Why the “never seen before” Fargo flooding is just what you’d expect from global warming, as Obama warns

Posted on

"Why the “never seen before” Fargo flooding is just what you’d expect from global warming, as Obama warns"

[Note: I have tried to link to the relevant literature on extreme precipitation trends. If I've missed any, let me know.]

I actually think the science around climate change is real. It is potentially devastating,” Obama told reporters Monday. “If you look at the flooding that’s going on right now in North Dakota and you say to yourself, ‘If you see an increase of two degrees, what does that do, in terms of the situation there?’ That indicates the degree to which we have to take this seriously.

fargo.gif

Besides Obama, the British and the Chinese understand global warming has driven their record flooding. The United States media? Not so much.

Certainly North Dakota is experience record-breaking flooding:

Flooding in the Red River Valley is reaching levels never seen before.

So wrote Noreen Schwein, water program director at National Weather Service central region headquarters. Fargo’s mayor calls the flooding “uncharted territory.”

But you’ll have to look very hard to find a single story in the mainstream media that even mentions climate change (other than the few quoting our President) — even though the record “once-in-a-hundred-year flooding” the Midwest now seems to be getting every few years or so is precisely what scientists have been expecting from the warming [see "Global warming causes deluges and flooding, just like the Midwest is seeing (again)."]

In fact, in 2004, the Journal of Hydrometeorology published an analysis by NOAA’s National Climatic Data Center that found “Over the contiguous United States, precipitation, temperature, streamflow, and heavy and very heavy precipitation have increased during the twentieth century.” [And yes, this applies to snow, depending on the location, see below.]

They found (here) that over the course of the 20th century, the “Cold season (October through April),” saw a 16% increase in “heavy” precipitation events (roughly greater than 2 inches [when it comes as rain] in one day), and a 25% increase in “very heavy” precipitation events (roughly greater than 4 inches in one day)– and a 36% rise in “extreme” precipitation events (those in the 99.9% percentile — 1 in 1000 events). This rise in extreme precipitation is precisely what is predicted by global warming models in the scientific literature.

In fact, the last few decades have seen rising extreme precipitation over the United States in the historical record, according to NCDC’s Climate Extremes Index (CEI):

An increasing trend in the area experiencing much above-normal proportion of heavy daily precipitation is observed from about 1950 to the present.

Here is a plot of the percentage of this country (times two) with much greater than normal proportion of precipitation derived from extreme 1-day precipitation events (where extreme equals the highest tenth percentile of deluges, click to enlarge):

cei-4-08.gif

Didn’t know that our government kept a Climate Extremes Index? Why would you? The media never writes about it.

The U.S. Climate Extremes Index was explicitly created to take a complicated subject (“multivariate and multidimensional climate changes in the United States“) and make it more easily understood by American citizens and policy makers. As far back as 1995, analysis by the National Climatic Data Center showed that over the course of the 20th century, the United States had suffered a statistically significant increase in a variety of extreme weather events, the very ones you would expect from global warming, such as more — and more intense — precipitation. That analysis concluded the chances were only “5 to 10 percent” this increase was due to factors other than global warming, such as “natural climate variability.” And since 1995, the climate has gotten much more extreme.

Even the Bush Administration in its must-read U.S. Climate Change Science Program report, Weather and Climate Extremes in a Changing Climate, acknowledged:

Many extremes and their associated impacts are now changing…. Heavy downpours have become more frequent and intense….

It is well established through formal attribution studies that the global warming of the past 50 years is due primarily to human-induced increases in heat-trapping gases.… The increase in heavy precipitation events is associated with an increase in water vapor, and the latter has been attributed to human-induced warming.

One more key point: Because this flooding involves snow — and because some global warming doubters seem to think that every snowstorm is proof global warming isn’t occuring — let me just make the obvious point. With the increase in “cold season” precipitation and extreme precipitation, you would expect that it comes down as snow where it is cold, but less so where it is warm.

A 2005 study, coauthored by NCDC, “Temporal and Spatial Characteristics of Snowstorms in the Contiguous United States,” found:

The temporal distribution of snowstorms exhibited wide fluctuations during 1901–2000, with downward 100-yr trends in the lower Midwest, South, and West Coast. Upward trends occurred in the upper Midwest, East, and Northeast, and the national trend for 1901–2000 was upward, corresponding to trends in strong cyclonic activity.

We have seen more snow overall and especially in the places where it is the coldest. Obviously, global warming has warmed “threshold” or more southern locations enough to turn many snowstorms into rain or ice storms.

