Climate change brings one-in-three chance of record rainfall, warns Met Office

There is now a one-in-three chance of record rainfall hitting part of England and Wales each winter, according to new Met Office study which highlights the risk of major flooding as the climate warms.

The researchers warned that global warming would change the risk of extreme weather and suggested politicians should bear this in mind when planning to protect the public, businesses and infrastructure.

A series of storms in the winter of 2013-14 caused widespread flooding and about £1bn-worth of damage in the Thames river valley.

Writing in the journal Nature Communications, the Met Office team said they had used computer models of the climate to show that those storms “could have been anticipated”.

They also found “in the current climate” there was “a high chance of exceeding the observed record monthly rainfall totals in many regions of the UK”.

“In south-east England there is a 7 per cent chance of exceeding the current rainfall record in at least one month in any given winter,” the scientists said.

“Expanding our analysis to some other regions of England and Wales the risk increases to a 34 per cent chance of breaking a regional record somewhere each winter.”

The researchers, led by Dr Vikki Thompson, added that these estimates of the risks were “only valid in the current climate”.

“Future climate change is likely to alter the chances of extremes,” they wrote. “This is a significant risk and could be used to inform decision makers on the likelihood and intensity of unprecedented rainfall events in the near future to protect the public, business and infrastructure from extreme rainfall and flooding.”

Commenting on the new research, Professor Len Shaffrey, of Reading University, said it provided “some really interesting insights into the probability of extreme rainfall events such as the winter of 2013-14 and how risks might be changing due to climate change”.

“Using weather and climate models to better understand the probability of extreme weather is an important method that is becoming more widely used to help inform those dealing with weather impacts about the risks of extreme events,” he said.

“Future research needs to evaluate how well weather and climate models are able to accurately simulate other extreme weather events, for example droughts and heat waves, if we want to use models to better understand extreme weather risks and how they might be changing.”

Bob Ward, policy and communications director at the Grantham Research Institute on Climate Change and the Environment in London, urged Michael Gove, the Environment Secretary, to “carefully read” the paper about the study.

“We know that the risk of record rainfall is increasing due to climate change. From 2000 onwards, the UK has experienced six of the seven wettest years since records began in 1910, and its eight warmest years,” he said.

“The period between January and June 2017 was the third warmest such period on record. As the atmosphere warms, it can hold more water, increasing the risk of heavy rainfall.

“The UK’s two wettest winters on record occurred in 2013-14 and 2015-16, leading to flooding in many parts of the country, and highlighting to the Government that it had severely underestimated the risks.”

Daniel Johns, head of adaptation at the Government’s independent advisory body, the Committee on Climate Change, said the paper represented “important research”.

He added that it “reinforces our call for the Government to prepare for and expect a significant flood event to take place somewhere in the country almost every year”.

“However, it’s worth pointing out that the ‘current’ UK climate the paper refers to is not stable and will continue to change,” he said.

“As we set out in our evidence report for the 2017 UK Climate Change Risk Assessment, rainfall patterns in some UK regions have already intensified, as long predicted by climate models.

“A warmer atmosphere can hold more moisture, and evidence is mounting that higher seasonal temperatures, and heavier rainfall, are already affecting the UK.”