Global warming 'could cause more UK flash floods'

Climate change could mean that flash floods across the UK become more commonplace, according to a new study. Researchers from the University of Newcastle and the Met Office have suggested that the onset of global warming could result in a higher number of extreme downpours throughout the UK.

The study found that as atmospheric temperatures increase, Britain could be subjected to five times the number of "extreme rainfall events" per hour. This increases the risk for many areas that have previously been subjected to flash flooding.

However, more research could be needed into this, as the study was based upon a single computer model. Scientists will have to look into the possibility even more in order to accurately predict how climate change could affect flash flooding.

A number of models have been created in the past in an effort to understand how global warming could affect events such as flash flooding. However, they have never been good enough to provide a full account of how extreme levels of hourly rainfall could be affected by warmer temperatures.

In order to improve the computer model and get an accurate picture of how flash flooding could be affected by global warming, the researchers used grid spacings measuring 1.5 km rather than the normal 12 km grids. The Met Office's super computer was then used to run the simulations for nine months. In this time, the computer was only able to assess the risk to the southern half of Britain.

The model was used to assess up until the year 2100, based upon the high-end climate predictions made by the Intergovernmental Panel on Climate Change. It was found that both grid sizes - 1.5 km and 12 km - showed increased rainfall in line with climate projections. This included a significant rise in downpours of over 28 mm per hour, enough to result in flash flooding.

Flash floods have been a problem throughout the UK for a number of years, with one of the worst instances on record taking place in the Cornish village of Boscastle in 2004. In August around eight inches of rain fell within a four-hour period, resulting in a three metre high wall of water sweeping through the village and causing heavy damage.