Finally, if you are a journalist wondering what is a reasonable way to talk about this, one of the best recent examples comes from a New York Times story on Australia made possible by our friend Andrew Revkin:

The firestorms and heat in the south revived discussions in Australia of whether human-caused global warming was contributing to the continent’s climate woes of late — including recent prolonged drought in some places and severe flooding last week in Queensland, in the northeast.

Climate scientists say that no single rare event like the deadly heat wave or fires can be attributed to global warming, but the chances of experiencing such conditions are rising along with the temperature. In 2007, Australia’s national science agency published a 147-page report on projected climate changes, concluding, among other things, that “high-fire-danger weather is likely to increase in the southeast.”

The flooding in the northeast and the combustible conditions in the south were consistent with what is forecast as a result of recent shifts in climate patterns linked to rising concentrations of greenhouse gases, said Kevin Trenberth, a scientist at the United States National Center for Atmospheric Research.

That’s how it is done.

And no, I’m not say that the media should link every extreme weather event the way Revkin did. But when we have “worst on record” type events, or 100-year floods — and especially ones that last more than a day and hit a broad area — then I think the reporter has an obligation to include the issue.

Related Posts:

« »

52 Responses to Why the “never seen before” Fargo flooding is just what you’d expect from global warming, as Obama warns

  1. MarkO says:

    100 year floods are now common place in America’s heartland. Mother Earth proving that this will affect ALL of us.

  2. DB says:

    The U.S. Climate Change Science Program report, Weather and Climate Extremes in a Changing Climate, wrote this about streamflows (p. 53):

    “Lins and Slack (1999, 2005) reported no significant changes in high flow above the 90th percentile. On the other hand, Groisman et al. (2001) showed that for the same gauges, period, and territory, there were statistically significant regional average increases in the uppermost fractions of total streamflow. However, these trends became statistically insignificant after Groisman et al. (2004) updated the analysis to include the years 2000 through 2003, all of which happened to be dry years over most of the eastern United States.”

  3. paulm says:

    Climate Catastrophe by a 1000 cuts….extreme rain event due probably to GW.

    Indonesia dam burst kills dozens
    http://news.bbc.co.uk/2/hi/asia-pacific/7967205.stm
    …He said there had been heavy wind and rain overnight with many trees uprooted.

  4. paulm says:

    Southern Africa: Anglican Head Blames Floods On Climate Change
    Cape Town — The floods ravaging Angola and Namibia are a further illustration of the urgent need to tackle global warming, the head of the Anglican Church in Southern Africa, Archbishop Thabo Makgoba of Cape Town, said on Tuesday.
    http://allafrica.com/stories/200903240852.html

    “We have had enough of talking. The international community cannot continue to prevaricate while countries like ours are increasingly suffering inestimable human cost, in deaths, displacement, and the destruction of livelihoods.”

    Northern Namibia is experiencing the worst flooding in decades, as is southern Angola. This year has already seen serious storms, flooding and loss of life in Gauteng and Kwa-Zulu Natal in South Africa, as well as in Mozambique.

  5. Ronald says:

    Why has science journalism declined in the years? Because in some subjects it’s so hard to do. Write about astronomy, you can see the big planets and stars in photographs. Write about most everything else, the evidence is easier. But global warming, that’s something that takes hard to do.

  6. paulm says:

    Extreme Tornado events 1950 – 2007

    http://www.wunderground.com/climate/extreme.asp

  7. paulm says:

    Obama cites North Dakota floods in call for climate change action
    http://www.sciam.com/blog/60-second-science/post.cfm?id=obama-cites-north-dakota-floods-in-2009-03-25

    “If you look at the flooding that’s going on right now in North Dakota and you say to yourself, ‘If you see an increase of two degrees, what does that do, in terms of the situation there?’” Obama told reporters at the White House Monday. “That indicates the degree to which we have to take this seriously.”

  8. You selected the perfect photo. Even a dog knows something is very wrong.

  9. AB says:

    Part of the problem with these extreme rain events is that they not only produce more rain fall, but that the amount of additional runoff and stream flow they cause does not increase in a simple linear fashion. Once the ground is saturated, everything that falls after that goes straight to the rivers. Many people seem to just look at the overall average precipitation for an area and see a relatively slight increase, thereby misunderstanding the nature and magnitude of the problem. The significant factor is what is discussed in the post: extreme rain events.

    See Jha, M., Z. Pan, E. S. Takle, R. Gu, 2004: Impact of climate change on stream flow in the Upper Mississippi River Basin: A regional climate model perspective. Journal of Geophysical Research., 109, D09105, doi:10.1029/2003JD003686.

