Unprecedented’ storms and floods are more common than we think
By Paul Homewood
h/t Kelvin Vaughan
http://phys.org/news/2015-12-unprecedented-storms-common.html
A touch of commonsense from Phys.Org:
The recent ‘unprecedented’ flooding in north-west England might be more common than currently believed, a group of scientists has warned.
A team of experts from the Universities of Aberystwyth, Cambridge and Glasgow have drawn on historic records to build a clearer picture of the flooding.
They conclude that 21st-century flood events such as Storm Desmond are not exceptional or unprecedented in terms of their frequency or magnitude, and that flood frequency and flood risk forecasts would be improved by including data from flood deposits dating back hundreds of years.
Dr Tom Spencer from the University of Cambridge said: "In the House of Commons on Monday (December 7), the Environment Secretary called the flooding in north-west England ‘unprecedented’ and ‘consistent with climate change trends’. But is this actually true?
"Conventional methods of analysing river flow gauge records cannot answer these questions because upland catchments usually have no or very short records of water levels of around 30 or 40 years. In fact, recent careful scientific analysis of palaeoflood deposits (flood deposits dating back hundreds of years) in the UK uplands shows that 21st-century floods are not unprecedented in terms of both their frequency (they were more frequent before 1960) and magnitude (the biggest events occurred during the 17th–19th centuries)."
Professor Mark Macklin, an expert in river flooding and climate change impacts at Aberystwyth University, said: "UK documentary records and old flood deposits dating back hundreds of years indicate that these floods are not unprecedented, which means we are grossly underestimating flood risk and endangering peoples’ lives.
"In some areas, recent floods have either equalled or exceeded the largest recorded events and these incidences can be ascribed to climate variability in Atlantic margin weather systems.
"It is of concern that historical data suggests there is far more capacity in the North Atlantic climate system to produce wetter and more prolonged flood-rich periods than hitherto experienced in the 21st century. Looking forward, an increased likelihood of weather extremes due to climate change means that extending our flood record using geomorphology science must be placed at the centre of flood risk assessment in the UK."
Professor Macklin suggests that new approaches to flood risk analysis be adopted to include instrumental, documentary and most importantly palaeoflood records.
He added: "Current approaches using flood frequency analysis and flood risk assessment based on 40-50 year long flow records are far shorter than the design life of most engineering structures and strategic flood risk planning approaches. They are not fit for purpose now, let alone in a changing climate."
Professor John Lewin from the University of Aberystwyth said: "What is needed, is far more resilience for already-developed floodplains, and much more serious insistence that future floodplain development should be virtually curtailed. Somewhere along the line floodplain development has been allowed by local authorities and the UK government to continue regardless."
Dr Larissa Naylor from the University of Glasgow said: "These floods and the 2013/14 storms have shown us that our landscape is dynamic rather than static – where rivers reshape floodplains and erosion remodels our coastline – with large economic and social costs. We need to urgently consider how we plan our cities and towns, and rebuild in the wake of large flood and storm events, to live safely in our changing landscape."
Spencer, Lewin, Macklin and Naylor are members of the British Society for Geomorphology’s Working Group on Stormy Geomorphology, who are currently finalising a global state-of-the-art analysis of the role geomorphology science can play in an age of extremes in the Wiley journal Earth Surface Processes and Landforms.
Many of us have saying this for a long time!
Comments are closed.
NOT A LOT OF PEOPLE KNOW THAT 
Reblogged this on Wolsten and commented:
This helps to explain why politicians promote climate change alarmism. How convenient to be able to blame the climate bogey man for their own failure to protect the people they serve.
I strongly agree with the idea that many events may not be mentioned because of different reasons from lack of knowledge to political ones, for example. And, since you brought that subject into discussion, here’a a related topic: resultant rain due to war. It’s a subject that was analysed and quoted by few scientists. It seems that the suddenness and extreme of the war winter of1939/40 had been such an extraordinary meteorological event that every aspect relating toits rapid build up should be elaborated and weighed. The atmosphere during the particularly climatically sensitive autumn months of September to December in the Northern Hemisphere reacted immediately. Rain thatcame down in Western Europe as heavy down poursince the war had started on September 1st had not been available in the USA during the corresponding period. While mostly excessive rain occurred in Europe in October, four weeks later the USA experienced a record dry month with only 44% precipitation of average for the whole country during November 1939: http://www.2030climate.com/a2005/02_31-Dateien/02_31.html.
The winter of 1939-1940 was in a period known as “The Phoney War” Wiki says
At the same time the Nazi-Soviet nonaggression pact was in operation. So are you saying that the climate anticipated the Blitzkrieg of May 1940? To me it seems much more likely a natural climate event.
