Flooding Not Increasing In North America And Europe, New Study Confirms

“The results of this study, for North America and Europe, provide a firmer foundation and support the conclusion of the IPCC that compelling evidence for increased flooding at a global scale is lacking.”

Screenshot-2017-08-30-11.28.08-768x900

Fig. 2. Monthly distribution of floods with ≥25 year return periods for 1204 study gauges from 1961 to 2010, by major Köppen-Geiger climate for North America on the left in green and Europe on the right in blue. Monthly values are percent of total number of floods with > 25 year return periods for each Köppen-Geiger climate.

G.A. Hodgkins et al., Climate-driven variability in the occurrence of major floods across North America and Europe, Journal of Hydrology, Volume 552, September 2017, Pages 704-717

Abstract

Concern over the potential impact of anthropogenic climate change on flooding has led to a proliferation of studies examining past flood trends. Many studies have analysed annual-maximum flow trends but few have quantified changes in major (25–100 year return period) floods, i.e. those that have the greatest societal impacts. Existing major-flood studies used a limited number of very large catchments affected to varying degrees by alterations such as reservoirs and urbanisation. In the current study, trends in major-flood occurrence from 1961 to 2010 and from 1931 to 2010 were assessed using a very large dataset (>1200 gauges) of diverse catchments from North America and Europe; only minimally altered catchments were used, to focus on climate-driven changes rather than changes due to catchment alterations. Trend testing of major floods was based on counting the number of exceedances of a given flood threshold within a group of gauges. Evidence for significant trends varied between groups of gauges that were defined by catchment size, location, climate, flood threshold and period of record, indicating that generalizations about flood trends across large domains or a diversity of catchment types are ungrounded. Overall, the number of significant trends in major-flood occurrence across North America and Europe was approximately the number expected due to chance alone. Changes over time in the occurrence of major floods were dominated by multidecadal variability rather than by long-term trends. There were more than three times as many significant relationships between major-flood occurrence and the Atlantic Multidecadal Oscillation than significant long-term trends. […]

5. Conclusions

Reference hydrologic networks isolate catchments where climate has been the principal driver of streamflow change by minimizing other drivers, such as regulation, diversions and urbanisation. The relationship between floods and climate change is more difficult to discern where catchments have been altered, making attribution to any single driver uncertain.

Trends over time in the occurrence of major floods (exceeding 25, 50, and 100 year return periods) in North America and Europe were evaluated for 1961–2010 and 1931–2010. All gauges drain catchments that are considered by local and national experts to be minimally affected by catchment alterations. Trend testing of major floods required the grouping of gauges. The 1204 gauges that met study criteria for 1961–2010 and the 322 gauges for 1931–2010 were grouped by continent, Köppen-Geiger climate and catchment size. The number of significant trends for 246 groups of gauges was approximately the same as would be expected by chance alone.

There were more than three times as many groups of gauges with significant relationships between the number of annual major floods and annual values of the Atlantic Multidecadal Oscillation than expected due to chance. Catchment size was important to the results; there were significant negative relations between floods and the AMO at large (>1000 km2) North American catchments and significant positive relations at medium (100–1000 km2) European catchments. The opposite relations between European and North American major flood occurrence and the AMO are consistent with previous work on general wetness and dryness related to the AMO. There were no significant relationships, for any group of catchments, between major flood occurrence and the Pacific Decadal Oscillation.

The results of this study, for North America and Europe, provide a firmer foundation and support the conclusion of the IPCC (Hartmann et al., 2013) that compelling evidence for increased flooding at a global scale is lacking. Generalizations about climate-driven changes in floods across large domains or diverse catchment types that are based upon small samples of catchments or short periods of record are ungrounded. Networks of streamflow data from minimally altered catchments will provide an essential foundation for future efforts to understand the complex temporal and spatial dynamics of major floods.

See the full study here.

