Natural catastrophes and man-made disasters caused economic losses of $US186 billion ($177.91 billion) last year, according to Swiss Re’s latest Sigma study.

Major weather events in the US led to 14,000 deaths and insured losses of $US77 billion ($73.65 billion), making it the third most costly year on record.

Nine of the 10 most expensive insured loss events were in the US, with Superstorm Sandy topping the table for insured and economic losses.

Sandy caused insured losses of about $US35 billion ($33.48 billion) and about $US70 billion ($66.96 billion) of economic losses, making it the second most damaging windstorm on record after Hurricane Katrina in 2005.

“Sandy challenged the industry with its combination of record wind field and storm surge,” Swiss Re Group Chief Underwriting Officer Matthias Weber said.

“The possibility that such events could increase in frequency and strike densely populated regions such as the northeast US means extreme storm surges need to be more thoroughly understood.”

The study features a simulation showing how a 25cm rise in sea level by 2050 will almost double the probability of extreme flood losses.

A $US20 billion ($19.13 billion) insured loss event, now expected once in 250 years, would be expected once in 140 years.

Record heat and extremely dry conditions in the US led to one of the worst droughts in decades, affecting more than half of the country, the study says.

Severe crop failures in the US Corn Belt led to insured agricultural losses of $US11 billion ($10.52 billion).

A rare, and relatively weak, series of earthquakes in north Italy caused insured losses of $US1.6 billion ($1.53 billion) and economic losses of $US16 billion ($15.3 billion).

Last year’s losses were significantly lower than in 2011, when earthquakes and flooding in the Asia-Pacific region caused record insured losses of more than $US126 billion ($120.52 billion).