A new perspective on drought in the American southeast

by Judith Curry

Imagine that you are planning for water resources in the greater Atlanta region for the next 50 years.  Which information would be more helpful:

A.  Global climate model simulations for the 21st century that are downscaled for the region

B.  Paleoclimatic analysis for the last 400 years of droughts and wet periods.

The CMIP3 climate models used in the AR4 basically tell us nothing about future rainfall in the 21st century for this region, other than that the different model runs don’t agree.

If you are wondering what we might learn from B, take a look at this recent article.

A long-term perspective on a modern drought in the American southeast

N Pedersen, AR Bell, TA Knight, C Leland, N Malcomb, KJ Anchukaitis, K Tackett, J. Cheff, A Brice, B Catron, W Blozan, J. Riddle

Abstract.  The depth of the 2006–9 drought in the humid, southeastern US left several metropolitan areas with only a 60–120 day water supply. To put the region’s recent drought variability in a long-term perspective, a dense and diverse tree-ring network—including the first records throughout the Apalachicola–Chattahoochee–Flint river basin—is used to reconstruct drought from 1665 to 2010 CE. The network accounts for up to 58.1% of the annual variance in warm-season drought during the 20th century and captures wet eras during the middle to late 20th century. The reconstruction shows that the recent droughts are not unprecedented over the last 346 years. Indeed, droughts of extended duration occurred more frequently between 1696 and 1820. Our results indicate that the era in which local and state water supply decisions were developed and the period of instrumental data upon which it is based are amongst the wettest since at least 1665. Given continued growth and subsequent industrial, agricultural and metropolitan demand throughout the southeast, insights from paleohydroclimate records suggest that the threat of water-related conflict in the region has potential to grow more intense in the decades to come.

Citation:  Environ. Res. Lett. 7 (2012) 014034 (8pp) [link] to abstract  (if you would like a copy of the paper, send me an email:

The Introduction provides some context for the decision making problem:

Drought is a pervasive phenomenon throughout much of North America with profound ecological and societal implications.  Although much attention has been devoted to forecasting the frequency and magnitude of drought in semi-arid western North America, recent moisture deficits in the southeastern US have renewed water management challenges that underscore the need to better understand drought processes in humid, subtropical regions.  Notably, the droughts of 1986–8, 1998–2002 and 2006–9 caused severe crop damage, disruptions in electricity generation and water shortages, which prompted water restrictions and multi-state legal conflicts . This is particularly evident in the state of Georgia, where droughts during the 1980s and 1990s occurred concomitant with a 50% increase in population and a 35% increase in groundwater withdrawal. During the 2006–9 drought, many municipal water supplies throughout the region, including Atlanta, were reduced to 60–120 day capacities.

Given recent water shortages and emerging challenges, Georgia and adjacent states have revised water management plans to include greater focus on conservation and efficiency. Unfortunately, many water allocation plans are based on limited 20th century records and capture a narrow range of potential moisture variability. To plan for an expanded range of natural and anthropogenically forced variability, water managers have begun to incorporate tree-ring based hydroclimate reconstructions to place recent droughts in a long-term context. Tree-ring based perspectives suggest that the 20th century has been relatively moist with respect to the last millennia in the eastern US and that although recent droughts have had significant societal implications, they are in most cases less severe relative to prior centuries.

From the Conclusion:

The latter 20th century instrumental data, upon which regional water supply management decisions are based, is characterized by frequent wet events that are not representative of much of the prior 300 yr. Investigations of long-term drought in other regions of the southeastern US have similar findings: the 20th century appears wetter in the context of the last 400–1000 years…..The climatic patterns revealed here—the pervasively drier 18th century, the weak wet periods of the 19th century, and the high frequency of extreme drought in the early 18th and 19th centuries—provide valuable baseline scenarios for simulation of inter-annual climate variability and water resources planning that do not appear in the more recent, relatively wetter instrumental records. Although non-stationarity of the climate system could cause climate variability to differ from what has occurred historically …..this reconstruction provides a broader representation of the potential range of climate variability than is available from the instrumental record alone, and thus is a valuable tool for understanding the context of extreme events to which our infrastructure must be able to adapt.

JC comment:  IMO, studies such as this provide much more useful information for regional decision making than do climate models.  The amount of rainfall variability on decadal and multi-decadal time scales is far greater than anything that has emerged from 21st century climate model simulations.

Interesting that this paper uses tree rings to infer rainfall rather than temperature.  As far as I can tell, the authors have a very good reputation and the methods used in this paper are sound.

119 responses to “A new perspective on drought in the American southeast

  1. We were offered choices A and B. I will go for choice C, which stands for Curry and her presentation at the Boulder, Colorado NOAA workshop on water in August, 2011. Look at slides 8. 9 and 11 to see the slim probability of drought in the USA southeast.during the next dozen years.


    • Don,

      Having pinned my standard to the mast predicting US drought again just yesterday – I suggest that you may have not grasped the complete implications for water availability in the US.

      ‘Positive AMO conditions (warm North Atlantic SSTs) since 1995, and the cold PDO episode from 1998 to 2002, have together raised concerns among scientists about the potential for an emerging megadrought that could pose serious problems for water planners.’ McCabe et al 2004

      The PDO has of course turned decidedly negative in the interim.


