Devastating storms in Europe, which cost insurers €1 billion ($1.63 billion) in January, may be more common in the future, according to Swiss Re.

Winter storm Erwin, which caused insured losses of about €900 million ($1.47 billion) in the Scandinavian countries, was an example of what to expect, the reinsurer said.

The return period for a storm on this scale is 20 years. The return period of winter storm Anatol in December 1999 – which resulted in a loss for the insurance industry of €1.9 billion ($3.1 billion) – is about 70 years.

Are the major storms being experienced with seemingly greater intensity around the world being caused by global warming? Scientific opinion is divided, but the Los Angeles Times says recent research indicates that over the past 50 years the intensity of Atlantic Ocean storms – which can lead to hurricanes – has increased by 50%.

The National Oceanic and Atmosphere Administration recently raised its tropical storms forecast for this year from 18 to 21, with 11 becoming hurricanes and as many as seven reaching “major” status. The LA Times says a typical storm year in the Atlantic results in six hurricanes. 

Most established scientific opinion – and the agency – is based on the belief this is not a result of global warming, but “the result of a confluence of cyclical ocean and atmospheric conditions that tend to produce heightened tropical storms every 20 to 30 years”.