  10. Will Koroluk says:

    A municipal engineer I know says he now routinely designs increased capacity into storm-sewer plans. The bigger storm events are coming around oftener than they used to in my part of Canada, so he now must specify larger pipes to accommodate flows that are bigger, oftener than they once were. He tells me that most municipal engineers he knows are doing the same thing.

  11. Brodie says:

    To add to what AB has said, it is especially more significant in winter months do to the lack of vegetative transpiration. Water that would otherwise be taken up by plants simply goes directly through the basins and into the channels. They’re likely to have massive soil erosion from this event as well.

    Recurrence intervals always seem to confound people. It’s just the odds that a flood level will be achieved in a given year. They’re based on observations and extrapolated data (Rainfall rates, drainage area density, hydraulic geometry, etc). I expect many of those R.I. graphs will be getting updated..

    Joe, I realize this is more focused on tropical weather, but perhaps Soden et al (2008) is relevant here as well.

  12. Jay Alt says:

    Snow hydrologist has studied the problem for years –

    http://npat.newsvine.com/
    Top 10 big floods on the Red 3/12
    Will there be another spring flood on the Red River? 2/5

    http://www.mnforsustain.org/
    climate_snowmelt_dewpoints_minnesota_neuman.htm

    Pat was fired for doing that work (on his own time), taking it to a conference against his supervisor’s wishes (at his expense) and speaking to Dan Rather. This happened in 1999 & 2000.

  13. Pangolin says:

    Well, there’s one house that’s not going to be using boiler oil next winter. While Fargo N. Dakota isn’t exactly a huge chunk of US greenhouse gas emissions the likelihood of displaced residents rebuilding houses that are worse emitters than those destroyed in the floods is slim. Like Greensburg Kansas there should be some inclination to build things “right” this time.

    A large portion of the displaced will move to other urban areas reducing their GHG impact as they transition from rural to urban life; single family to multi-family housing. Another portion will ‘double-up’ with family and reduce a portion simply by sharing walls and heating bills with others. US average occupancy is 2.6 persons per residence and average house size is over 2000 sq. ft.. That’s a lot of room for sharing with relatives.

    I think we’ve found the sharp end of Pangolin’s patented disaster wedge.

  14. Brodie says:

    Actually, I guess that should be Allen et al (2008)
    http://www.sciencemag.org/cgi/content/abstract/1160787

  15. papertiger says:

    Global warming er climate change eh hem, extreme weather events (yeah, that’s the ticket – let’s see Limbaugh refute that one!) will drive you out of your happy home and end civilization as we know it, unless we all switch to windmill power produced by government subsidized companies, like Joe Romm’s employer(s).

    One problem. More rain = more fresh water = a good thing.

    Most non ecozealots realize this fact.

  16. DB says:

    Studies by Kunkel et al. have found that the frequency of high precipitation events were equally high in the period 1895 – 1905, so an event such as Fargo isn’t something unusual, although it can be used as a poster child.

    Temporal variations of extreme precipitation events in the United
    States: 1895 – 2000
    http://www.cfa.harvard.edu/~wsoon/DaveLegates03-d/Kunkeletal03grlextremeinUSA.pdf

  17. barryjo says:

    A few thoughts on the flooding in North Dakota. First of all, the Red River valley runs through glacial Lake Agassiz. At one time, this lake held more water than all the worlds lakes today combined. (Wikipedia) The area is very flat. Land use practices in the valley have made rapid water runoff a necessity. Most of the water is coming overland. From melting snow. And since the ground frost is still present, no water is being absorbed. This has been an ongoing problem for decades. They have not come up with a goood, permanent way to divert the water around the towns. Temporary dikes and sandbaging are not solutions. And as long as people insist on living next to water, they will continue to get wet. 45 years ago, south of Fargo, an area called Oxbow was being develpoed. It is in the flood plain. It floods. But did the politicians prevent development? NO!
    And as far as large numbers of people fleeing the area, forget it. If 1% were to leave, it would be a surprise.
    The only cause of the flooding is lots of snowfall during winter and warm weather in the spring, causing an accelerated melt. That and more people living closer to water. Be honest, if this flooding were to be occuring over unoccupied land, little would be said. And AGW has nothing to do with it.

    [JR: Huh? "The only cause of the flooding is lots of snowfall during winter and warm weather in the spring, causing an accelerated melt.... And AGW has nothing to do with it." You can't be serious.]

  18. Over-attribution of global warming to specific events can be counter-productive. There are many factors at work in Midwest flooding, including changes in land use. Improvements in field drainage increase runoff from farmland and over-development in flood plains increases the impact of high flow levels. Although the country as a whole was near to above average in temperature for the winter, the upper Midwest and Great Lakes areas were particularly cold from North Dakota through Ohio. Since the Red River runs northward into Canada, the flooding is aggravated by the still-frozen downstream areas impeding the flow.