HT/The GWPF

0 0 votes
Article Rating
72 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
Rob
August 31, 2017 2:12 pm

“The results of this study, for North America and Europe, provide a firmer foundation and support the conclusion of the IPCC that compelling evidence for increased flooding at a global scale is lacking.”
What fabulous wording for “Nah, nothing to do with CO2!”

john harmsworth
Reply to  Rob
August 31, 2017 3:23 pm

Complete weasel words! “Evidence is lacking”, means they are still looking for evidence. The truth is that evidence for any increase in flooding doesn’t exist!
Soon we will start to see “adjustments” to the records of past floods along with what we see already- no recognition of the effect of land use and paving in aggravating flood conditions. Rainfall records for virtually any location on Earth show essentially random annual amounts within specific wide bounds for the specific location.
Sea level rise shows no acceleration in about 200 years. Even the recovery from the LIA has not accelerated it.

Caligula Jones
Reply to  john harmsworth
September 1, 2017 9:35 am

“The truth is that evidence for any increase in flooding doesn’t exist!”
As Cardinal Richelieu said “give me six words from an innocent man, and I’ll find enough to hang him”.
Wait for the inevitable torturing of data, all under the phony auspices of “improving” it, i.e., “getting the result we actually wanted”.
BTW, the Gutenberg Press is a trove of history, if you look. For example:
http://www.gutenberg.org/files/44568/44568-h/44568-h.htm
In 1706, a great part of the city was laid under water by two violent floods, both of which happened in the month of November.
On October 27th, 1762, there was a sudden flood in the city, which laid near 300 houses and 8 parish churches under water. It rose 12 feet perpendicular in 24 hours, being 15 inches higher than St. Faith’s flood in 1696.
On November 19th, 1770, there was a great flood in Norwich, four inches higher than that of 1762. The sufferers were relieved, by a subscription, with money, coals, and bread. On December 19th, of the same year, there was a violent storm of wind and rain, such as had not been remembered since 1741. Happisburgh, Postwick, and Strumpshaw windmills were blown down, and much damage was done in the city and county; many ships with their crews were lost on the Norfolk coast. In the same year the following turnpike roads were made and opened, from St. Stephen’s Gates to Trowse, from St. Stephen’s Gates to Watton, from St. Benedict’s Gates to Swaffham, from Bishop Bridge to Caister near Yarmouth, and from Norwich to Dereham, Swaffham, and Mattishall.
or this one:
http://www.gutenberg.org/files/39920/39920-h/39920-h.htm
Etc.

ph
Reply to  Rob
August 31, 2017 4:41 pm

An honest statement from the ipcc would be “there is compelling evidence that flooding is not increasing on a global scale.” But what can you expect from a bunch of mealy-mounted politicians. No capitals because the ipcc deserves no respect.

Mary Brown
Reply to  Rob
September 12, 2017 6:13 pm

Not to mention that the burden of proof lies with those making the Chicken Little claims. It is not up to skeptics to provide proof that it isn’t happening.

Latitude
August 31, 2017 2:17 pm

I don’t know of anything that’s increased…
…a lot of things have decreased

August 31, 2017 2:17 pm

A timely paper, it I guess you will never hear of it on the BBC or in the Guardian in the UK

August 31, 2017 2:19 pm

Kudos to the Journal of Hydrology for publishing a paper showing no trend.

Nick Stokes
August 31, 2017 2:21 pm

“Flooding Not Increasing In North America And Europe, New Study Confirms”
It doesn’t confirm that. It says that compelling evidence is lacking. That doesn’t confirm anything. In fact, they say
“The overall occurrence of major floods in Europe from 1961 to 2010 increased, but not significantly, based on floods at 559 gauges (Fig. 3). The overall occurrence of major floods at 645 gauges in North America changed very little over this period. For the period 1931–2010, the overall occurrence of major floods in Europe (128 gauges) changed very little whilst floods increased overall in North America (194 gauges) but not significantly except for 25 year floods (Fig. 4).”
There is some tendency to increase. They can’t be sure that it wasn’t due to chance. That isn’t the same as saying that it didn’t happen.

richard
Reply to  Nick Stokes
August 31, 2017 2:30 pm

Even if there was an increase it was probably due to building development –
Effects of Urban Development on Floods
“The effect of urban development in the last half of the 20th century on small floods is evident in Salt Creek, Illinois. With the exception of an unusually large flood in 1987, large floods have increased by about 100 percent (from about 1,000 cubic feet per second to about 2,000 ft3/s) while small floods have increased by about 200 percent (from about 400 ft3/s to 1,200 ft3/s). Nonetheless, even a small increase in the peak discharge of a large flood can increase flood damages.
The frequency of moderate flooding can increase substantially after development. The annual frequency that daily discharge exceeded 1,000 ft3/s on the Northeast Branch of the Anacostia River in Maryland increased from once or twice per year in the 1940s and 1950s to as much as six times per year in the 1990s”
https://pubs.usgs.gov/fs/fs07603/