  2. A similar evaluation was recently published for my area-

    Duration and severity of Medieval drought in the Lake Tahoe Basin

    J.A. Kleppea, D.S. Brothersb,*, G.M. Kentc, F. Biondid, S. Jensene, N.W. Driscollf

    a College of Engineering, University of Nevada, Reno, MS 256, Reno, NV 89557, United States

    bWoods Hole Coastal and Marine Science Center, US Geological Survey, 384 Woods Hole Rd, Woods Hole, MA 02543, United States

    c Seismological Laboratory, University of Nevada, Reno, MS 174, Reno, NV 89557, United States

    d DendroLab, University of Nevada, Reno, MS 154, Reno, NV 89557, United States

    e Department of Earth and Planetary Sciences, Northwestern University, 1850 Campus Drive, Evanston, IL 60208, United States

    f Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United States

    published in the Quaternary Science Reviews in November 2011.

    a b s t r a c t

    Droughts in the western U.S. in the past 200 years are small compared to several megadroughts that occurred during Medieval times. We reconstruct duration and magnitude of extreme droughts in the
    northern Sierra Nevada from hydroclimatic conditions in Fallen Leaf Lake, California. Stands of submerged trees rooted in situ below the lake surface were imaged with sidescan sonar and radiocarbon
    analysis yields an age estimate of w1250 AD. Tree-ring records and submerged paleoshoreline geomorphology suggest a Medieval low-stand of Fallen Leaf Lake lasted more than 220 years. Over eighty
    more trees were found lying on the lake floor at various elevations above the paleoshoreline. Water balance calculations suggest annual precipitation was less than 60% normal from late 10th century to
    early 13th century AD. Hence, the lake’s shoreline dropped 40e60 m below its modern elevation. Stands of pre-Medieval trees in this lake and in Lake Tahoe suggest the region experienced severe drought at
    least every 650e1150 years during the mid- and late-Holocene. These observations quantify paleoprecipitation and recurrence of prolonged drought in the northern Sierra Nevada.



  3. I would only say that caution should be exercised in the future=past assumption.

    • I agree, but how should that caution be exercised? Dams must be built to a specified height. How shall we specify it? When it comes to construction, there is no room for uncertainty. Just as with most policy decisions.

      • For example, extreme warmth in summer (three-sigma events) is already becoming ten times more common than in the 20th century (not models, but statistically). Planning should account for that at least, and not use 20th (or 19th or 18th) century statistics for planning. The view of the original post advocates ignoring ongoing trends, which is specifically where I differ,

      • But as most of 20th century warming entirely natural – most of that prior to 1945 and at least half after 1976 – what is the significance? There are many ways to obtain the latter result. My favourite is to remove the ENSO dragon-kings in 1976/77 and 1998/2001 as Kyle Swanson did in this realclimate post.


        Let’s think about the headline for a moment. ‘Warming interrupted – much ado about natural variability. Says it all really.

        I disagree by the way – the satellite evidence suggests cloud radiative forcing was by far the dominant warming effect between 1979 and 1997. ‘To the extent that they are real, they may simply reflect natural low-frequency variability of the climate system.’ AR4 S3.4.4.1

        You as well misrepresent the paper by claiming that it ignores ‘trends’. It captures climate data over longer periods and finds that recent droughts are certainly not unprecedented.

        Given that multi-decadal variability is a fact of life – any trend over less than a few hundred years at least is a statistical nonsense. Indeed projecting a so called late 20th century trend into the future in the light of a dynamically complex system (see Swanson again) that has experienced major changes in the Holcene is absurdly optimistic.

      • It comes down to how much of the warming you think will be reversed as the CO2 added in the 21st century is 500% that added in the 20th. To me, it is certain we have seen the 20th century global temperature values for the last time. Cloud reduction could equally, possibly more likely, be considered a positive feedback response to the changing forcing rather than a coincidental completely independent effect.

      • I will first of all suggest that the energy mix in 2050 will be radically different to today’s as resource costs drive innovation and efficiency. In the interim there are many approaches that are not only theoretically possible but are proceeding in the real world. Health, education, economic development and safe water and sanitation amongst the ways to improve conservation and reduce population pressures. Conservation farming on grazing lands leading both to production increases and carbon sequestration. So I think you are far too alarmist. Look at the positives and stop inventing potential catastrophes.

        Again – there is nothing to support either positive or negative feedbacks in clouds from warming (that has been mostly natural) and handwaving about likelihood will not change that. It must be remembered that Dessler was an ENSO feedback and Clements a PDO feedback.

        And as realclimate puts it – warming interrupted: much ado about natural variability – the world is not warming for a decade or three because the system is dynamically complex and shifts every few decades. Which is indeed the bigger risk – risk being the convolution of consequence and probability.

        Give it up Jim – it is all falling apart and there is nothing you can do to rescue the AGW meme. The new paradigm you need to embrace is dynamical complexity in the climate system.

  4. I vote for (c) chicken entrails.

    Past precipitation, to the extent that it can be accurately reconstructed (and that’s a big caveat) provides information on natural variability. What it doesn’t do is tell us why. So, in a chaotic system, it has no predictive power.

    It is useful to know about the Dustbowl of the 1930s and the devastating Federation Drought in Australia around the beginning of the C20th, because it reminds us that these things have happened without human intervention in the past, and also that they came to an end naturally. But we don’t know why they happened in any sense that is meaningful for predictive purposes.

  5. Willis Eschenbach

    Thanks, Judith, most interesting. I have long held (based on similar studies elsewhere) that there are more droughts during cold times than warm times, which seems to be borne out by this study.

    And yes, trees are much better at indicating droughts than they are at telling the temperature. My bible on this question is the work of Fritts, “Reconstructing Large-scale Climatic Patterns from Tree-Ring Data”, published in 1991. He’s a bit optimistic on the ability of trees to tell the temperature, but other than that it’s a fascinating book.


    • Frankly, 400 years of data are not more useful than 200 years of data in this context – and 200 years of data already exist in meterological and historical records.