    Global warming does imply an enhanced hydrologic cycle, but excessive attention to individual events with complex causes undermines the legitimate case for action by inviting charges of hysteria. A local (Washington DC) TV weathercaster, NOT one of the knee-jerk deniers, declared yesterday that the flooding was not attributable to global warming.

  19. Looks like barryjo made my case while I was typing. “And AGW has nothing to do with it.” That statement is just as wrong as “AGW has everything to do with it.”

  20. MarkO says:

    barryjo, so you think the flood is caused by run off over frozen ground. DUH! You are overlooking a key fact that you nearly state yourself. It’s the flat terrain. The area is experiences SIX TIMES the amount of water from the prior record flood to get these flood levels. SIX TIMES! To state that it’s not unusual is delusional thinking.

  21. barryjo says:

    MarkO: How did you come up with “six times the amount of water”? 1997 flood level was about 37 feet. And my statement was to differentiate overland flooding from river overflow. What is happening there also happens in New Orleans. More levies and dikes force more water into a narrow channel. And since the topography is flat, something has to give. And Mother Nature doesn’t like to be forced!
    OK, CC. Then I will state this flooding cannot be attributed to AGW. Better?
    And that goes for the Cedar Rapids, IA flood of last year, also.

  22. DB says:

    “More levies and dikes force more water into a narrow channel. And since the topography is flat, something has to give.”

    Indeed. This paper by Pinter et al. last year looked at floods in the Mississippi River system and concluded that “the largest and most pervasive contributors to increased flooding on the Mississippi River system were wing dikes and related navigational structures, followed by progressive levee construction.”

    Flood trends and river engineering on the Mississippi River system
    http://www.agu.org/pubs/crossref/2008/2008GL035987.shtml

  23. Arthur Smith says:

    I had a post on essentially this topic last month:

    “If you look beyond the average at standard deviation and the distribution of extreme weather, then there is reason to claim just one or two years as evidence for a change in climate. If under the old climate a particular weather event had only a 1 in 10,000 chance of occurring, then its presence even in a single year is strong evidence that climate has already changed and there’s no need to wait 30 years to make the assertion. Any piece of data that is several sigma’s away from the norm can be evidence of a change, whether warming or cooling.”

  24. Dean says:

    It’s always easier to determine causes when “all else remains the same.” If our society would cooperate with researchers, then we would not change anything in our lives ;) and that would make it easier to determine if extreme weather events are contributing to more flooding.

    But obviously life goes on and clearly changing land-use patterns contribute to flooding. But that certainly is not proof that changing land use patters are the sole cause of increased flooding.

    The U.S. Extreme Climate Index graph at the beginning of this post demonstrate the plausibility that it isn’t just land use. The cite in DB’s post says that engineering structures are a larger factor than climate, but that climate is a part of it – and that is just for the Mississippi. As an intensely used shipping corridor, clearly the Mississippi has a lot of construction on it.

    But we have been learning a lot about how dikes and other structures contribute to flooding and at least some areas have been putting those lessons to good use. That would suggest that over the years, climate could become a relatively larger part of the cause if we don’t learn our lessons in that arena.

  25. John Mashey says:

    Arthur:I don’t disagree with you, except that I’m afraid the statistics of rare events are not compelling enough to most people. I much prefer the statistics of frequent events, or of things like all the bioscience indicators.

    But: for anyone, here’s a little thought experiment to explain how *shifting a distribution* as AGW does:
    a) Cannot be said to cause an specific event.
    b) But makes such events more likely.

    Suppose you flip a fair coin 40 times, and any time there are 6 heads in a row (moderately rare), it is a relatively rare event, called a flood. Suppose you weight the coin so that the chance of a tail goes from .5 to .45. More disasters happen. Of course, if (by doing bad land use), you decide that even 5 heads is a disaster, it will happen more often as well.

    In some sense, this simulates the kind of climate effect (like precipitation), where you can survive a lot of precipitation, but not many days of precipitation. Of course, in drought areas, it’s the reverse.

