Are the floods man-made?

If we were looking to stoke our national obsession with the weather there would be no shortage of kindling at the moment.

Swathes of the country are under water as Britain battles its worst floods in modern history - with scenes we are more used to seeing on television from far-off countries than in our own back yard.

It must be heartbreaking for communities mopping up just in time for a fresh deluge to do even more damage, and equally distressing for those left cut-off by the rising water with dwindling supplies and no power.

But, even in the midst of the chaos, the question on many people's lips is 'why?'

We have been warned over and again that man-made climate change will lead to wetter winters and hotter summers, however, lately, this seems to have turned on its head.

John Law, a WeatherQuest forecaster based at UEA in Norwich, said: “High pressure normally comes across us at this time of year, making for more settled weather, but it has gone further south this time.”

This has led to hot air, laden with moisture, being blown towards Britain which then collided with a cold weather system from the Atlantic, sparking the downpours.

Mr Law added: “We will have some good days in this area for the rest of the week. Today, for example, there will be still be one or two showers but also some good spells of sunshine, with temperatures of 21/22C.”

The rest of the country might not be so lucky.

Records show June was a record- breaking month for high rainfall in Norfolk - the second in a row - and in Norwich since records began in 1836.

Most places had 100mm to 200mm, with the driest falling marginally short of 100mm and the wettest surpassing 200mm.

Although, in this area, we have not seen the sort of damage the likes of Gloucestershire is experiencing, the wet weather is having a detrimental affect.

Only last month, the EDP reported that flooding has wiped out this year's nesting season for some of Britain's rarest wading birds.

Up to 1,000 pairs of waders and ground-nesting birds have lost their eggs or newly-hatched chicks on the Ouse Washes on the Norfolk/ Cambridgeshire border.

And this month we reported that freak weather is threatening the unique habitat of the Broads. The recent prolonged heavy rainfall means the water is as high today as it was at any time during the winter, leading to vital management work having to be abandoned by staff and an uncertain future for plants, insects and animals.

Marcus Armes, from the Norfolk-born CRed carbon reduction campaign, said it was hard to pin individual events on climate change but it was clearly an issue.

“While it can be foolish to attribute single weather events to man-made climate change, the increase in extreme events, such as the flooding we are currently experiencing, has been predicted by many climate scientists in numerous papers and journals over the last two decades,” he said.

“Obviously this means we need to plan now for more flooding, more droughts and more damage from gales.

“However, if we are to mitigate the worst weather impacts we need to address the cause of climate change as well as treat the symptoms. This means running carbon reduction measures alongside action to reduce the social, structural and financial damage caused by climate change.”

The latest floods coincide with a new report that says for the first time, climate scientists - including one from UEA - have clearly detected the human fingerprint on changing global precipitation patterns over the past century.

Set to be published in the science journal Nature on Thursday, Detection of Human Influence on 20th-Century Precipitation Trends breaks new ground in climate change research.

Dr Nathan Gillett, a lecturer at the UEA climatic research unit, said: “The simplest way to explain it is, on warm days your washing dries quicker because warmer weather holds more water but this also means more rain can come out of it.

“Man made climate change is caused by increasing greenhouse gases which warms the planet.”

The study demonstrates that human activities have contributed significantly to shifts in global precipitation patterns over the past century, including increased rain and snowfall in northern regions, drier conditions in tropical areas north of the equator, and increased rainfall in the southern tropics.

The scientists studied the combined effect that changes in greenhouse gases and sulphate aerosol concentrations in the atmosphere have had on global precipitation over land during the past century.

Greenhouse gases and sulphate aerosols are produced primarily by burning fossil fuels.

In the past century, climate records indicate there have been sizeable shifts in precipitation patterns around the globe.

Looking at average conditions over broad regions of the globe, and comparing them to changes anticipated due to human influence on climate, scientists have determined that human-induced climate change has caused most of the observed increase in precipitation north of 50 degrees latitude, a region that includes Canada, Russia and Europe, as well as in the southern hemisphere.

Human-induced climate change has also made important contributions to the drying observed in a broad region north of the equator that includes Mexico, Central America and northern Africa.

These shifts may have already had significant effects on ecosystems, agriculture and human health, especially in regions that are sensitive to changes in precipitation, such as the Sahel region in northern Africa.

The evidence suggests that natural factors, such as volcanic activity, have also contributed to the changes in global precipitation patterns over the past century, although to a much smaller extent than human activity.

The study compared observed precipitation changes with those produced by complex computer climate models that were used to estimate the effects of human activities over the past century.

It adds up to a worrying situation and extreme weather, such as flooding, seems like something we will have to get used to and plan for where possible.