      When planning infrastructure, one does not plan for 1 in 400 year events – it results in over-engineering and waste. We do not design buildings in case there is another LIA, for example.

      My point is that the only benefit from either models or palaeo reconstructions, even if they could be relied on (which is far from proven), would be if they had some predictive value. We already know, in relation to water resource planning, the natural variability over the past couple of centuries sufficiently to assess what the precipitation range in the recent past is. While it is not perfect, it is the best indicator of future precipitation we have, and going back much further actually muddies the picture because of events like the LIA.

      Water planning is always a balancing act, and it is often impossibly expensive and wasteful to build infrastructure that gives 100% insurance against either extreme droughts or extreme floods. So, minus predictive power greater than what we can already extrapolate from the last couple of centuries, neither method is worth spending money on for planning purposes. At least you can barbeque the chicken!

      • Willis Eschenbach

        johanna | June 21, 2012 at 10:28 am

        Frankly, 400 years of data are not more useful than 200 years of data in this context – and 200 years of data already exist in meterological and historical records.

        You have 200 years of rainfall data for South Carolina? My goodness, that’s a huge breakthrough. Cite? …


      • Willis

        Britain is supposed to have the finest historical rainfall records in the world but in truth its extremely patchy and tends to be restricted to long inhabited places which tend to also be the most congenial ones-rather than the wettest.
        I too woud be interested in seeing 200 year old South Carolina records.


      • There are meterological records since 1895 cited here:


        “South Carolina has a warm, moderate climate with hot, humid summers. Rainfall records kept since 1895 show the statewide average annual rainfall is near 48 inches although it has ranged from 32 to 70 inches. Generally, the highest annual rainfall occurs in the northwestern portion of the state with winter and early spring months being the wettest and late summer and fall months being the driest.”

        Records of precipitation extremes go back to 1890:


        The first colony was established in 1670, and the State has been primarily agricultural for most of its history. There are ample diaries, newspapers and other historical records which describe the climate in particular years since agriculture began. (I did mention in my post the role of historical as well as meterological records). The frequency of major events like droughts and floods is no mystery.

        The point is, as the quote above shows, the rainfall parameters are very wide – from 32 to 70 inches annually, and the frequency and scope of major fluctuations for the last couple of hundred years is well known.

        I reiterate that the predictive value of past climate data decreases after a certain point, and is limited at the best of times. If you accept the existence of the Medieval Warm Period and the Little Ice Age, clearly the point of diminishing and quite likely misleading returns, while inexact, is most safely assumed to be less than 400 years. Indeed, the climate 400 years ago is most likely to have been measurably different.

      • Willis Eschenbach

        So in other words, johanna, your claim that “200 years of data already exist in meterological and historical records” wasn’t true … you could have just said that instead of waving your hands about diaries and the like.

        Look, it’s not bad to get caught making an exaggerated claim like that, johanna. But when you try to support a claim of “data” by reference to “ample” diaries and the like, by which I assume you mean occasional newspaper accounts and a few diaries, you just look foolish. Sure, they provide a snapshot of a few years … but we’re talking about rainfall data, which is hugely variable in both space and time. For that, we need actual statewide records, not what some farmer said in 1830 about “turrabal floods the worst in living memory” on his tiny plot of land. Those are called “anecdotes”, not data.


      • Please do not simultaneously condescend to me and misinterpret me. What part of ‘historical records’ is ambiguous? The SC State Climatologist, discussing the history of the State’s climate, regards historical reports of droughts in 1818 and 1848 as reliable, here:


        Here is just one piece of research into historical SC climate records before they were formalised:


        “Instrumental records [which date back 300 years], being conducted by the U.S. military, Signal Service, the medical community and volunteer observers.” This article (by Professor Mock of USC) reproduces examples of both newspaper charts and handwritten US military records from the 1860s, with, you know, proper columns for temperature and precipitation, dates and times, not scribbles in a smallholder’s diary. He says there is a heap of stuff in the State archives going back 300 years.

        It is simply untrue that we do not have a good idea of precipitation for the last couple of hundred years, or of temperatures either, for that matter.

        The snark about being caught out making exaggerated claims is completely uncalled for. Before I wrote my post, I spent 5 minutes on Google. It’s not obscure information. Next time you accuse someone of being wrong, I suggest that you do the same before launching one of your supercilious attacks.

  6. Pederson et al, 2006 also used dendro analysis to look at drought variability in the Northern Rocky Mountains, “Long-Duration Drought Variability and Impacts on Ecosystem Services: A Case Study from Glacier National Park, Montana.”

    “ABSTRACT: Instrumental climate records suggest that summer precipitation
    and winter snowpack in Glacier National Park (Glacier NP), Montana,
    vary significantly over decadal to multidecadal time scales. Because instrumental records for the region are limited to the twentieth century, knowledge of the range of variability associated with these moisture anomalies and their impacts on ecosystems and physical processes are limited. The authors developed a reconstruction of summer (June–August) moisture variability spanning A.D. 1540–2000 from a multispecies network of tree-ring chronologies in Glacier NP.”


  7. Willis Eschenbach

    johanna | June 20, 2012 at 9:11 pm | Reply

    I vote for (c) chicken entrails.

    Past precipitation, to the extent that it can be accurately reconstructed (and that’s a big caveat) provides information on natural variability. What it doesn’t do is tell us why. So, in a chaotic system, it has no predictive power.

    Thanks, johanna. While it has no predictive power, past precipitation can certainly tell us the size of natural swings that are possible in the longer term, and how frequent they might be … and to me, that’s useful information for anyone planning for the future. Beats chicken entrails hands down.