    Here’s a simple exercise via Excel:

    A1 = .5 (probability of a Tail)
    B1 = 2, C1 = 3, D1 = 4, E1 = 5, F1 = 6 # of heads in a row

    A2 = =IF(RAND()>A$1,1,0) coin flip, Head = 1, Tail = 0
    Fill down A2:A41

    B3 = =IF((SUM($A2:$A3)=B$1),1,0) Are there 2 heads in a Row? 1 = yes
    Fill down B3:B41

    C4 = =IF((SUM($A2:$A4)=C$1),1,0) Are there 3 heads?
    Fill down C4:C41

    D5 = =IF((SUM($A2:$A5)=D$1),1,0)
    Fill down D5:D41

    E6= =IF((SUM($A2:$A6)=E$1),1,0)
    Fill down E6:E41

    F7= =IF(SUM($A2:$A7)=F$1),1,0)
    Fill down F7:F41

    G8= =IF(SUM(#A2:$A80=G$1,1,0)
    Fill down G8:G41

    A42 = =SUM(A2:A41)
    Fill right A42:G42
    ===
    A2 is total heads
    B42 is number of heads (1s) in which previous cell is a Head

    G42 is number of heads in which 5 previous cells are Heads, i.e., 7 in a row.

    Any time B42:G42 is >0, think of that as a year in which at least once, there was a sequence of precipitation days of some size.

    Now, watch A42:G42 and repeatedly press F9, which regenerates the random numbers.
    Do this 20 times, and count the number of times G42 is >0, think of this as “year with really bad flood”, or count the number of zeroes between nonzero cases, i.e., maybe this something on the order of 10-year flood.

    Now change A1 = .4, i.e., decreasing the chance of a Tail, i.e., increasing chances of Head (precipitation).

    Press F9 20 times and see what happens.

    Now, that change to .4 did *not* cause any particular sequence of heads to happen, but it moved the distribution to make longer sequences of heads more likely, so maybe a 10-year flood becomes a 5-year-flood, or a 20-year-flood becomes a 10-year flood. the *whole* distribution moves.

  26. barryjo says:

    I don’t see that that proves anything. When flipping a coin, the odds that heads will come up are always 50/50. Regardless of how many times something has come up before. And just to make things interesting, Global warming is a natural, cyclical series of events. Been happening for millions of years. Adapt. All the discussion is centered around manmade global warming. Totally different topics. And just keep this in mind. 25 or 50 or 100 years, geologically speaking, is basically irrelevant.

  27. barryjo says:

    jr: I lived in the fargo area in the late 60′s. We used to watch the 10pm news as people along the river were running garden hoses into their basements, flooding them with clean water so stinky silty water would not enter. This has been going on since people started building near the river. Manmade global warming (if there is such a thing) is not the cause. Just about every year they have flooding. The only question would be how much. For some reason, people will build next to water and then whine when they get wet. The government builds a levee and more people build. It is a vicious circle. And heaven forbid they should pay for flood insurance.

  28. Bob Wallace says:

    “Global warming is a natural, cyclical series of events. Been happening for millions of years.”

    Each time the Earth has warmed or cooled there has been a reason. The cycles do not occur for no reason at all.

    ” Adapt.”

    We can adapt to some moderate change, either hotter or colder, but anything outside the moderate range will mean immense human suffering and the extinction of many plants and animals.

    If we allow the planet to go “runaway” we’ll lose most of the plants and animals and eventually all of us. We’ve seen global warming clean most life off the globe in the past.

    “All the discussion is centered around manmade global warming.”

    Well, duh.

    It’s ain’t the Sun or the Warming Fairy this time….

  29. Bob Wallace says:

    “For some reason, people will build next to water and then whine when they get wet. The government builds a levee and more people build. It is a vicious circle. And heaven forbid they should pay for flood insurance.”

    So, you’re way of thinking is that everyone in the world who lives less than 30 higher than sea level should get busy building dikes?

    And find a company willing to sell flood insurance?

    Makes (no) sense to me….

  30. MarkB says:

    BarryJo writes: “The only cause of the flooding is lots of snowfall during winter”

    Actually, more frequent heavy precipitation events is a result of global warming. This means more snowfall in the north during winter months.

    “and warm weather in the spring, causing an accelerated melt…. ”

    With global warming, we have observed a trend towards earlier spring runoff.

    Obviously, annual variability and weather patterns are a primary driver in such events as the recent record-breaking flood, but global warming is gradually raising the risk that such events will occur.

  31. mauri pelto says:

    jay Alt is right Pat Neuman is the expert, I emailed him yesterday for his analysis. Let us just guess at the flood cause barryjo, why look at the data for the month.
    If you look at Fargo data
    http://www.crh.noaa.gov/fgf/scripts/localdata.php?loc=appcli&data=bislcdfar
    You will note that the snow depth was not that substantial. From the 15th to the 17th considerable melting did occur. But is the warm spell after most of the snow melted on the 22nd to the 25th that provided considerable rainfall to push the spring snowmelt heightened rivers. This amount of rainfall in other areas would not raise eyebrows, but this is at the start of spring in North Dakota. You can also look at the snowpack maps, this happens to be todays, but they exist for everyday for the area.
    http://www.crh.noaa.gov/ncrfc/content/seasonal/snowdata.php
    If you look at Pat Neuman’s list of previous flood events on the Red River that Jay refers to http://npat.newsvine.com/. You will see this is the first in March, hmmm.

