The record-breaking rainfall and devastating floods that have drenched Scotland over the last few weeks are the “new normal” – and they could force some communities to abandon built-up areas and move to higher ground.

Experts canvassed by the Sunday Herald warn that we will have to get used to more winters like this one, as climate pollution from vehicles and industry warms the globe and wreaks havoc with the weather. Without action to curb carbon emissions, they say, it is likely to get much worse.

“There is no natural weather any more,” declared Professor James Curran, the former chief executive of the Scottish Environment Protection Agency and a leading climate expert. “The world is now warmer by one degree centigrade than it would be without climate change – so there is no weather anywhere, at any time, that isn’t man-made these days.”

It was wasting time to endlessly debate to what extent the current bad weather was caused by climate pollution, he argued. After last month’s climate summit in Paris, the priority was to tackle the problem.

“It’s been long predicted and is almost certain now that, whatever we do, flooding both from the sea and from rivers will become more severe and at least twice as frequent by 2100,” he said.

He urged decision-makers to look urgently at how we manage our hills, forests, moors, wetlands, fields and flood plains. “The last resort should be to build concrete walls but they’ll be necessary as well - although, eventually, we may also need to abandon some built-up areas and relocate.”

What most worries Curran is the summertime melting of the Greenland icecap, which creates a big north-south temperature difference in the Atlantic to the west of Scotland. “This creates and drives ever more powerful storms onto our shores – producing gales and driving rain,” he said.

“It’s no coincidence that we’ve moved from prodigious flooding straight into sleet and snow,” he added. “Our weather is getting increasingly variable and severe.”

Many scientists now agree that global warming is at least partly to blame for the floods – something that they wouldn’t have said a few years ago. They point out that warmer air holds more moisture, which then falls as rain.

The point was forcibly made yesterday by Professor Alan Jenkins, deputy director of the UK’s leading flood research body, the Centre for Ecology and Hydrology. “We are absolutely convinced that there is weighty scientific evidence that the recent extreme rainfall has been impacted by climate change,” he said.

A study by researchers at the University of Oxford analysed links between global warming and storm Desmond in December. It concluded that heavy rain is now 40 per cent more likely than it was in the past.

According to Simon Tett, professor of earth system dynamics at the University of Edinburgh, said changes are happening faster than anticipated. “We have long expected winters in the northern hemisphere to be wetter, and for rainfall to be more intense,” he said.

“As humans have increased carbon dioxide in the atmosphere and warmed the planet, rainfall amount and intensity have, indeed, increased - and by more than we predicted.”

Tett thinks there’s been an important change since the start of the millennium. “My impression is that there has been a significant shift since 2000, and we now have a new UK climate, a new normal,” he told the Sunday Herald.

“I worry this means more rain and an increased risk of floods for many communities in Scotland. That is something which the Scottish Government should respond too.”

December was by far the wettest Scotland has seen since records began over a century ago in 1910, with more than twice the average amount of rain. Some 50 of the river gauges run by the Scottish Environment Protection Agency for decades measured record levels.

Environmental groups warned that this was just the start, unless the world got serious about cutting climate pollution. “The scale of flood-related damage we've just witnessed will pale into insignificance when compared to the devastation that we can expect in the future if we fail to properly address climate change,” said Lang Banks, the director of WWF Scotland.

"Reducing the risk of flooding is yet another reason why, as we approach the Holyrood elections, we need to see every one of the political parties make clear their plans to ensure Scotland meets its climate change targets."

Dr Richard Dixon, director of Friends of the Earth Scotland, argued that communities would need protecting from much bigger floods in the future. “This period of terrible flooding could be the norm in a few decades if the world does not reduce climate emissions very rapidly,” he said.

According to a report for the Scottish Government last month, 108,000 homes in Scotland are at risk of flooding. Ministers said that climate change was increasing the dangers.

Tomorrow, ministers are due to announce a new “flood risk management strategy”.

Such moves will be welcomed. But whether they will be enough to cope with the “new normal” and the floods of the future, only time will tell.


Scotland’s record-breaking rain

- December 2015 was by far the wettest Scotland has seen since records began in 1910, with 351.4mm of rain.

- Scotland’s second wettest December was in 2013, with 300.7mm of rain.

- Average rainfall in Scotland for December between 1981 and 2010 was 153.5mm.

- 50 of the river gauges run by the Scottish Environment Protection Agency (Sepa) for decades measured record levels in December.

- Six of Sepa’s river gauges in northeast Scotland have measured record levels in January.

- At 7am on Friday last week the River Don just upstream of Aberdeen reached a peak over 1.3m higher than any levels recorded since 1988.