    • …beats casting ‘dem chicken bones over a generation — or even the 4 to 8 year presidential election cycle — or, are you thinking more long-term like maybe… 10 years? Because, in the looooong-term we’ll all be dead.

    • Dave Springer

      There’s a common disclaimer in financial statements produced by corporations where those statements include forecasts. Past performance is no guarantee of future performance. That’s a CYA statement meant to protect the company from misleading shareholders or potential shareholders.

      I add a caveat to that statement so that it reads “Past performance is no guarantee of future performance but it’s still the best predictor we have.”

      Or as someone whose investing acumen I respect told me many moons ago “In a clutch you want Michael Jordon to have the ball not the rookie”.

      • Not quite. Past performance is not even a good predictor of future performance in the stock market anymore than are sunspots. the highest correlation you can get about the future is what it is today. That’s as good as it gets. Other than that monkeys throwing darts do as well.

  8. “Interesting that this paper uses tree rings to infer rainfall rather than temperature. As far as I can tell, the authors have a very good reputation and the methods used in this paper are sound.”

    If regions low in rainfall this makes sense.
    It seems one could need older records, less 500 years one looking at LIA, and current global conditions are more similar to the warmer periods before this.

    • crosspatch

      Exactly. The only thing I got out of reading the article was “during the LIA, the Southeastern US was drier than it is now”. I would be more interested in the period 2000 to 1000 years ago.

  9. It seems pretty obvious that global models with zero regional accuracy will be worse than almost any reasonable regional approach to estimating precipitation variability. Past experience with papers using tree rings as thermometer readings for climate studies has not made me very confident that practitioners understand the statistical issues very well. But at the very least we know they aren’t committing the same kind of fallacies as the climate papers, because their results don’t produce constant estimates for rainfall in the pre-instrument era.

  10. Desalination can solve the fundamental problem of not enough fresh water. It is more expensive but it averts any Malthusian payoffs. Using nuclear power one can even do it carbon free.

    • Where will you put the salt? Throwing it back into the sea in high concentrations for generations is going to be an effect on the local ecology.

  11. The most helpful information you could give water resource planners in Atlanta would be… we don’t know enough to predict the climate two years from now, let alone 50.

    Then, and only then, would the rest be helpful, including the famously inaccurate climate models. There is nothing wrong with giving policy makers all the information available. The problem is when the “scientists” claim a level of certainty to which they have no real claim.

    Maybe the best information you could give them would be the telephone numbers of the Queensland, Australia planners who based their water retention policy on climate projections leading up to 2010-11. That’s assuming they learned their lesson.

  12. Atlanta has always been in a bad place. Unlike most US cities it is not on a river. Rather it is at the end of a mountain chain, on a height of land. No wonder there is no water. Move, move I say. They do not hear me. Well at least it is not New Orleans, below sea lavel.

    • It is surprising to me that a place with nearly 50 inches of annual rainfall could even be at risk for having a drought.

      • Check out the size of the basin for the Chattahoochee River north of Atlanta – its pretty small relative to what you might see.

      • Dave Springer

        Places with 50 inches of annual rain and a 12-month growing season find a way to use 50 inches of annual rain, no problemo. A few years in a row with a 20″ deficit and they’re f*cked.

    • It is on the Chattahoochee River. Its not a particularly large river – but a river nonetheless.

    • Not enough water in Atlanta? You can thank in part Jimmie “Let’s solve the energy crisis by wearing cardigans” Carter.


      “When Jimmy Carter became governor, he successfully fought the dam project at Sprewell Bluff, a very scenic spot on the Flint. As president, Carter began a process that eventually resulted in the de-authorization of the three [dam] projects on the Flint in the Water Resources Development Act of 1986.”

      No additional electric power. No flood control. And no reservoir to alleviate periods of drought. A perfect example of progressive green policy.

  13. I vote for red shift in a South American lake.


    Megadroughts and megafloods such as we have not seen in the instrumental record. It is as well a mistake to think of ENSO, PDO and AMO and indeed other indices as distinct and separate mechanisms. They seem more part of a global and dynamically complex system.

    Decadal regimes have been known about in Australia since the 1980’s when Erskine and Warner (1988) noticed morphological changes in rivers after the late 70’s ‘Great Pacific Climate Shift’.


    • David L. Hagen

      Since CSIRO got their drought predictions backwards, I remain skeptical on the usefulness of any drought predictions from GCMS until they are validated against historic data.e.g., David Stockwell observes:

      It is well known that despite persistent attempts and claims in the press, general circulation models are virtually worthless at projecting changes in regional rainfall, the IPCC says so, and the Australian Academy of Science agrees. The most basic statistical tests in the paper demonstrate this: the simulated drought trends are statistically inconsistent with the trend of the observations, a simple mean value shows more skill that any of the models, and drought frequency has dropped below the 95%CL of the simulations

      See Stockwell’s “Drought Oops” observations on a CSIRO paper acknowledging GW did not cause a drought in SE Queensland. For formal details see:

      David R.B. Stockwell, Energy & Environment, 21:5, 425-436, 2010

      the simulations indicate that the measure of hydrological drought increased significantly last century, while the observations indicate a significant decrease. The main conclusion and purpose of the paper is to provide a case study showing the need for more rigorous and explicit validation of climate models if they are to advise government policy.

      Increases/decreases in biomass productivity etc with rainfall/drought would appear to be much more believable.

      • Dave Springer

        Where I live the water level of the reservoir is more or less repeating the “drought of record” which happened from 1950-1960. It appears to be following a 60 year cycle. Now where have seen one of those before. Oh yeah, that’s right. The Atlantic Multi-Decadal Oscillation. What a surprise. Not.