Nick Stokes
Reply to  richard
August 31, 2017 2:52 pm

“Even if there was an increase it was probably due to building development”
These people are hydrologists and are well aware of that issue. They aren’t measuring urban flooding.
“Detecting changes in floods attributable to changes in climate requires some rigour (Merz et al., 2012). The importance of isolating climate influences on flood trends from other influences is becoming widely recognized (Stahl et al., 2010; Wilson et al., 2010; Murphy et al., 2013; Mediero et al., 2014). In many countries, reference hydrologic networks have been designed and developed to provide good quality data and metadata from catchments without confounding land use changes, minimal hydrologic alterations such as flow regulation, and suitable long-term records (Whitfield et al., 2012; Burn et al., 2012). Many countries have developed reference hydrologic networks (Brimley et al., 1999; Bradford and Marsh, 2003; Marsh, 2010; Lins, 2012; Murphy et al., 2013; Fleig et al., 2013), whilst in others expert opinion is required to isolate this type of site. Care needs to be taken when including catchments from non-reference networks to avoid non-climatic influences. Burn and Whitfield (2016) demonstrated that differences in flood trends exist between reference sites and other sites in Canada that have unregulated streamflow but were not designated as reference sites.
The 1204 sites considered in this study were either designated as hydrologic reference sites (970 sites) [North America: Canada, United States; Europe: France, Ireland, Norway, United Kingdom] or considered to be equivalent (234 RHN-like sites) based upon detailed review by national and local experts (Denmark, Finland, Germany, Iceland, Spain, Sweden and Switzerland). All catchments had <10% current urban area (qualitative measure in some countries), no substantial flow alteration or known substantial land cover change, good quality peak-flow data and <10 years missing data."

Michael Jankowski
Reply to  Nick Stokes
August 31, 2017 2:56 pm

Pathetic.

john harmsworth
Reply to  Nick Stokes
August 31, 2017 3:28 pm

What is the effect on <10% urban area if that is double what it was in a previous period of categorization? It is not insignificant as a percentage of the flooding change. If you want to nitpick the numbers, let's do it right.

Nick Stokes
Reply to  john harmsworth
August 31, 2017 3:44 pm

“It is not insignificant as a percentage of the flooding change. If you want to nitpick the numbers”
This is how these threads get so muddled. The heading says “study confirms no increase in flooding”. All applaud. I quote what they actually say. Then I’m nit-picking, presumably to cover up the alleged flaw in the study (urban run-off).
Are we still applauding?

Latitude
Reply to  john harmsworth
August 31, 2017 3:53 pm

“support the conclusion of the IPCC ……… that compelling evidence for increased flooding at a global scale is lacking”

Nick Stokes
Reply to  Nick Stokes
August 31, 2017 3:49 pm

I think even a lawyer would understand the difference between not being proved guilty and being proved innocent. There is a basic difference between “we can’t be sure yet that X is happening” and “we confirm that X is not happening”. Often missed here.

SkepticGoneWild
Reply to  Nick Stokes
August 31, 2017 3:57 pm

Nick,
I’ll read your post whenever I have insomnia.

Nick Stokes
Reply to  SkepticGoneWild
August 31, 2017 5:05 pm

If that fails, try reading the rest of the paper.

Latitude
Reply to  Nick Stokes
August 31, 2017 3:58 pm

When there’s no compelling evidence that a crime was committed in the first place…

richard
Reply to  Nick Stokes
September 1, 2017 1:42 pm

…and there is no trend but you can be sure that in the areas with increased flooding due to urban development alarmists now pin this on supposed man-made climate change.
That’s the problem- how do you stop alarmism of this kind.

Resourceguy
August 31, 2017 2:25 pm

The other conclusion is that Michael Mann is not a hydrologist in addition to all the other “Nots” like tree ring specialist.

john harmsworth
Reply to  Resourceguy
August 31, 2017 3:30 pm

He’s too smart for, like, data and stuff.

