, well even more so."

The Insurance Council of Australia has said increasing risks, due to climate change, are responsible for recent record high costs.

The bushfire royal commission recommended the council give people guidance on mitigation actions that insurers would recognise when setting premiums.

The NBIC hopes that providing more detailed data could help bring down costs in some areas, by allowing more individualised assessments.

But the chief operating officer of the Insurance Council of Australia, Kylie Macfarlane, says it could "go both ways" — if it exposed a higher risk, someone's premium could go up.

But she says the main factor driving up disaster losses is expanding development and urbanisation, saying it was "fundamentally important" that houses are being "built in the right places".

"While household mitigation and resilience is important, we also do call on government to ensure that that national hazard database is built and completed, the building codes are appropriate for the areas that are being built in."

Telco looks to bolster networks

In the wake of Black Summer, telecommunications provider Optus set out to find ways to better protect its infrastructure from extreme fires.

It connected with the NBIC, which used its datasets to analyse the risk at over 7,000 towers across the country.

Work has since been undertaken at 40 prioritised sites to reduce the chance of them being destroyed in a bushfire, including one at Dixons Creek, in Victoria's fire-prone Yarra Ranges.

Mr Leonard recently returned to the site with the Optus crew to assess how the prevention measures are holding up.

His team created maps like the one below, which demonstrates how a potential fire would impact a tower.

The red dots, which surround the current mobile tower at Dixons Creek, indicate a bigger potential for structure damage.

Such towers are vulnerable to ember attack, particularly from underneath the footing, so metal shields have now been installed to prevent debris collecting there.

Optus says the chance of the 40 towers being lost across the country during a catastrophic fire has been reduced by six times because of the work.

"It's an absolutely massive number, and what it means for the community is an absolute game changer," Jayson Grool, Optus's general manager of Victoria said.

"Previous (to the NBIC) it was a state-by-state piece of work, and the CSIRO has pulled it together nationally, which is absolutely brilliant."

Hazard reduction burns in the face of climate change

Back on the northern outskirts of Sydney, the RFS firefighters are happy with how their prescribed burn is going.

It's been two decades since this area in Mount Colah has burned and the fuel load is high.

"This is what we call a low-intensity burn — we have flame height of less than 1 metre, with a really slow spread, it's exactly what we're looking for at the moment," operational officer Damien Fear explains, pointing to the flames.

"It's a three-and-a-half hectare burn, which will offer protection to about 100 homes."

According to the NBIC's modelling, this area could see an increase in bushfire risk of up to 20 per cent.

The use of hazard reduction burns was debated in the aftermath of Black Summer, and the royal commission called for better communication with the public about how fuel loads were managed and the increased use of Indigenous fire management.

It also tasked the NBIC with developing nationally consistent classifications and data on fuel loads, which it is currently undertaking.

But the path from here is unclear.

Mr Leonard says the work of the NBIC could take many different turns, either focusing on short-term projections, or longer-term ones — dependent on it securing future funding, to build on the work of the states.

"I'm actually hopeful of finding examples of where there might be upcoming duplication, because that's like finding a research partner or a collaborator to do work with," Mr Leonard says.

With the arrival of summer, fire services across the country are preparing for the season ahead.

At the same time, the royal commission is preparing to hand down its final report.

Due to be released early next year, it is expected to show that 33 recommendations have been addressed and 20 are underway.

While the progression of climate change is yet to be seen, Mr Leonard is confident the commission's recommendations are moving things in the right direction.

"Oh, most definitely," he says.

Credits:

Reporting: Natalie Whiting and Madi Chwasta

Development: Katia Shatoba

Design: Brody Smith

Digital production: Madi Chwasta, Brody Smith and Mark Doman

Data notes

• The map showing the potential increase and decrease of hazard is the average percentage change across an SA1 boundary of a measure called "expected fireline intensity". This is a measure of the energy released per linear meter by the head fire front for an extreme event, defined as an event which has a 2 per cent probability of occurring on any given year.
• Fireline intensity calculations are based on the same fire behaviour models that underpin the new Australian Fire Danger Rating System, and incorporate 43 years of hourly weather time-series data, and eight types of vegetation that are mapped across the country.
• These models are then combined with a climate model. In this case, the CSIRO has chosen the model CNRM-ESM2-1, and more information can be found here. This model is part of the CMIP6 model suite, which reflects the latest climate change science.
• This model is applicable to a 2090 projection horizon, following a SSP370 emission scenario, which the international community considers the most likely worst-case scenario. SSP370 considers some positive change towards global emission goals but not enough to reach net-zero or reverse the current climate trajectory.
• The CSIRO is analysing seven different models and two emission scenarios, so this data is only partially representative of the agency's work.