Floods and droughts?
Discussion
turbobloke said:
UK floods are not linked to human-induced climate change . Apart from analysis demonstrating this from the UK Centre for Ecology & Hydrology (2007 SW UK event) and a team from Aberystwyth, Cambridge and Glasgow (2015 NW UK event) a research paper by J Barredo looked at a recent climatically relevant period, 37 years, and found no detectable sign of human-induced global climate change in flood events across 31 countries in Europe including the UK.
Where does the CEH report say this? CEH report actually says said:
"A number of major flood episodes in the early years of the 21st century has fuelled speculation that flood risk is increasing due to global warming. By their nature, however, any cluster of extreme hydrological events cannot readily be linked directly to climate change. The 2007 flooding was remarkable in its extent and severity, and truly outstanding for a summer event. It underlined the UK’s continuing vulnerability to climatic extremes but long-term rainfall and river flow records confirm the exceptional rarity of the hydrological conditions experienced in 2007. A synthesis of the rainfall and river flow evidence indicates that the summer was a very singular episode. The associated fluvial flooding does not constitute an element in any established hydrological trend or appear to form part of a pattern consistent with currently favoured climate change scenarios"
Carbon Brief also recently ran a piece on flooding and climate change in the UK (here: https://www.carbonbrief.org/guest-post-are-uk-floo... Interestingly, it's by the same co-author as the CEH report above.Carbon Brief said:
Research in the UK using very long flood records, such as for the Severn, above, points to pronounced variability between decades, leading to “flood rich” and “flood poor” periods driven by the NAO, AMO and a long list of other factors. These variations make it difficult to interpret trends, so we cannot yet say with confidence how much of the observed increase in flooding over recent decades is caused by human-caused warming, and how much is due to natural variability. However, as anthropogenic warming influences modes of ocean-atmosphere variability, such as the NAO, the increase in floods certainly reflects a combination of both.
What we can say with some certainty is that there has been an increasing trend in flooding over the past four or five decades in parts of northern and western Britain, and this is consistent with what we expect in a warming world.
What we can say with some certainty is that there has been an increasing trend in flooding over the past four or five decades in parts of northern and western Britain, and this is consistent with what we expect in a warming world.
LittleBigPlanet said:
turbobloke said:
UK floods are not linked to human-induced climate change . Apart from analysis demonstrating this from the UK Centre for Ecology & Hydrology (2007 SW UK event) and a team from Aberystwyth, Cambridge and Glasgow (2015 NW UK event) a research paper by J Barredo looked at a recent climatically relevant period, 37 years, and found no detectable sign of human-induced global climate change in flood events across 31 countries in Europe including the UK.
Where does the CEH report say this? CEH report actually says said:
"A number of major flood episodes in the early years of the 21st century has fuelled speculation that flood risk is increasing due to global warming. By their nature, however, any cluster of extreme hydrological events cannot readily be linked directly to climate change. The 2007 flooding was remarkable in its extent and severity, and truly outstanding for a summer event. It underlined the UK’s continuing vulnerability to climatic extremes but long-term rainfall and river flow records confirm the exceptional rarity of the hydrological conditions experienced in 2007. A synthesis of the rainfall and river flow evidence indicates that the summer was a very singular episode. The associated fluvial flooding does not constitute an element in any established hydrological trend or appear to form part of a pattern consistent with currently favoured climate change scenarios"
Carbon Brief also recently ran a piece on flooding and climate change in the UK (here: https://www.carbonbrief.org/guest-post-are-uk-floo... Interestingly, it's by the same co-author as the CEH report above.Carbon Brief said:
Research in the UK using very long flood records, such as for the Severn, above, points to pronounced variability between decades, leading to “flood rich” and “flood poor” periods driven by the NAO, AMO and a long list of other factors. These variations make it difficult to interpret trends, so we cannot yet say with confidence how much of the observed increase in flooding over recent decades is caused by human-caused warming, and how much is due to natural variability. However, as anthropogenic warming influences modes of ocean-atmosphere variability, such as the NAO, the increase in floods certainly reflects a combination of both.
What we can say with some certainty is that there has been an increasing trend in flooding over the past four or five decades in parts of northern and western Britain, and this is consistent with what we expect in a warming world.
What we can say with some certainty is that there has been an increasing trend in flooding over the past four or five decades in parts of northern and western Britain, and this is consistent with what we expect in a warming world.
https://www.nature.com/articles/s41586-019-1495-6
(click on the Figures bit on this one to see where flood flows have changed)
https://www.hydrol-earth-syst-sci-discuss.net/hess...
https://link.springer.com/article/10.1007%2Fs10584...
https://www.nature.com/articles/nclimate2927
Edited by Lotus 50 on Friday 21st February 16:40
Edited by Lotus 50 on Friday 21st February 16:42
Borghetto said:
Try this link https://riverlevels.uk/
That does not really answer my question which is more about the aquifer or water table and reservoirs.The rivers can be high over a short term which may or may not saturate everywhere and I guess where the flooding is is not high up above the reservoirs.