Ken In Kelowna
August 31, 2017 2:32 pm

Of course with each annual hurricane season the storms are assigned an alphabetic letter to track their sequence in order. The letter “H” signifies number eight of this storm season. It would have been ironic if, instead of naming the storm Harvey, it was named Hillary, because that bitch blows!

Jer0me
Reply to  Ken In Kelowna
August 31, 2017 3:05 pm

because that bitch blows!

Or possibly she does not, which is why Bill got on so well with Monica who does.

Reply to  Ken In Kelowna
August 31, 2017 4:44 pm

You guys are seriously jumping to conclusions (are you with me Nick?)
There is a basic difference between “we can’t be sure yet that X is happening (poorly)” and “we confirm that X is not happening”.
There is no evidence that Hillary does not [pruned] or [pruned] … it may well be that she is just very very bad at it.
This is how these threads get so muddled.

August 31, 2017 3:19 pm

Water vapor in the atmosphere is increasing about 1.5% per decade; has increased about 8% since 1960, Hard to believe that hasn’t caused increased rainfall.
What about the other 96% of the planet?

john harmsworth
Reply to  Dan Pangburn
August 31, 2017 3:45 pm

That would also be an important cause of higher nighttime temperatures, which I believe is the predominant feature of measured global warming. The AGW crowd talks constantly about unlivable high temperatures in the future ( always might, probably, could be) but the reality is there is No sign of these higher highs. Only higher lows, which is almost completely beneficial.
The bogeyman always turns out to that nice neighbor lady who bakes and does volunteer work, not some psycho killer! But the AGW crowd is so invested in their scare story that they can’t bear to look at the facts. Time will show them to be evil and misguided idiots, pursuing an anti-human agenda.

TA
Reply to  john harmsworth
August 31, 2017 5:31 pm

“That [higher levels of water vapor] would also be an important cause of higher nighttime temperatures, which I believe is the predominant feature of measured global warming.”
I agree. Some people want to claim CO2 is causing these increases in nighttime temperatures, but water vapor looks like a much better candidate to me.
I wonder how much the increased vegetation around the world from increased CO2 is adding to the increase in water vapor?

Germinio
Reply to  Dan Pangburn
August 31, 2017 6:12 pm

With regards the other 96% of the planet it is worth remember that while most of the media attention is focused on a small area of North America inhabited mainly by descendants of white Europeans on the other side of the globe major flooding has killed over 1200 people.

Mark
Reply to  Germinio
August 31, 2017 8:42 pm

Good point

David A
Reply to  Dan Pangburn
August 31, 2017 9:27 pm

Dan, do you have a link to this global increase in WV?

Reply to  David A
September 1, 2017 11:44 am

WV thru July 2017 Numerical data: http://data.remss.com/vapor/monthly_1deg/tpw_v07r01_198801_201707.time_series.txt . Last two digits are the latest month on line.
Graphed in Fig 3 at http://globalclimatedrivers2.blogspot.com

Reply to  David A
September 1, 2017 12:00 pm

Global increase in water use appears similar to WV increase with uptrend slope increase starting in about 1950: http://www.fao.org/nr/water/aquastat/water_use/index.stm

August 31, 2017 3:26 pm

Good post. And timely. Thanks.
My 2 cents on flooding.
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2929159

August 31, 2017 3:39 pm

I researched this separately when dissecting chapter 1 of the US National Climate Report 2014 for essay Credibility Conundrums. Came to the same conclusion. Where there is a documented local/regional increase, 100% was attributable to land use change, especially building in flood plains. Harvey and Houston have just given the world a memorable example. I believe Paul Homewood has documented similar results for the UK.
As for Nick Stokes comment the equivalent of ‘Absence of evidence is not evidence of absence’, just shows how far from the scientific method things have strayed. The null hypothesis is no change. The study could not falsify the null hypothesis, so it stands: no change despite CO2 now over 400ppm.

Nick Stokes
Reply to  ristvan
August 31, 2017 3:59 pm

“The null hypothesis is no change. The study could not falsify the null hypothesis, so it stands”
The null hypothesis is hypothetical. But a failure to falsify does not confirm it. It is just a failure. Often in fact, as here, the evidence is contrary to the hypothesis. It’s just not contrary enough for “certainty”.

