But investments in early fire-detection technology, resilient housing, firefighting aircraft and critical infrastructure could significantly reduce losses.
Emergency Leaders for Climate Action released the findings on Thursday in a report that found cutting bushfire damage by 20 per cent could prevent more than $39 billion in economic harm and protect more than 5600 jobs each year.
The research comes after the Bureau of Meteorology warned of unusually warm conditions over summer as the El Nino weather pattern strengthens, and after the Australia and New Zealand Council for Fire and Emergency Services warned bushfire season could begin early.
The report, Prepare or Pay: Counting the Cost of Climate-fuelled Bushfires, used economic modelling from ConnellGriffin to estimate losses caused by bushfires over the next 30 years.
It found the growing number of fires could cost the Australian economy $181.7 billion over three decades, or an average of $6 billion a year.
A disaster on the scale of the Black Summer bushfires would cost $27.7 billion, while major fires could cost $16.1 billion every three to four years.
Harm to human health accounted for the biggest share of economic loss, it said, followed by lost business output, damage to buildings and infrastructure, and destroyed homes.
The economic estimates were conservative, report co-author Janice Lee said, and did not quantify losses to wildlife, ecosystems or cultural heritage.
"What used to be a once-in-a-generation bushfire is actually occurring more frequently," she told AAP.
"Australia is in a new era of bushfires and what we're seeing and will be seeing over decades is more frequent, more intense, longer bushfire seasons, and that will have escalating economic costs nationally."
Investments in bushfire prevention and preparation by federal, state and territory governments could reduce their economic impact, the study found.
Changes could include upgrading homes to meet the national bushfire standard, investing in early-detection measures such as infrared and aerial technology, and ensuring mobile phone towers had 48 hours of back-up power in high-risk areas.
Reducing bushfire damage by just one fifth could prevent $39.4 billion in losses, Ms Lee said, and protect $17 billion in tax revenue.
The report also recommended efforts to strengthen industrial pollution restrictions in the Safeguard Mechanism, cap the diesel fuel tax, and stop approving new and expanded coal and gas projects to address the causes of global warming.
The toll of bushfires extended beyond money, former ACT Emergency Services Authority commissioner Peter Dunn said, with towns such as Cobargo, on the NSW south coast, still rebuilding after the Black Summer fires.
"We're saying start preparing now," he said.
"We have the data, we know what we've got to do, we know what the losses are, and we know that with pretty simple steps ... that investment will be returned."
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