The cost of natural disasters in Australia is now predicted to soar way beyond previous estimates, and the message is simple: we must do more to prepare.

The Australian Business Roundtable for Disaster Resilience & Safer Communities has published two new reports: The Economic Cost of the Social Impact of Natural Disasters, and Building Resilient Infrastructure.

The roundtable – comprising the CEOs of IAG, Munich Re, Australian Red Cross, Investa Office, Optus and Westpac – was formed in 2012 to champion a co-ordinated national approach on resilience.

Its latest reports, compiled by Deloitte Access Economics, don’t hold back, revealing social devastation and impacts to infrastructure can be the longest-lasting and most significant consequences of disasters.

The first report takes into account, for the first time, the cost of social impacts such as mental health issues, family violence, chronic disease and alcohol misuse.

Under this model, the total cost of natural disasters in Australia is expected to rise from $9 billion to $33 billion by 2050 – at least 50% more than previously estimated.

“Deloitte’s modelling showed last year’s spate of natural disasters left a damage bill of more than $9 billion, which was about 0.6% of our GDP, and this is expected to double by 2030,” Australian Red Cross Director of Australian Services Noel Clement said.

“Governments, business and communities need to work together to address the medium and long-term social impacts of natural disasters through further investment and research into community resilience programs.”

Highlighting three case studies – the 2010/11 Queensland floods, Victoria’s Black Saturday bushfires in 2009 and the 1989 Newcastle earthquake – the report estimates social costs are equal to, if not higher than, losses such as property destruction.

The findings are “conservative at best”, it declares.

The report recommends pre and post-disaster funding that better reflects the long-term nature of social impacts, and a collaborative approach involving government, business, non-profit groups and communities.

The Building Resilient Infrastructure report says $17 billion will need to be spent by 2050 on direct replacement of disaster-hit critical assets such as roads, railways and hospitals.

Australian governments spent more than $450 million each financial year restoring public infrastructure following extreme weather between 2002/03 and 2010/11.

The report recommends infrastructure planning processes integrate resilience in government and industry decision-making, and that incentives be improved through policy change and funding arrangements.

The roundtable reports tie in with the findings of the Northern Australia Insurance Premiums Taskforce final report, released on Friday by Assistant Treasurer Kelly O’Dwyer.

The report backs mitigation over government intervention in the form of a reinsurance pool or mutual.

IAG MD and CEO Peter Harmer says the nation has a social obligation to help communities feel safer and recover more quickly.

“It’s in the national interest for government and businesses to work together with our communities to achieve this by focusing more on prevention,” he said. “This means investing more upfront in openly sharing data, building resilient infrastructure and creating stronger and better-prepared communities.”

Munich Re CEO Heinrich Eder says Australia faces extremely high risk from disasters such as cyclones, drought and storms.

“This is why building resilience is so important to all Australians,” he said. “The new normal is to expect the unexpected.

“We know storms are becoming more frequent and big population centres such as Brisbane face new and heightened risks.”

More research is needed, the roundtable says.

However, one thing that’s well known already is that greater investment in resilience will be required.

It’s never easy convincing authorities to part with cash, but if Australia doesn’t prepare now, the country will pay a much heavier price later.