  32. DB says:

    “Actually, more frequent heavy precipitation events is a result of global warming. This means more snowfall in the north during winter months.”

    If true, then that is good news for those concerned about water stress in the west and in Asia. More snow means more snow pack which means more runoff during the warm months.

    [JR: Quite, quite wrong. Also "the west" is a big place. the Southwest will become a permanent desert post-2050 on our current emissions path. The snowpack has been melting away sooner, which has measurably reduce runoff during the hot dry months.]

  33. DB says:

    “The U.S. Extreme Climate Index graph at the beginning of this post demonstrate the plausibility that it isn’t just land use.”

    Studies by Kunkel et al. have found that the frequency of high precipitation events were equally high in the period 1895 – 1905, so it would appear an event such as Fargo isn’t something unprecedented.

    Temporal variations of extreme precipitation events in the United
    States: 1895 – 2000
    http://www.cfa.harvard.edu/~wsoon/DaveLegates03-d/Kunkeletal03grlextremeinUSA.pdf

  34. Neil Hampshire says:

    I’m sat here in the UK.

    The floods have obviously been a once in a lifetime event, but I haven’t seen anything in the news reports about heavy rain.

    Surely you must at least be able to agree amongst yourselves. Was it melting snow or heavy rain?

  35. barryjo says:

    DB:FYI. I just heard on the news that the previous record flood level at Fargo, ND was 40.1 feet. That flood record was in 1897. Yes, they had a flood in 1997. But the previous record was set in 1897.

    And I wish people would stop confusing Global Warming and Anthropogenic Global Warming. They are not the same!

    [JR: In common usage, GW and AGW are interchangeable.]

  36. Jim Bullis says:

    It seems like a waste of energy to talk about a flood that is now equal to a flood 110 years ago as demonstration of global warming.

    The average situation is important. This is not important information.

    Making a big thing of this flood sort of weakens the case that there is a solid and steady problem underlying the whole climate thing.

    This kind of thing actually slowed my progress.

  37. Jim Bullis says:

    Correction,

    You have covered the matter satisfactorily with the extremes index chart, which gets beyond the “this flood proves it” level of discussion.

  38. John Mashey says:

    mauri & Jay Alt: thanks for the pointers, very useful.

    Anyone who wants to understand this topic:
    IPCC AR4 WG I, Chapter 3 is useful, see especially p.399-316 (Section 8.2 – Changes in Extreme Events).

    In particular, the little Monte Carolo Excel simulation I suggested was trying to illustrate examples like Figure 3.38 or Box 3.6, Figure 2, i.e., where some effect shifts a ~Bell-shaped-like distribution, i.e., one with most of the data in the middle with a few outliers.

    People naturally focus on rare extremes, and they are very important for engineering, but statistically, they are often poor indicators.
    The “record” flood level can be a very confusing metric, because it is, by definition, a rare event. If you have a Bell-shaped curve, and you move it, (as in Box 3.6, Figure 2), it may take a while before setting a new record, but (in that case, temperature), warmer temperatures are much more frequent.

    For example, would all be well if the Fargo flood level didn’t set a new record (>40.1) for 10 years … but the frequency of 38-40.0 events rose strongly?

    As for snowpack & water, highly relevant to South Asia and Western US, and both the temperature pattern and total precipitation matter.

    a) We depend on a long buildup of snowpack, and a slow release, like here in CA. The Sierra snowpack acts like a huge set of dams … whose release schedule we don’t control.

    b) As it warms, more falls as rain, and the snow that does exist melts faster, so the result is a “spike” in flow, i.e., floods. Then, if the amount of precipitation is the same, less of it is left in the snowpack to take care of August and September. One can have flood, and then drought in the same year. Spikes are bad.

    c) In some areas, the net effect is to make it rain less in the South and more in the North. Sometimes one can move the water [in CA, 20% of the state's electricity is used to move water around, a lot of it from the North where the snowpack is, to the South, where the people are.] Los Angeles also uses the Colorado River.

    d) In the West: “Whiskey is for drinking, water is for fighting.”
    If applied to the Himalayas, which yield water for much of South Asia, the fighting part could get serious. While Northern China could sure use more rain, moving it there won’t help India much.