Lotus 50 said:
There's also other papers that say the opposite to TB, the following are a few that came up following a quick inter web search...
https://www.nature.com/articles/s41586-019-1495-6
(click on the Figures bit on this one to see where flood flows have changed)
https://www.hydrol-earth-syst-sci-discuss.net/hess...
https://link.springer.com/article/10.1007%2Fs10584...
https://www.nature.com/articles/nclimate2927
It's not what I say, it's what Barredo says, the UK Centre for Ecology and Hydrology says, and what the Aberystwyth / Cambridge / Glasgow team says, and others not cited. https://www.nature.com/articles/s41586-019-1495-6
(click on the Figures bit on this one to see where flood flows have changed)
https://www.hydrol-earth-syst-sci-discuss.net/hess...
https://link.springer.com/article/10.1007%2Fs10584...
https://www.nature.com/articles/nclimate2927
In terms of the Nature paper linked above, the detailed regional (European) losses are what they are; any causal link to climate change is assumed and the manmade nature of this is also assumed. This is assertion with no adequate consideration of natural variability (see below). No causality has been established, the existence of manmade climate change is taken for granted as the explanation.
The same assumptions are made in the abstract at the second link "here we provide an initial assessment of the influence of anthropogenic climate change" which clearly assumes anthropogenic climate change exists and is causal to the observations.
The third paper with Myles Allen as a co-author does the same. The final link speaks of "quantifying present-day effects of human influence on climate" once again as an assumed cause with no empirical evidence in support.
Centre for Ecology and Hydrology Lead Author Terry Marsh said:
The UK river floods of summer 2007 were a very singular episode, which does not form part of any clear historical trend or show consistency with currently favoured climate change scenarios. The exceptional river flooding fuelled speculation that flood risk is increasing due to global warming. Due to the inherent variability of the UK climate, any extreme hydrological event cannot readily be linked directly to climate change.
This is the major problem with attempts to assume causality. The papers listed are in effect, and I'm not saying deliberately, using a mix of assumption regarding causality, and opacity.
Terry Marsh also said:
Vulnerability to flooding has increased markedly as a consequence of floodplain development. This is despite increased resilience to flood risk through improved flood alleviation strategies and more sophisticated flood warning capabilities.
Talk about stating the obvious!As for the Aberystwyth / Cambridge / Glasgow team, they concluded that 21st-century flood events 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. This is the point I made in my original post, going back 200 years represents an inadequate cherry pick.
Dr Tom Spencer from the University of Cambridge said:
In the House of Commons, the Environment Secretary called the flooding in north-west England ‘unprecedented’ and ‘consistent with climate change trends’. But is this actually true?
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).
This is a simple test, lacking in complexity and opacity, which manmade climate change fails as a cause for recent flooding: in previous centuries (and decades) floods have been shown using empirical data to be worse than now in both frequency and magnitude, whereas carbon dioxide levels were significantly lower back then. This is the opposite to what would be expected from anthropogenic climate change due to carbon dioxide emissions.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).
As a final example of how logic is simply turned on its head to maintain climate change as a false explanation, climate models have shown that manmade climate change should cause the jet stream to weaken and move closer to the pole. However, in recent times where a sequence of storms. or a slow-moving storm, brought flooding to the UK, it was as a result of the jet stream strengthening not weakening, and moving away from the pole. Yet climate change is simply trotted out as 'the explanation' when it's not even consistent with its own predictions.
The manmade climate change explanation fails on all counts.
Prof Macklin said:
UK documentary records and old flood deposits dating back hundreds of years indicate that these (recent) floods are not unprecedented, which means we are grossly underestimating flood risk and endangering peoples’ lives.
As per my original post, spending tens and hundreds of $billions on unreliable renewables is not going to reduce the tragedy of lost lives and flooded homes/businesses. Less than that amount of money spent on adequate flood defences (rather than stupidly thinking we can spend it to control nature) would have a massively beneficial impact on people's lives where homes and businesses are most at risk.Getragdogleg said:
Local flooding here is caused by the unmaintained drains and gutters filling up with mud and leaves and then simply not working to actually drain water when we do get rain.
Its maintenance that is required.
Water shortages in summer are from too much demand and not enough maintenance on leaky pipes. Infrastructure investment is needed to enlarge or build reservoirs but again the money is not spent.