      • David L. Hagen

        ~60 years – now where have I heard that frequency?
        cf Pacific Decadal Oscillation (PDO) & Don Easterbrook
        e.g., Geological evidence of recurring climatic cycles
        or at WUWT

      • An interesting statistical test involving changing trends and ocean oscillations.


      • David L. Hagen

        Quirk summarizes:

        One of the most useful analytical techniques where there is timing information is the use of coincidence to separate signal from noise. . . .
        This analysis has identified a series of coincident changes that are unlikely to be a random coincidence of events since it is possible to understand that the Pacific and Atlantic Decadal Oscillations cause breaks in global temperatures, a rebalancing of ocean and atmosphere exchanges of CO2, consequent changes in humidity and indirectly changes in the annual increases of atmospheric methane.

  14. In 1988, in the hothouse Congressional hearing, James Hansen claimed regional skill for his climate model, and blamed that season’s heat in the Southeast on Anthropogenic Global Warming. The models still don’t have regional skill.

    But we still have James Hansen.

  15. Head North a bit; that is, to the Niagara Escarpment and then onto the Bruce Peninsula. Red and white cedar tell a story of variable drought over the past 1400 years.


    Here tree rings infer regional precipitation, including the Medieval Warming Period and Little Ice Age. So, tree rings are good for something; that is, as a gauge of local precipitation. Dry warm times, thin tree rings.

    Tree rings make terrible thermometers. What are Climate Scientists thinking? And all this information occurring in modeler Gavin Schmitz’s back yard. Talk about turning a blind eye.

  16. Hasn’t there been farming in that area since like 1600? Surely there is a record of droughts. It seems it would be much easier to validate tree rings to drought than average variations of a few degrees, as rainfall is cumulative over the year, while average year to year variations are far less than day to night. Also a few degrees average change doesn’t excite a farmer nearly as much as 100 days without rain (I’m on a farm, so I’m sure of that!).

    I would be very curious how they handle picking trees for signals for drought. Do they throw out the majority of them if they don’t fit? Do they archive all of them? Would they be willing to do a guest post on the tree ring methodologies that seem so controversial?

  17. Obviously, nothing can be done unless the federal government can be neutered. What can Georgia do with, for example, Senators from Boston controlling their futures.

    Margaret Thatcher said, “Socialist governments traditionally do make a financial mess. They always run out of other people’s money. It’s quite a characteristic of them.” The fall of the blue states will move especially quickly if the federal hegemony over human activities is supplanted by a greater state autonomy. This could happen if the secular, socialist Big Government’s use of the Commerce Clause to diminish personal liberty becomes a dead man walking and if the peoples’ right to keep what they earn is reaffirmed.


  18. The Skeptical Warmist (aka R. Gates)

    Paleoclimate studies are essential tools of course in identifying past variability, but these are descriptive in nature, rather than identifying some sort of attribution or linkage to other climate drivers. IMO, a better approach is to combine paleoclimate studies with techniques such as Single Value Decomposition (SVD) as a statistical method to at least identify linkage to sources of moisture in any given region. Here’s a study that did it for areas of snow pack in the western U.S.:


    These kinds of SVD studies can be a first step to providing a more regional approach to climate models with the idea that once you can identify very specific sources of moisture for a region, you can then link climate changes that affect those source regions, and begin to create more regionally accurate models. Of course, you can never let go of the paleodata, as it can tell you what the underlying natural variability might be as a signal that would ride on top of any longer term changes.

    • A sub-equatorial region of the North Pacific Ocean is said to contribute to snow pack in Utah and Colorado. This sort of stuff has been done since Sir Gilbert Walker identified the link between sea level pressures at Tahiti and Darwin with the Indian monsoon.

      These links are followed with considerable interest around the world and provide insight into global hydrological patterns – http://ioc-goos-oopc.org/state_of_the_ocean/all/ – Most of these indices have demonstrated regional hydrological correlations and provide the best means of interrannual to decadal probabilistic forecasting available.

      If you look at the 11,000 ‘red shift’ ENSO link I posted above – it is difficult to impossible to distinguish change against such extreme variability. ENSO is of course the major determinant of global hydrological variability.

  19. steven mosher

    If forced to choose I would choose the paleo work. Then I would note
    that we are presently unprepared for a future that looks like the past.
    and woefully unprepared for a future that looks like the models.

    • What would be woeful is to assume 21st century climate looks anything like the pre-industrial climate. I thought we had dispelled that one by now, except for the most hardened types.

      • steven mosher

        “What would be woeful is to assume 21st century climate looks anything like the pre-industrial climate. I thought we had dispelled that one by now, except for the most hardened types.”

        Perhaps you missed my point. I said nothing about what the 21st century climate will look like. However, if the past 400 years had X number of droughts I think it would be foolish to plan for the next 400 years as if we were going to have fewer droughts. How much safety factor you want to put in on top of that is a very tough question. It’s not simply answered by either believing in the models or believing that history will roughly repeat itself. The point being that even if we get lucky and history only repeats itself we are still under prepared.

      • Yes, I referred to the 21st century only because of the article. It was aimed to make your point more relevant to these 21st century projections, but you may be disagreeing.

      • Heh, there is a huge range of pre-industrial climates and 21st Century climate is going to look just like one of those, somewhere. Sometime. Maybe even in the future. ::grin::

      • You may need to go back a few million years.

      • Or forward, to infinity, and beyond.

    • steven mosher | June 20, 2012 at 11:43 pm |

      This is the closest to my “E. All of the Above” approach.