  39. barryjo says:

    JR: To assert that AGW and GW are the same “in common usage” is to totally muddy the issue. And that is probably the reason it is done. Global warming is natural, cyclical and has been going on for millions of years. By its very definition, AGW is controlled by mankind. And the basis of AGW is that CO2 is causing the change. Even if that were to be proven, they would still be separate.
    My contention is that looking back a couple hundred years and making decisions based on any trends therein is quite myopic.

  40. John Mashey says:

    barryjo:
    I’m interested in understanding why people believe what they believe, so the following are straightforward questions for which there are no right answers. I’m just curious.

    Can you give us some background as to why your opinion should carry weight with people who don’t know you? “barryjo” is effectively anonymous.

    Have you studied books on this topic by real climate scientists?
    - If so, which ones do you regard highly?

    Read peer-reviewed scientific journal articles on climate?
    - If so, whiich journals and articles do you find useful?

    Attend lectures by climate scientists and talk to them?
    - If so, who impresses you? [This one of course is location dependent.]

  41. Bob Wallace says:

    “b) As it warms, more falls as rain, and the snow that does exist melts faster, so the result is a “spike” in flow”

    John – is it not likely that the ‘rain rather than snow’ reduces the amount of water that gets below the surface to recharge the aquifer?

    I live in the CA coastal mountains and depend on my fractured rock mountain to soak up a lot of water and recharge my well for the summer garden. When we get a nice big snow I see little run off, the snow gradually melts and soaks in. Rains quickly run to the sea.

    Declining aquifers are a major problem in much of the country.

  42. Bob Wallace says:

    “Surely you must at least be able to agree amongst yourselves. Was it melting snow or heavy rain?”

    Neil – I did some searching but found nothing definitive.

    The best I found is that the ground is very saturated due to a lot of precipitation this year. And it’s largely frozen, which means that it won’t accept more. Finally there have been some very large snowfalls recently.

    Let me add a guess that the Mid West might be experiencing some large temperature swings. That’s certainly happening where I live on the west coast. Big snows followed by some “unseasonable” warm weather would release a lot more water than would gradual spring warming.

    Perhaps someone else has more facts….

  43. Neil Hampshire says:

    Thanks Bob. I have also found that ice jams seem to be a problem On a Fargo site I found “Ice derived from the southern Valley progressively meets with freshly-broken ice in the central and northern Valley. Ice concentrations in this regime can only build, retarding or damming water flow.”

    If as you say the ground is largely frozen and there is a build up of ice downsteam which is preventing free flow of water we should conclude the unusually cold and snowy winter must be something to do with this event.

  44. DB says:

    “f as you say the ground is largely frozen and there is a build up of ice downsteam which is preventing free flow of water we should conclude the unusually cold and snowy winter must be something to do with this event.”

    Wouldn’t be surprised. Here in Chicago they’ve been keeping weather records for 140 years and this winter ranked in the top 10 for both snow and cold.

  45. John Mashey says:

    Bob Wallace:
    Rain rather than snow: probably, but I think the main issue is the spikiness of precipitation (rain vs snow+melt).

    I.e., even if no snow is involved, there can be a big difference between:
    a) A huge rainstorm, which causes a lot of runoff.
    b) The same total inches of rain, spread over many weeks.

    Snow+slow melt ~ b), but snow + fast melt is more like b).

    Of course, this is a particular issue for you & I in CA, but further North, they worry about it in Washington. But at least, they tend to get some rain up there in the summer, unlike down here. Given the amount of agriculture on the West Coast, this is serious.

  46. David B. Benson says:

    barryjo — On a scale of millions of years, the world has been in a gradual cooling trend; the reason is that geochemical changes slowly remove CO2 from the active carbon cycle. On a scale of hundreds of thousands of years, there have been the swings between glacial and interglacial due to orbital forcing; baring AGW the globe would slowly be heading towards another attempt at a stade (massive ice sheets) in about 20,000 years.

    The excess carbon added by humans to the active carbon cycle since the start of the industrial revolution has completely upset all of that; GW = AGW.

  47. DB says:

    “Actually, more frequent heavy precipitation events is a result of global warming. This means more snowfall in the north during winter months.”

    “If true, then that is good news for those concerned about water stress in the west and in Asia. More snow means more snow pack which means more runoff during the warm months.”

    [JR: Quite, quite wrong. Also “the west” is a big place. the Southwest will become a permanent desert post-2050 on our current emissions path. The snowpack has been melting away sooner, which has measurably reduce runoff during the hot dry months.]

    If one looks at the Colorado River, the major water source for the southwest, it’s basin extends up into northern Colorado and Wyoming. Snow totals are readily available for the ski resorts. Vail, for example, has had 371″ of snow this winter while a normal year is only 184″ Having twice as much snow pack means a lot more water for the southwest this year.

