Experts warn of more 'catastrophic' floods

Scientists warned Britain would have to brace itself for more catastrophic weather in years to come as global warming disrupts rainfall patterns. At least four people died and thousands of homes and businesses suffered damage and disruption as a result of this week's floods.

Of course, no-one can say for certain whether the record-breaking wet June the UK has just experienced is a direct result of climate change. However, experts agree that intense rain storms and flooding, producing the effects witnessed this month, are likely to become more frequent as temperatures rise.

Dr Dave Reay, from the School of GeoSciences, University of Edinburgh, predicted that the problem would become increasingly costly unless it is properly addressed.

He said: "The numbers are stark. Today there are an estimated 1.8 million homes in England and Wales at risk of flooding, and climate change will put more and more homes at risk. If we fail to address climate change then, by the year 2075, flooding could be costing us an extra £1 billion a year."

Natural variability

Similar warnings were sounded by other scientists. Professor Bob Spicer, from the Open University, said: "Basically the events we have seen over the past month and in particular the last 48 hours are typical of the kinds of things we can expect more of in the future.

"A warmer world leads to more evaporation, but also more rainfall, and the storm systems associated with a warmer atmosphere produce heavy downpours." He added that urban developers should realise that confining river channels and concreting over absorbent land surfaces contributed to flood risk.

Dr Kevin Hiscock, a hydrology expert from the University of East Anglia, said: "The current situation in northern and central England exposes the possible threat of flooding under climate change and our ability to adapt.

"Storm water drainage systems in our older cities may not be able to cope with increased rainfall intensities and what we have witnessed in Sheffield recently and previously in Boscastle in 2004 and Carlisle in 2005 suggest that we need to improve our flood defences and drainage infrastructure."

Professor Howard Wheater, from the Department of Civil and Environmental Engineering at Imperial College London, added: "The recent floods are an unusual combination of intense rainfall following a sequence of events that have wetted up the catchments.

"Is this a symptom of climate change? Maybe. We expect climate change to lead to more intense rainfall, and there is evidence that short duration rainfalls have become more intense over the last 30 years. However, extreme events are expected to occur due to natural climate variability."

Weather forecast

Weather experts said the excessive June rainfall was the result of a sluggish jet stream, a series of areas of low pressure, and "the time of year."

Forecasters predict more rain is still to come later this week and over the weekend. "Waves" in the jet stream which moves weather systems across Britain mean areas of low pressure have lasted longer and created far more rain than normal, according to Paul Knightley.

The forecaster for MeteoGroup UK, explained that the jet stream usually pulls weather systems along but because it was not sitting straight, it had been holding the low pressure in place.

He said: "Instead of the jet stream blowing straight from the Atlantic across the UK through Scandinavia, it has got huge waves in it. In a way it is like a rope which is not nice and straight but has kinks in it, making it move right down to the south and then back up to the north.

"Anything that gets caught by the weather does not have the jet stream to move it along and gets held up in the loop. When the jet stream doesn't push weather systems along, that causes rain and thunderstorms."

He added that at this time of year, when there was a lot of warmth and moisture in the air compared to the winter, there was more "fuel" for the weather to work with.