Can you kindly define „Phoney War“. Up to three million soldiers “worked’ along the Maginot Line/Westwall, with many thousands of motorized vehicles, bomber and fighter planes, and guns. Until the end of December 1939 more than 100.000 sea mines were laid, 150 Allies merchant ships sunk, and so on, a.s.o.; calling the breakdown of weather in Europe since mid-December 1939 a “natural climate event”, is ignorance of facts.
We often seem to hear the phrase ‘this was supposed to be a 1 in 100 year event…and now it’s happened twice in 5 years…climate change’!!
Yet all that does is prove the person / organisation that predicted such an event as a ‘1 in 100 year’ event was wrong!
Not necessarily. It can happen 3 times in a decade and still be a one in 100 year event. We’d need to look at it over 500+ years to judge whether they were right or wrong. But, the point is taken – 1 in 100 is just a (slightly) educated and politically-constrained guess.
The point I was getting at is they use such terms to imply their wondrous knowledge is ‘fact’. It’s classic projection. But when an event occurs again then by definition it disproves their original assertion and reveals their ‘factual’ claim to be erroneous.
The weather isn’t ‘wrong’, they are.
I am away from my desktop at present so can’t find the bookmark easily, but about 7 years ago a researcher at Durham University found that there is an underlying 50 to 60 year cycle which features wetter “decades” on that cycle. 1897/98, 1950s, 2010s fit that pattern? He stated that we had become habituated to believing that the drier decades of the second half of the 20th century were “normal” and planned on it. These researchers in this article seem to be telling us the same.
Here Dave
Reblogged this on WeatherAction News.
About 2 years ago I read a statement by an OZ prof at an engineering school (I think) on the topic of flood frequency. [I have also seen something similar for the western USA.]
Weather records and stream flow records were first completed when the data had been collected during favorable, that is “wet” but not extreme, years. The fellow from Australia argued that the 1-in-50 or 1-in-100 sort of numbers were biased and needed to be done anew. I think part of the issue was assuming a normal distribution when such was not the case.
A friend is working on charcoal and pollen in lake sediments to recreate a fire-history going back hundreds of years. Same sorts of reasons apply.
hooked on charcoal
These “experts” are not Climate Scientists and obviously funded by the fossil fuel industry.
(sarc)
It seems that in any academic writings on this kind of subject the phrase “climate change” has to be shoehorned in somewhere. The overall thrust of the piece is that there is nothing unusual about flooding events and that they have been going on for hundreds of years, meaning that, in this respect, climate is staying pretty much the same, not changing in fact.
Exactly right. The mention of climate change is gratuitous. Seems a very sensible piece. I particularly noted this bit –
“historical data suggests there is far more capacity in the North Atlantic climate
system to produce wetter and more prolonged flood-rich periods than hitherto
experienced in the 21st century.”
Anyone who knows the Lake District won’t be surprised: but if it happens we can expect it to co-opted as evidence of extreme AGW weather, like it or not.
mothcatcher,
More than gratuitous –
“Looking forward, an increased likelihood of weather extremes due to climate change…..”.
Even the IPCC aren’t saying that – he’s making stuff up.
After some green research dosh are we Prof. Macklin ?
Like all things climatological, if we had accurate data over very long periods of time there wouldn’t be any argument. Alas we don’t. The future appears that much sadder due to homogenisation of the relatively small amount of data we do have.
To extrapolate out from these recent weather events to be evidence of man-made climate change shows that Dr Tom Spencer has abandoned both logic, and scientific thinking. His comment is evidence of the general declined in thinking logically and scientifically by government bought, or hired-in, scientists. Such newly minted bureaucrats will only voice the answers that their politics dictate, with all the assurances of a snake-oil salesman.
Dr Tom Spencer has instead shown typical lazy bureaucrat’s thinking in that events that have not happen in a living person’s lifetime are now defined as ‘unprecedented’, and these events are inconsistent with natural (or normal) climate variation. He is wrong in both cases. Maybe he should return to his standard fare of hyperventilating about Venice (see http://www.geog.cam.ac.uk/research/projects/venice2003/programme.pdf) where he displays a more artistic misunderstanding.
“Consistent with climate change” is one of those meaningless phrases that people with nothing to say can use when they have nothing to say. What the alarmists predicted for the UK was a hotter drier climate, drought was predicted as being a problem. When we actually got the precise opposite of what they had predicted, consistent with climate change was the get out clause of choice. Maybe I should use this one when I next have a day out at the races, my horse coming in last was consistent with it winning.
“Those who do not learn from history are doomed to repeat it” (George Santayana). Maybe Ms Slingo should have that on her office wall!