    [JR: Try again.]

  48. barryjo says:

    OK, JR. lets try some more questions. David B. Benson says “On a scale of hundreds of thousands of years, there have been the swings between glacial and interglacial due to orbital forcing; barring AGW the globe would slowly be heading towards another attempt at a stade (?) (massive ice sheets) in about 20,000 years.” That would be the definition of cyclical.
    Then he writes “The excess carbon added by humans to the active carbon cycle since the start of the industrial revolution has completely upset all of that; GW=AGW.”
    So which is it? On the one hand we are emitting carbon that is heating the planet, and on the other, emitting carbon is slowing or stopping another iceage.
    Please enlighten me.

    [JR: The climate changes when it is forced to change. Historically that has been driven by either large emissions of greenhouse (or other) gases or changes in the Earth's orbit, which provide a small initial warming that triggers amplifying feedbacks and the carbon cycle. Many scientists believe that absent human action, we would over the course of the next few thousand years slowly enter in another ice age. The greenhouse gases we are emitting at a rate 200 times faster than has ever occurred during the natural, amplifying cycles, have overwhelmed the slow cooling we might otherwise be experiencing and driven us into a rapid warming cycle.]

  49. John Mashey says:

    barryjo:
    Good, I see you’re back. Want to try the questions I asked March 28, 5:57PM?

    JR: note that there is a *lot* of confusion about the term “ice age”.
    I know you know all this, but to remind everyone to think about what “entering an ice-age” means:

    Looking at ice age volume, we have, looking at the *last* ice age:

    A: the (usual) point of highest temperature, after which the temperature slowly lowers, with jiggles, say ~120K years ago.

    B: (slightly later, normally) the point of *Lowest* ice volume, after which the ice slowly expands, with jiggles.

    C: at some point, Toronto’s location (to pick an intermediate example) was covered with ice

    D: Finally, temperatures reached their lowest point, and ice its maximum extent. Then Milankovitch takes over… temperatures rise, CO2+water vapor amplification cut in, then ice-albedo feedback, and temperature rises quickly, and ice disappears

    Now, I don’t think anyone would consider point A the beginning of the ice age this time, as the Holocene entirely follows that. Ruddiman thinks (in Plows, Plagues & Petroleum) that there were signs of an incipient rebuild of ice cover in Baffin Island, but of course, the glaciers are not advancing now.

    Anyone would agree that C & D are parts of a real Ice Age, but the widely-used phrase “heading back to an ice age” seems meaningless, since it often takes 10s of thousands of years, even naturally.

    Of course, as seen in 5Myear chart, in the last ~3Myears, the Earth has been in a hair-trigger state that allows these big swings, which only happens with the right continental configurations and CO2/CH4 levels. Since Milankovitch cycles aren’t going to change, and continents don’t move that fast, we certainly could return to the right side of that graph where there is little ice on the planet.

    Of course, if we ever really faced an icea age, and still had a tech civilization, we could probably fix that with some long-lived, intense GHG like SF6…

  50. DB says:

    If one looks at the Colorado River, the major water source for the southwest, it’s basin extends up into northern Colorado and Wyoming. Snow totals are readily available for the ski resorts. Vail, for example, has had 371″ of snow this winter while a normal year is only 184″ Having twice as much snow pack means a lot more water for the southwest this year.

    [JR: Try again.]

    OK, could you explain why, if the mountains of Colorado and Wyoming have twice as much snow at this time than they do normally, the Colorado River won’t deliver more water to the reservoirs of the southwest?

    [JR: Early snowmelt kills off the rivers before they are most needed.]

  51. Chris Dudley says:

    The thing about this flood that pushes it towards attribution for me is that it comes about a month earlier than other big floods. One wants to look into this in more detail but the early runoff from early snow melt seems similar to the snow pack issues related to warming in the Rockies and Sierras which are squeezing the water supply in the West. Timing seems to be important here as well. If it is the case that with the same snow pack but a longer melt period, floods have been avoided in the past then a warming induced early melt could be thought of a causal.

    We still don’t have the fine grained modeling to have predicted this so that we need caution in after the fact assertions, but this does have the smell of an attributable event.

    BTW, theres an attribution study that links the deadly European heat wave to warming so some scientists are willing to link some individual events. One just needs to be pretty careful.

  52. You have a lot of good information in your posts. I want to add that cold weather is also a possible indicator of overall warming, due to the way that cold and warm fronts work.

    If a certain area becomes very warm, another area can become very cold, because of the speed that intense weather pushes cold and warm fronts around the world.

    You do a lot of good research so it might make a good topic for you to write about.