      Remembering, I’m not conversant with the article’s authors, but will accept Dr. Curry’s word on their reputation, and that I’m not qualified to critique the work itself (nor do I have full information from the paleo work on which to audit it), etc., it looks like the models by not agreeing tell us nothing in our present knowledge allows us to predict droughts farther into the future than we can predict horse races.

      However, I would also disparage the paleo record as largely belonging to a previous climate state, one which may bear no resemblence to current or near future climate regimes. How would we compare factors affecting the US Southeast rainfall between years when the hurricane and typhoon seasons start and end a month sooner and later and in an area of ocean sixteen times as large? With an ice free (in summer) Arctic?

      This is the most expensive possible scenario: where no knowledge from the past or from models helps us at all. That is Uncertainty.

      • Cyclones, hurricanes, typhoons – a rose by any other name – form over open oceans in specific parts of the world when ocean water to 50m exceeds 26.5 degrees C. But as most warming was entirely natural the issues with bigger and better storms are almost entirely natural too.

        The authors considered drought and concluded that 20th century conditions were wetter than is historically true for the region. This seems pretty obvious from diverse strands of hydrological evidence.

        There are a number of ocean and atmospheric indices with established correlations with regional rainfall, these are followed very closely and provide the by far the best indications for seasonal to decadal forecasts. It is foolish to ignore these and concentrate instead on some chimerical conception of global warming.

    • Mosher,

      Let’s look at the reconstruction skill of this one and the recent Melvin/Briffa Climate Dynamics paper for SE UK.

    • The Skeptical Warmist (aka R. Gates)

      Well put.

  20. Dave Springer

    Dr. Curry, would you feel safer flying in an aircraft with a perfect safety record or taking the first flight in a new aircraft with no history but an assurance that, on paper, it appears to be safe?

    When you answer that you’ll have the answer to the question of which is the more useful data for water planning in Atlanta.

  21. If the word “denier” has been overused to the extent that it no longer conjures up images of Nazi atrocities, then I feel it should be applied to those who deny that current climate change is natural, just as all climate change preceding it has been. I suppose Dr. Bain would also apply the “denier” label to the late Dr. H. H. Lamb, whose encyclopedic works such as “Climatic History and the Future” have no place for catastrophic anthropogenic climate change. Dr. Lamb, founder of the Climatic Research Unit at the University of East Anglia, would be appalled at how deeply his lifelong pursuit of climate science and knowledge has fallen. If deniers we be, we are in good company.

  22. Willis Eschenbach

    Jim D | June 20, 2012 at 10:08 pm

    For example, extreme warmth in summer (three-sigma events) is already becoming ten times more common than in the 20th century (not models, but statistically).

    I hate this kind of claim. Which area are you talking about? The whole world? North Carolina?

    Which statistical period are the claimed “three-sigma events” based on? Did you adjust for autocorrelation?

    And which records did you use? HadCRUT? Local met service?

    Finally, in a time of general warming (e.g. the last three hundred years) you need to be careful and take special precautions when you are calculating statistical significance of extreme values over long time periods … was that done?

    This is science, not “let’s tell an anecdote”. You need to detail and substantiate your claims, anything else is just handwaving.


    PS—What does “becoming ten times more common” mean? Either it is ten times more common, or it isn’t …

    • It was Hansen’s paper on loaded dice. It was just on the statistics of climate, no modeling. He looked at the seasonal temperature distributions mapped globally (land) from which he defined 3-sigma tail events that had a probability of a few tenths of a percent, but are lately a couple of percent. This can be visualized with the area of 3-sigma anomalies growing. Texas in 2011 and Russia in 2010 show up. Interestingly the higher winter variability makes the change in 3-sigma area much harder to see for that season.

      • Willis Eschenbach

        Thanks, Jim. However, a search for “hansen ‘loaded dice’ ” brings up a host of things, but no paper. Do you have a link?


      • Wills, you can find it at http://www.columbia.edu/~jeh1/mailings/2012/20120105_PerceptionsAndDice.pdf and other places.

        “Climate dice”, describing the chance of unusually warm or cool seasons relative to climatology,
        have become progressively “loaded” in the past 30 years, coincident with rapid global warming.
        The distribution of seasonal mean temperature anomalies has shifted toward higher temperatures
        and the range of anomalies has increased. An important change is the emergence of a category
        of summertime extremely hot outliers, more than three standard deviations (σ) warmer than
        climatology. This hot extreme, which covered much less than 1% of Earth’s surface in the period
        of climatology, now typically covers about 10% of the land area. We conclude that extreme heat
        waves, such as that in Texas and Oklahoma in 2011 and Moscow in 2010, were “caused” by
        global warming, because their likelihood was negligible prior to the recent rapid global warming.
        We discuss practical implications of this substantial, growing climate change.

        Let us know what you think of it – it’ll be interesting to see if you spot the same flaws that I did

      • Willis Eschenbach

        Thanks, Peter317. Whoever told those guys that they could do statistics could be shot. The idea of comparing temperatures in 2010 to the 1951-1980 base period is a joke.

        To see how much of a joke, consider if they’d chosen to use the 1851-1880 base period instead. Because if you can choose 1951-1980 as your base period, surely you can choose 1851-1880 … and if you do, every single temperature would be a “three-sigma outlier”. Hansen would be funny if he wasn’t so dangerous.

        For those kinds of “three-sigma event” claims to have any meaning, the dataset has to be what statisticians call “stationary”. From here:

        Statistical stationarity: A stationary time series is one whose statistical properties such as mean, variance, autocorrelation, etc. are all constant over time.

        However, since the AGW folks like Hansen are always shouting about rising temperatures, it is obvious that the temperature record is not stationary, at least over the time period of interest.