Tsk Tsk
Reply to  Nick Stokes
August 31, 2017 4:36 pm

So now we can add discounting the null hypothesis to subsidies don’t impact markets. Clearly Nick is both an economic and statistics genius. How long have we been allied/at war with Eurasia again?

Nick Stokes
Reply to  Nick Stokes
August 31, 2017 5:02 pm

ctm,
“some of the flips will be contrary to the null hypothesis “
No, the hypothesis is that heads and tails are equally likely. A few tails aren’t contrary to that. But if you get 60 tails, the test probably says reject (the 50% hypothesis). If you get 59 tails, it might say fail to reject. That doesn’t mean 59 confirms the coin is fair. It’s consistent with anything from 50% to 68%.

DCA
Reply to  Nick Stokes
September 1, 2017 5:33 am

Nick seems to Trenberth in that the null hypothesis is that AGW causes flooding and other extreme weather.

DCA
Reply to  Nick Stokes
September 1, 2017 5:38 am

Nick seems to agree with Trenberth…..

Latitude
Reply to  ristvan
August 31, 2017 4:00 pm

Nick is already calling lawyers…when there’s no evidence a crime was even committed

David A
Reply to  Latitude
August 31, 2017 9:39 pm

Indeed, a small insignificant change is meaningless, perhaps a simple artifact of the extreme drought of the dust bowl.

john harmsworth
August 31, 2017 3:51 pm

Always disappointing how Nick resorts to nitpicking when he can’t find fault with the fundamentals. Integrity would suggest admitting to the validity of the argument. Since almost every aspect of AGW investigation results in the same, “nothing to see here”, I suppose that would just mean it’s time to put away the crayons and go home.

August 31, 2017 3:55 pm

Correction? Note the link provided in, “G.A. Hodgkins et al., Climate-driven variability in the occurrence of major floods across North America and Europe, Journal of Hydrology, Volume 552, September 2017, Pages 704-717′ is a link to the ‘Times of Israel.’
The link at the top of the post works.
Thanks

commieBob
August 31, 2017 4:07 pm

I can tell you why it doesn’t flood where I live. You’re not allowed to build where there is a chance of getting flooded. Period. Works like a charm.

Reply to  commieBob
August 31, 2017 4:53 pm

And I can tell you why there are no earthquakes where I live. No one is allowed to build where there is chance of the structure being impacted by an earthquake. Haven’t had an earthquake yet 🙂

August 31, 2017 4:46 pm

I think you’re wrong here, Nick. This isn’t the hoary truism “absence of evidence is not evidence of absence,” this IS evidence of absence. Let’s break down the conclusion:

The number of significant trends for 246 groups of gauges was approximately the same as would be expected by chance alone.

I don’t like this phrasing. WAS the trend for those 246 groups the same as expected by chance alone, or was it NOT? This seems a bit weaselly for a scientific study. If those trends were inside the 2 sigma range then they WERE the same as expected by chance alone, because that IS the definition of chance, or statistically insignificant, if you prefer.

There were more than three times as many groups of gauges with significant relationships between the number of annual major floods and annual values of the Atlantic Multidecadal Oscillation than expected due to chance. Catchment size was important to the results; there were significant negative relations between floods and the AMO at large (>1000 km2) North American catchments and significant positive relations at medium (100–1000 km2) European catchments. The opposite relations between European and North American major flood occurrence and the AMO are consistent with previous work on general wetness and dryness related to the AMO.

I presume the “three times as many” refers to the 246 groups that were within the realm of chance, and their trends were due to the AMO, and thus NOT to any anthropogenic warming. Plus they were of opposite signs on opposite sides of the Atlantic, more evidence of non-warming influence.

There were no significant relationships, for any group of catchments, between major flood occurrence and the Pacific Decadal Oscillation.

As Monty Python might have said, the PDO was right out for influencing North American or European floods.

The results of this study, for North America and Europe, provide a firmer foundation and support the conclusion of the IPCC (Hartmann et al., 2013) that compelling evidence for increased flooding at a global scale is lacking. Generalizations about climate-driven changes in floods across large domains or diverse catchment types that are based upon small samples of catchments or short periods of record are ungrounded.