Same issues here (Richmond West London)Its maintenance that is required.
Water shortages in summer are from too much demand and not enough maintenance on leaky pipes. Infrastructure investment is needed to enlarge or build reservoirs but again the money is not spent.
Drive along the A316 the main dual carriageway into London from the M3.
It’s a disgrace, an absolute embarrassment. The gutters are deep with litter, silt, rubbish, leaves. The drains are completely covered with trash.
You’ll never see a road sweeper or drains being jetted.
Any rainfall ( needn’t be a downpour, there’s no more rain than 20 years ago) huge puddles cover the entire carriageway.
Richmond upon Thames has the title if “Royal Borough” it’s shameful and makes me despair for what we are doing to this country.
Edited by Thankyou4calling on Friday 21st February 19:50
My original comment was not really to do with why we seem to be getting floods in the winter, and allegedly droughts in the summer, but more to the fact that that is what we `seem' to be getting.
As posted earlier any scheme which seeks to divert some of the excess fresh water we get in the winter is not going to be anything else but colossally expensive, but when put against a possibly repeating pattern of damagingly expensive flooding, and flood repairs, and loss of crops through both flooding and droughts, it would seem to be common sense to spend a huge, sum now to build the infrastructure needed to store and distribute excess rain water, than repeatedly pay huge sums to counter the effects of flooding and possible droughts every year.
I remember someone in government suggesting that a huge North, South pipeline was built to bring water from the North where there always seems to be plenty / in some cases too much, to the South where droughts hit in the summer, which was met with a comment from someone in the North saying you`re not having oour water. Wonder if that person is still saying that now?
As posted earlier any scheme which seeks to divert some of the excess fresh water we get in the winter is not going to be anything else but colossally expensive, but when put against a possibly repeating pattern of damagingly expensive flooding, and flood repairs, and loss of crops through both flooding and droughts, it would seem to be common sense to spend a huge, sum now to build the infrastructure needed to store and distribute excess rain water, than repeatedly pay huge sums to counter the effects of flooding and possible droughts every year.
I remember someone in government suggesting that a huge North, South pipeline was built to bring water from the North where there always seems to be plenty / in some cases too much, to the South where droughts hit in the summer, which was met with a comment from someone in the North saying you`re not having oour water. Wonder if that person is still saying that now?
turbobloke said:
As per my original post, spending tens and hundreds of $billions on unreliable renewables is not going to reduce the tragedy of lost lives and flooded homes/businesses. Less than that amount of money spent on adequate flood defences (rather than stupidly thinking we can spend it to control nature) would have a massively beneficial impact on people's lives where homes and businesses are most at risk.
Here's what Terry Marsh actually said in 2007:"A series of major flood episodes in the early years of the 21st century has fuelled speculation that flood risk is increasing due to global warming. By their nature however, any cluster of extreme hydrological events cannot readily be linked to climate change. If they form part of a developing pattern or emerging trend, then a causative association becomes more plausible. Over the last 30-40 years, positive trends in a number of high river flow indicators (e.g. flood frequency, 30-day maxima) have been identified and increases in intense rainfall have been observed over a similar period. Generally, these studies have shown the most pronounced changes in the more maritime northern and western areas of the UK, and these have been related to changes in atmospheric circulation patterns which typically affect winter precipitation." - in other words at that time it was too early to say whether the extreme event was related to climate change.
Here's what his colleagues (and co-author in the above paper) say now:
https://www.ceh.ac.uk/sites/default/files/ceh_floo...
As for the Barredo paper, well it has a major flaw as the author recognised:
"It is worth noting that potential effects of human alterations in river basins have not been taken into account. Rather, this study assumed constant flood mitigation through time. In regions where relevant flood mitigation measures have been implemented during the period studied any changes in the frequency of extreme floods may have been offset by the measures adopted. Considering the effects of flood-protection measures, however, is a complex issue because accurate data on measures such as investment in flood protection is not available in a standardised format at continental level."
It's pretty clear that investment in flood mitigation has increased over the last few decades with more and higher defences being built which would tend to offset the effects of increases in flood flows.
Re the balance between renewables and mitigation - you may have a point. Renewables may offset additional impacts of climate change but my understanding is that the effects of existing levels of CO2 are yet to fully play out so continued work to mitigate is essential.
Lotus 50 said:
Re the balance between renewables and mitigation - you may have a point. Renewables may offset additional impacts of climate change but my understanding is that the effects of existing levels of CO2 are yet to fully play out so continued work to mitigate is essential.