        Jim D., a word of caution. Never, ever, ever believe what Hansen tells you. Run the numbers yourself. Of course, this is true of everyone, including myself, but if you quote Hansen, statistics say that there’s a 99.7% ± 0.3% chance you’ll end up looking very foolish.

        All the best,


      • Willis, the first line of the abstract says what they used as a base period, so that sets the scene for the paper. You can use colder base periods and find that Texas 2011 and Russia 2010 may have been 5-sigma events, but how does that help you? They become even less likely to have occurred by chance and more likely to be attributable to climate change, which is the gist of the paper. He is actually quite generous to use a base period after the warming has already started, which understates his message if anything, but on the other hand using a recent base period emphasizes how quickly the climate extremes are changing.

      • Willis Eschenbach

        Jim D | June 21, 2012 at 10:13 pm |

        Willis, the first line of the abstract says what they used as a base period, so that sets the scene for the paper. You can use colder base periods and find that Texas 2011 and Russia 2010 may have been 5-sigma events, but how does that help you?

        It helps you by pointing out the asinine stupidity of using Hansen’s kind of statistical analysis on a non-stationary dataset like the temperature … please, please get a statistics text and read up on stationary datasets before you make yourself look even more foolish, Jim. Hansen has made a newbie mistake. You are defending it.


      • Willis, he chose a second baseline and a detrended 1981-2010 period, to show that his results are robust to this choice. Your stationarity argument looks like some straw-grasping when you see the small effect of detrending compared to the interannual variability that dominates his distributions, as he says near the bottom of p3. The climate only has to be stationary relative to the size of interannual changes in the baseline period.

      • Willis Eschenbach

        Jim D | June 21, 2012 at 11:23 pm |

        Willis, he chose a second baseline and a detrended 1981-2010 period, to show that his results are robust to this choice.

        Neither you nor he have grasped the nettle of non-stationarity. For example, he says:

        The question then becomes, what is the most appropriate base period to use. We will argue that the appropriate base period is close to our initial choice, 1951-1980.

        If the choice of the base period affects the results as Hansen says, such that one base period is “appropriate” and another is not … then the dataset is not stationary. You still don’t seem to understand that in a non-stationary dataset, calculations of “three-sigma events” are meaningless.

        You don’t get to pick and choose your base period, Jim. If you can just pick a base period, then I pick -8080 to -8051 as the base period. After all, as Hansen says, “The most useful base period, we suggest, is one representative of the climate to which life on Earth is adapted.” Certainly that period, the Holocene, is representative.

        Of course, since the climate was a couple of degrees warmer then, we obviously are in a period of three sigma cold events … do you see why the calculations Hansen and you want to apply are meaningless in a non-stationary dataset?

        Again, I urge you to research the question of stationarity, and the effect of non-stationarity on statistical calculations. You and Hansen seem equally at sea regarding this crucial issue.


      • Willis, as I see it the fatal flaw in this paper is not even that he’s attempting to predict weather events from a distribution of average temperatures, it’s that he’s not even using temperature data for his distributions, but rather temperature anomaly data.

        As I said on another thread some time ago, it doesn’t take a genius to figure out that a one-degree increase in night-time temperatures in Nome or Nuuk doesn’t have the same effect as the same one-degree increase in daytime temperatures in Tripoli or Timbuktu – yet they will show up the same in the anomaly distribution.
        Temperature anomaly data are already an abstraction of the temperature data, so a distribution of the anomaly data really amounts to an abstraction of an abstraction – and, as such, really says nothing about anything.

        But I suppose you can get away with any statistical chicanery just as long as it happens to support the theory.

      • “You don’t get to pick and choose your base period, Jim. If you can just pick a base period, then I pick -8080 to -8051 as the base period.”

        Does radiant elements explain -70,000 to 69,970 period or -70,000 to -60,000 period.
        Or does the Bond albedo from a bunch ice on land areas really have much affect on global temperature.
        Or is the elevation of an ice cap have large effect upon temperatures?
        If snow is 20′ high as compared the a mile high is has same Bond albedo
        but does it have same effect on regional temperature.
        Whereas if blacken an ice cap [or all ice caps], I have little doubt this increases it’s rate melting, but such radical change on Bond albedo shouldn’t have much effect on global temperature.

        I get impression that Bond albedo of land or even ocean is pretty much ignored, whereas Bond albedo from clouds is the more important aspect.
        In this context why does matter what color [including snow white] all of Canada is in terms of global temperature?
        With snow caps covering a good portion of North America, we could assume there less cloud cover over North America. Or as with most places with ice caps there tends to be less snowing.
        Say, Minnesota gets about 2′ feet of rain per year- if that is snow/ice accumulation in 10,000 years you get 20,000′ of ice. So some some evaporates and flows, but mainly one expect less precipitation to explain why over 80,000 year one has less stacked up ice. So generally, less clouds.
        So less clouds, the lack of much significant of Bond albedo of the “ground”, the land area with has ice caps in terms total global area, is rather insignificant.
        So, if looking mostly radiant factors, why are ice ages 10 C cooler?

      • Willis, for you to claim that anyone choosing 1951-1980 as a climate base period is wrong indicates that you don’t believe 30-year climatologies even though they are used as a definition of climatology for many practical purposes. The claim of non-stationarity is bogus because the trends are far smaller than interannual variability that gives you the distributions. Has anyone ever claimed a 30-year climatology can’t be done for mid-century data because of non-stationarity? No, it is your ad hoc invention for this thread. You can calculate the trend, which is almost non-existent in that period, and the variance and find that the variance far exceeds the trend to prove it for yourself. What would non-stationarity even look like? It would be a trend line with noise on it. Does the 1951-1980 climate at any of the points look like that? You seem to expect it does, which is the situation where climate change dominates interannual signals. If that is true, it is indeed worse than we thought.