(Emphasis mine.)
“Support the conclusion of the IPCC (Hartmann et al., 2013) that compelling evidence for increased flooding at a global scale is lacking” is pretty non-weaselly. They’ve looked at the evidence they have, and it is NOT evidence for increased flooding at a global scale. However, it IS evidence that the AMO has a positive effect on European flooding and a negative effect on the North American side.
Not much is ever CONFIRMED in science; at best, one can only reach the condition exemplified by Stephen Jay Gould when he said “In science, ‘fact’ can only mean ‘confirmed to such a degree that it would be perverse to withhold provisional assent.’ I suppose that apples might start to rise tomorrow, but the possibility does not merit equal time in physics classrooms.”
For now, the available evidence says “no increased flooding due to warming.” New evidence gathered later may show a change. But until it does, we can say right now that the evidence definitely supports the null hypothesis and not the AGW hypothesis.

Nick Stokes
Reply to  James Schrumpf
August 31, 2017 5:41 pm

James,
“and their trends were due to the AMO, and thus NOT to any anthropogenic warming. Plus they were of opposite signs on opposite sides of the Atlantic, more evidence of non-warming influence.”
No, if anything, it’s evidence of non-AMO influence. In fact, all that you have quoted is where they look for correlation with AMO or PDO (and don’t find much). That doesn’t prove anything about warming.
What they do say, in the sections I’ve quoted, is that there is observed increase in flooding over time. It’s not consistent, and because the events are rare, there is a strong influence of chance. There is also the difficulty of separating out drainage improvements and land use effects. All of this says that this is a difficult test to get conclusive results. It doesn’t say that the tests are conclusive about no increase in flooding. The IPCC conclusion that they paraphrase is the same. Compelling evidence is lacking. That is mainly because of the effects of chance and confounding factors. That provides fuzz, not confirmation (of anything). The AR5 (Chap 2, Exec Summary) also said:
“is likely that since about 1950 the number of heavy precipitation events over land has increased in more regions than it has decreased. Confidence is highest for North America and Europe where there have been likely increases in either the frequency or intensity of heavy precipitation with some seasonal and/or regional variation. It is very likely that there have been trends towards heavier precipitation events in central North America. {2.6.2.1}”

James Schrumpf
Reply to  Nick Stokes
August 31, 2017 8:36 pm

Nick:
They said “The opposite relations between European and North American major flood occurrence and the AMO are consistent with previous work on general wetness and dryness related to the AMO.”
Which part of that says to you “it’s evidence of non-AMO influence”? I read that sentence and see them saying those opposite relations are related to the AMO. Is it really possible to read that sentence and honesty parse it as them saying it has nothing to do with the AMO?
And what’s with all the “it is likely” phrases from the AR5? That’s not scientific, that’s political. The scientific article clearly stated that “Changes over time in the occurrence of major floods were dominated by multidecadal variability rather than by long-term trends.”
They referenced the difficulty of getting good data as well: “…only minimally altered catchments were used… Reference hydrologic networks isolate catchments where climate has been the principal driver of streamflow change by minimizing other drivers, such as regulation, diversions and urbanisation. The relationship between floods and climate change is more difficult to discern where catchments have been altered, making attribution to any single driver uncertain.”
In short, they did everything they could to use only catchments with minimal alterations, the better to see the climate signal — if any — separate from land use, dredging, etc, or anything else that could affect the measurements.
I’m surprised you’re trying so hard to not see the article as a refutation of the AGW-flood-increase hypothesis. This isn’t like looking for Bigfoot, finding no evidence, and claiming that you didn’t disprove his existence. This is getting tons of evidence that supposedly would prove Bigfoot existed, and having it prove exactly the opposite

Nick Stokes
Reply to  Nick Stokes
August 31, 2017 9:00 pm

James,
” This is getting tons of evidence that supposedly would prove Bigfoot existed, and having it prove exactly the opposite”
It didn’t prove the opposite. I quoted their results above. They found quite a lot of increased flooding. They just couldn’t rule out, statistically, that it might have occurred by chance.

Reply to  Nick Stokes
September 1, 2017 3:33 am

Nick: Let’s cut this to the quick: “evidence for increased flooding at a global scale is lacking.”
Didn’t say flooding was decreasing. Didn’t say there was not a lot of flooding. Said there’s no evidence of increased flooding at the global scale. The evidence points at NO increased flooding.
This is not “they found no evidence.” This is “there’s lots of evidence, and it points at no increased flooding.”

