(Bloomberg) -- The heavy downpours seen in the UK and Ireland last fall and winter were about 20% worse because of climate change, a new scientific report found.

The region saw as many as 14 severe storms between October and March, flooding almost 7,000 homes and businesses, killing at least 13 people, damaging crops and causing power cuts. Babet, Ciarán, Henk and Isha were some of the most destructive storms in Ireland and the UK.

The World Weather Attribution group said in a study on Wednesday that rainfall in these storms was 20% more intense than it would have been if the world hadn’t already warmed by 1.2C since pre-industrial times. It was the second wettest storm season in the UK since records began, it said.

Such intense storm rainfall would only happen every 50 years in a preindustrial climate. But now it happens every five years. If temperature rises reach 2C by the 2040s or 2050s, those storms would be happening every three years, the report found.

Global warming causes extreme rainfall because a warmer atmosphere can hold more water vapor, so storm systems pick up extra water as they travel across the ocean. 

“The seemingly never ending rainfall this autumn and winter across the UK and Ireland had notable impacts across the two countries,” said Mark McCarthy, science manager of climate attribution at the UK’s Met Office.

“In the future we can expect further increases in frequency of wet autumns and winters. That’s why it is so important for us to adapt to our changing climate and become more resilient to increases in rainfall.”

Without better adaptation or more efforts to cut emissions, homes and businesses are likely to struggle to recover from the impacts of storms. The Association of British Insurers said weather-related home insurance claims in the UK rose by more than a third to a record £573 million during the season. 

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