The trouble with renewables is that unless you can get everyone else onboard all you get is the moral high ground, which is less useful than the actual high ground. Which isn't to say that we shouldn't try.Abbott said:
What is the current state of the water table and height of water in réservoirs. Not so long ago they were all at desperately low levels and no sign of recovering. Are they all full now?
Toward the end of last year we were looking at a hosepipe ban possibly this year but I'm not sure how it stands now. I work for a water company and the problem for us is long periods of dry weather reduce reservoir levels, even if large amounts of rainfall in a short period replenishes them it's not usually enough. We need consistent rainfall ideally but we're better prepared to mitigate water shortages than ever before.Pan Pan Pan said:
Watching and reading the various articles on the flooding that has occurred across the UK, and the references to climate change, where droughts are allegedly predicted for the UK in summer, the thought struck me that perhaps a suitable response to this, would be for the UK to build massive new reservoirs, into which flood waters could be diverted/pumped.
Water is expensive to move. It's heavy (vs gas) - which is partly why we don't have a national water grid.Also given some of the local rivers were seeing 350 tons / second I'm not sure how we would move that kind of volume?
vaud said:
Water is expensive to move. It's heavy (vs gas) - which is partly why we don't have a national water grid.
Also given some of the local rivers were seeing 350 tons / second I'm not sure how we would move that kind of volume?
Of very turbid water with high levels of contamination too.Also given some of the local rivers were seeing 350 tons / second I'm not sure how we would move that kind of volume?
Do we have droughts in this country anyhow? Maybe I didn't get to hear about them or forgot, but certainly we haven't had one up North since the 70s.
We have plenty of reservoirs and water in the North and they are all linked together already so water is pumped around wherever and whenever needed.
We have plenty of reservoirs and water in the North and they are all linked together already so water is pumped around wherever and whenever needed.
Pan Pan Pan said:
Indeed I was reminded of the scheme in Wales? I believe where water is pumped up to a newly built reservoir in the mountains, using off peak electricity for the pumps, which was then released to power a hydro elec plant during the times of high demand during the day. So yes, hydro electricity could also be a side benefit of reducing or stopping flooding in the winter, and supplying water in times of drought.
A posted earlier it cannot be cheap, but compared to repeatedly having to pay out millions or billions to mitigate the effects of repeated flooding, or drought conditions, would suggest that in the long term it would be money well spent.
I’ve been with the kids to the one in Llanberis, Dinorwig. http://www.electricmountain.co.uk/A posted earlier it cannot be cheap, but compared to repeatedly having to pay out millions or billions to mitigate the effects of repeated flooding, or drought conditions, would suggest that in the long term it would be money well spent.
Closed for refurb at the moment but it’s an amazing place and the kids thought it was like something from James Bond when you go underground on the tour bus and you then get to walk around. Recommended for anyone interested in this sort of thing.
Evoluzione said:
Do we have droughts in this country anyhow? Maybe I didn't get to hear about them or forgot, but certainly we haven't had one up North since the 70s.
We have plenty of reservoirs and water in the North and they are all linked together already so water is pumped around wherever and whenever needed.
Some are linked but not all.We have plenty of reservoirs and water in the North and they are all linked together already so water is pumped around wherever and whenever needed.
We had a massive water shortage in 1995, which is what lead to many new links. Bradford nearly ran out of water, which lead to emergency tankers bringing water in from Cumbria and water bowsers on some streets.
otolith said:
vaud said:
Water is expensive to move. It's heavy (vs gas) - which is partly why we don't have a national water grid.
Also given some of the local rivers were seeing 350 tons / second I'm not sure how we would move that kind of volume?
Of very turbid water with high levels of contamination too.Also given some of the local rivers were seeing 350 tons / second I'm not sure how we would move that kind of volume?
Also, if we are predicted to suffer increasing episodes of drought in the summers, will we then have to pay huge sums to pump up, and process sea water into potable water for times when there is not enough?
For some water schemes around the world, handling 350 tons of water per second is just chicken feed.
All water is contaminated, which is why we use reservoirs to store it, and water processing plants to clean it ready for human consumption.
For centuries the more enlightened cultures are those who store a commodity when there is an abundance of it, for use later when there is not enough.
It is just a question of whether we want to pay for water handling, (and damage caused) every time flooding, and droughts occur, or whether we take a (massive and expensive) one off step to store water, when there is too much of it, and in the process, help to reduce, if not eradicate flooding in the winters, and then have it available for use when there is not enough of it.?
It needs someone very clever to do the sums, and work out which approach is best in the long term.
This of course would just be a numbers game, since it would not take into account the suffering caused by those who suffer the effects of flooding, and droughts on their lives and their businesses on a continually repeating basis.
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