Nick Stokes
Reply to  Nick Stokes
September 1, 2017 12:55 pm

“This is not “they found no evidence.” This is “there’s lots of evidence, and it points at no increased flooding.””
They didn’t say that at all. I’ll quote again what they did say:
“The overall occurrence of major floods in Europe from 1961 to 2010 increased, but not significantly, based on floods at 559 gauges (Fig. 3). The overall occurrence of major floods at 645 gauges in North America changed very little over this period. For the period 1931–2010, the overall occurrence of major floods in Europe (128 gauges) changed very little whilst floods increased overall in North America (194 gauges) but not significantly except for 25 year floods (Fig. 4).”
Increased but not significantly. That isn’t no increase. It’s an increase which is observed, but because of the difficulties in measurement, is not statistically significant – ie you can’t be sure that it couldn’t have arisen by chance.

August 31, 2017 4:55 pm

The null hypothesis is hypothetical. But a failure to falsify does not confirm it. It is just a failure. Often in fact, as here, the evidence is contrary to the hypothesis. It’s just not contrary enough for “certainty”.

The difference here is that the IPCC concluded that there is NO relationship between warming and increased flooding. The evidence supports that conclusion. It’s not that the evidence is inconclusive, it definitely supports one position — the position that there is no relationship.
How do you not see such a simple relationship?

Philip Schaeffer
Reply to  James Schrumpf
August 31, 2017 6:16 pm

I can understand Nick’s frustration here. Concluding that there is no compelling evidence of a relationship at this time is not the same as concluding that there is no relationship.
There may not be compelling evidence that you shot someone, but that doesn’t prove that you didn’t do it. At that moment you wouldn’t be convicted, but as more evidence is compiled, that may change.

Reply to  Philip Schaeffer
September 2, 2017 6:00 am

You, like Nick, are missing the point. The evidence is showing that NO ONE HAS BEEN SHOT. We’re not at the point where we’re assigning blame for an event — the event has not occurred.
The report concludes with “evidence for increased flooding at a global scale is lacking.” It doesn’t say “no evidence that increased flooding at a global scale is caused by global warming.” It says there IS NO increased flooding. There’s nothing happening to blame or absolve global warming of.
THIS IS A DEAD PARROT! I’m running out of ways to say that there is no there there.

David A
Reply to  James Schrumpf
August 31, 2017 9:44 pm

Nick says “They found quite a lot of increased flooding. ”
WOW! Really? Are you certain?

Pamela Gray
August 31, 2017 5:46 pm

The reason why measures of significance have been developed is so humans are not driven down the snake oil primrose path. That is not to say snake oil might work. But it is better to avoid such oil till there is a true valid and reliable use for snake oil. Nick, are you saying we should jump over this well established warning barrier regarding CO2 anyway? How does that comport with the reason significance became the necessary measure for action or no action? If you say “maybe” then we could also say bouncing balls back and forth has all kinds of health benefits. It seems to me this weaseling around the significance issue isn’t post modern science, it is Neanderthal science!!!!

Nick Stokes
Reply to  Pamela Gray
August 31, 2017 6:44 pm

“If you say “maybe” then we could also say bouncing balls back and forth”
You say it if it’s true. Then you work out what to do about it, which is a separate issue from finding out what is true, and depends on which way caution leads you. But to see how you need to keep an open mind on “maybe”, look at ctm’s coin example, but with smaller numbers. You’re tossing a coin to see if it is fair. You get 5 heads and test statistically. There is a 1/16 chance of getting 5 of a kind, which doesn’t quite break 95%. So do you say
1. can’t rule out fair, or
2. confirmed fair?
Suppose you toss 5 more times and get 5 more heads. Having chosen 1 you might say, that’s now very improbable that it’s fair (in fact, 1/512). While a fan of 2 would say – see, we’ve confirmed twice that it’s fair!

nankerphelge
August 31, 2017 6:27 pm

Just saw Bernie Sanders on CNN stating categorically that (my paraphrase) “…..these 100 year storms seem to occur every few years….” and most “…..scientists seem to relate this to climate change…..”.
This battle is so far from over that I doubt it will be won before the next cooling.

