Extreme rainfall on the rise, is climate change to blame?

Jan 3, 2013

2012 was the second-wettest year in Britain since records began in 1910

BRITAIN endured its second wettest year on record in 2012 and the Met Office has warned that "extreme rainfall" is becoming more frequent, something that could be connected to climate change.

Although the first few months of last year were dry, the rest of 2012 was a washout, and by the end of December the total rainfall stood at 1330.7mm, just 6.6mm off the record set in 2000. Four of the five wettest years since records began in 1910 have occurred since the turn of the century.

"Changes in sea surface temperatures because of decreasing Arctic sea ice is one possible cause for the changes in weather patterns," reports the Daily Telegraph. "Another possibility is that a 0.7C increase in global air temperatures since pre-industrial times has led to a four per cent increase in moisture in the atmosphere, bringing with it a greater potential for heavy rain."

The Daily Mail said that torrential rain is on the increase and "climate change is probably the cause". It says that in the 1960s extreme rain would fall once every 125 days, but now it is more like once every 75 days. In 2012 such events happened every 70 days.

Sustainability website Blue & Green Tomorrow says that the phenomenon of extreme rainfall is a global one but Britain could be affected more than other countries because of the importance of the Gulf Stream, which carries warm air across the Atlantic, to its weather. "This geographic position makes us vulnerable to erratic weather patterns based on climate change," explained founder Simon Leadbetter.

The Met Office has trod carefully around the issue of climate change, but chief scientist Julia Slingo warned: "The trend towards more extreme rainfall events is one we are seeing around the world, in countries such as India and China, and now potentially here in the UK. Much more research is needed to understand more about the causes and potential implications.

"It's essential we look at how this may impact our rainfall patterns going forward over the next decade and beyond, so we can advise on the frequency of extreme weather in the future and the potential for more surface and river flooding. This will help inform decision-making about the need for future resilience both here in the UK and globally."

One issue relates to water storage. Sky News pointed out that much of the rain this year fell on saturated ground and simply ran away, while reservoirs ran low prior to the wet weather. It reports that there have been calls for better storage facilities to "harvest rainfall more efficiently and stop a repeat of last year's hosepipe bans".

Michael Norton from the Institute of Civil Engineers explained: "What is becoming obvious is that we're not storing enough water to be more resilient during the drought periods, which probably means we all need to be prepared to pay a little more for our water."

That thought was echoed by floods minister Owen Paterson, who told Sky News: "I think there is a case for building more reservoirs."

However The Guardian was critical of the government and claims "the coalition cut spending on flood defences by more than 25 per cent in the year it entered office".

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