Intense floods and storms around the world could double in frequency within 13 years, as climate breakdown and socioeconomic factors combine, according to a new study.

The authors of the analysis say it’s the first to incorporate historical local and global climate data and information about population density, income and poverty to estimate how many hard-hitting disasters to expect. They counted floods and storms that would affect 1,000 people or kill 100 people.

Broadly, the researchers also see governments around the world as critically unprepared. The authors found very high risks for countries such as Australia, Bangladesh and China. Risks are highest for countries that are already seeing far more extreme events than the global average.

The study is published in the peer-reviewed Climate, Disaster and Development Journal.

Co-author Vinod Thomas, a visiting professor at the Asian Institute of Management in Manila who has held senior posts at the World Bank, said policymakers for the most part do not yet incorporate climate effects into their preparedness efforts.

“On the one side, there needs to be climate adaptation efforts, such as relocating people from highly exposed coastal regions or building better disaster preparedness that would withstand extreme hurricanes,” Thomas said. “Equally, there is a strong case for stepping up climate change mitigation in decarbonizing their economies.”

Thomas said the findings of an “unmistakable causal link between carbon emissions and more intense floods and storms come at a crucial time,” as forest fires burn through Australia and floods and powerful storms hit the US and Europe.

He said countries like Thailand, which saw massive flooding events that killed hundreds and affected millions in 2011, could not handle twice as many catastrophes each year. He said they need to conduct stress tests to understand what they can withstand.

The study examined how disasters have increased as greenhouse gases have accumulated in the atmosphere over 60 years. It then projected that same trend into the future and considered how much a continued increase in floods and storms would affect regions based on how populous they are and whether residents are financially secure and prepared for disasters.

The research used an economic approach, rather than relying on climate modeling – which uses computers to calculate likely outcomes based on a range of inputs.

The journal publishing the study is based in Manila and not widely known. The authors said they first attempted to publish their work in the well-read journal Science.

Don Wuebbles, a professor of atmosphere sciences at the University of Illinois who worked on the 2018 US National Climate Assessment, said the study might be underestimating future disasters by assuming disasters will continue to increase at the current rate.

He said he appreciated that the researchers considered population growth and density but that he was “not sure they adequately considered the changes in climate for the future”.

Ramón López, the lead author of the study who is a professor at the University of Chile, acknowledged the methods used might not account for the likelihood that severe events will increase at a faster rate than we have seen in the past.