SAMURAI
August 31, 2017 10:07 pm

Over the past 50~100 years (depending on weather event), even IPCC’s AR5 Report admits there is no evidence that serve weather events are increasing in either frequency or intensity for the following: hurricanes, cyclones, typhoons, floods, droughts, tornadoes, thunderstorms, subtropical storms, tropical storms and hail:
https://wattsupwiththat.com/2013/10/03/pielke-jr-agrees-extreme-weather-to-climate-connection-is-a-dead-issue/
For the MSM to state otherwise is just Leftist propaganda.
Leftist MSM and political hacks simply repeat lies they know are false to keep the CAGW narrative alive and keep the CAGW money train chugging along.
A 2008 UN Climate Change Report estimates the cost to global taxpayers for implementing CAGW government policies at $76 TRILLION over 40 years, which is 76 TRILLION reasons why Leftists want to keep the CAGW agenda alive.
Just follow the money and all is made clear.

Boels
September 1, 2017 12:31 am

No data used from The Netherlands (aka Holland)?
Too well organized there?

Griff
Reply to  Boels
September 1, 2017 1:59 am

They are…
They have put a lot of effort into flood resilience
Here’s a report on Rotterdam…
http://blogs.nottingham.ac.uk/blue-greencities/2016/04/11/the-journey-towards-a-flood-proof-rotterdam/
I hope US cities will be putting similar programmes into place…

Boels
Reply to  Griff
September 1, 2017 3:02 am

Another one:
https://www.nytimes.com/interactive/2017/06/15/world/europe/climate-change-rotterdam.html?action=click&contentCollection=Climate&module=RelatedCoverage&region=EndOfArticle&pgtype=article
But “sold” by NYT as measures to counter climate change. In fact a result of the long running evolving “Delta Plan” following the 1953 disaster.

Griff
September 1, 2017 1:57 am

It has increased in the UK since 2000
There has been climate change which affects the UK – we now frequently get sets of depressions off the Atlantic bringing slow moving intense rain storms.
We have seen new record rainfall areas and places experiencing a string of 1 in 100 year floods…

Reply to  Griff
September 2, 2017 6:06 am

Not sure that a cold, rainy island getting more cold and rainy weather is actually “climate change.”
Sounds more like “climate reinforcement.”

catweazle666
Reply to  Griff
September 2, 2017 12:37 pm

“It has increased in the UK since 2000”
No it hasn’t.
“There has been climate change which affects the UK”
More blatant lies.
*snip*
(name calling/disrespect is not tolerated here, by anyone, to anyone. Treat each other with respect no matter how strongly you disagree with them. If you strongly disagree with their post, show their position to be wrong factually, if you can, but respect the person you disagree with. 1st warning.)

catweazle666
Reply to  Griff
September 2, 2017 12:40 pm

More lies…

Charlie
September 1, 2017 3:26 am

There are various factors which impact on flooding
1. Rainfall intensity
2. Total rainfall.
3. Saturation of ground.
4. Change in run off characteristics which can be urbanisation, change in land use or even change in framing methods. Depending upon method used,run off can be proportionate to the run off characteristics of the soil/vegetation to the power 2.17. Relatively small changes say from pasture to cereal could increase run off from fields by 40-60%.
5. Human records for rainfall in the UK and NE USA may go back 140 years but in Texas impacted by storms there needs to 100s of years of records to make a reliable assessment of long term trends. In some parts of the World there is heavy rainfall every year but in other parts it may be only every decade or 100 years. Once the frequency of heavy rain is greater than decades and then the only way to assess it is via the geological/soil record.

September 1, 2017 5:13 am

the link to the paper is a ToI link, w t eph

JEyon
September 1, 2017 8:13 am

i hate finding myself on the same side as Nick Stokes (about as much as he hates seeing me there) – but probably my most frequent objection to WUWT articles has been how the articles titles are contradicted – in subtle but significant ways – by close reading of the article or the source material – in this case – “confirmed” was the wrong word – and is isn’t necessary to defend it!
considering the claims “1) Compelling evidence is lacking” and “2) Confirms” – and introducing “3) Disproves” – in ongoing research – the first statement promises the second and challenges the third

barry
September 3, 2017 7:03 pm

See the full study here
I only got the abstract at that link. Does anyone have a link to the full report? Couldn’t find it.
I’m curious to see if coastal flooding trends are examined: to see if higher sea levels -> shallower run-off gradient has had some influence.