      • Willis Eschenbach

        I did find this from Hansen in 2000:

        Remarkable climate extremes have occurred recently: the Chicago heat wave of 1995, a run of 29 days of 100°F temperatures in Dallas in 1998, floods in the Midwest in 1993 and 1997 and in the Southeast in 1999. The high natural variability of climate prevents unique association of these events with global warming. But a quantitative index of temperature and moisture changes reveals that climate extremes are increasing at most places in the sense predicted for global warming. And we can predict with reasonable confidence that the record annual and decadal temperatures for the 48 contiguous United States, set in the 1930s, will soon be broken.

        But that’s just more handwaving … his citation style is as bad as your first attempt. He cites two things, a paper about forcings which says nothing about floods or heat waves, and a presentation he gave at some conference somewhere. Color me unimpressed.


        PS—Hansen is impressed by the obvious fact that in a time of increasing temperatures like the last 300 years or so, the most recent decade is very likely to be the warmest … can you say “expected outcome”? Because Hansen obviously can’t, he thinks it is a sign of the Apocalypse …

      • Beclouded vision,
        Cerebro-Optic Cortex.
        Man of simple faith.

  23. base research on real data and not so much on climate models. What a wonderful idea.

  24. There is almost always a flood somewhere and a lack of water somewhere else. We need to move the water from where there is more than enough to where there is less than enough.

    • Dave Springer


      My friends and family in southwestern New York state complain of cold & wet when I complain of hot & dry in south central Texas. It’s almost enough to one a believer in Newtonian weather – for every extreme weather event in one place there is an equal and opposite extreme weather event somewhere else. This kind of makes sense given the amount of energy the earth receives from the sun is constant so when there’s a dearth of weather-producing energy in one place there is a surplus somewhere else. Isn’t it grand how fundamental principles in physics can be observed in unexpected places if you just bother to look?

  25. Great post.
    It is only under the influence of AGW extremists that so-called climate models have become misidentified as important tools with which to plan the future..

  26. If the natural variability is far greater than the variability shown by the models, by preparing for the reconstructed variability you are by default preparing for the model outcomes.

  27. We have a ‘drought’ in the UK despite it endlessly raining since late March. Today again we have much of the south of England expecting 1 inch of rain. Our reservoirs are full, our rivers are flooding into peoples homes and we are not allowed to use hose pipes. We don’t need to, the plants are more in danger of drowning than shirivelling. You couldn’t make it up. Once people can start to believe what they are told instead of disbelieing the endless scare stories of drought the more we will take notice and preserve resources, when required.

    • Dave Springer

      Water use restrictions are generally made by underground aquifer and above ground reservoir levels. Perhaps the recent rainfall has not yet been sufficient to recharge either of those to levels not considered worrisome.

      That’s how it works where I live. We had a wetter than average spring after two consecutive years of drought but it hasn’t even come close to recharging our reservoirs or aquifers.

    • DavidCH,
      Your AGW extremists have dumbed down the definition of “drought” so that you can literally be experiencing flood while they ‘adjust’ your economy to deal with the terrible drought their models have predicted.
      Who are you going to believe? Your lying eyes or the solemn revelations of the climatocracy?

      • Their rivers and reservoirs are above normal after intense rainfall since April. They say their groundwater storage basins are still depleted.

        It does sound like restrictions are being lifted.

      • We were predicted to have a lovely summer, today 13C and guess what it’s flooding weather conditions again, No signs of end in the forecasts. Publication bias in the scientific press, exaggerated by media reporting, has created a feeding ground for average scientists to use alarmism for grazing purposes. Sure the aquifers remain low and some areas use these for up to 65% of their water supply (so they claim), I wonder how one particular water authority indicates their 4 (area) aquifer levels have stayed level or even diminished since the April downpours began and continue to this day. There’s only so much Trees can drink surely? My Tomatoes and leaves are well satiated, indeed I’ve protected them from drowning.

      • From the North of England (Lancashire/Yorkshire) to the very south (Isle of Wight) the same story now for 3 months.

    • Here’s the latest, doesn’t seem a week goes by without flooding causing misery. Yet drought prevails.

  28. It seems to me that the most important characteristic of forecasts that decision makers should take into consideration, is the past record of the forecaster in making future forecasts. In other words, the track record of whoever is making the forecast.

    The track record for the climate models has, I suggest, been somewhere between non-existent and abysmal. Most of the forecasts as so far in the future, that they can never been checked. Whether anything else is any better is, I suggest, something that needs good statictics in order to make any judgement.

    Again, I come back to a point I keep on trying to make here. If anyone wants to be known as a good forecaster, then they need to make forecasts on a short time period, so that their forecasts can be readily checked. Then, if anyone happens to make a lot of accurate forecasts, maybe their methodology is worthwhile looking at in detail. I tried to make this point with the recent ARCUS forecast of minimum ice extent in the Arctic in 2012, but my effort was sidetracked with a discussion of other aspects of what is being done.

  29. Joe's World


    There is a distinct pattern of water vapor movement. I see this all the time living on the Southeast corner of the great lakes. Many weather systems threaten but we are almost always bone dry.
    Many storms come barreling in from the west and hit the great lakes and are diverted north or dissipates over the water.
    Any other areas, north, south, east or west get much of the weather but ALWAYS, the southeast corner is usually spared.

    • Joe's World

      You know that could be because of or planets rotation and velocity differences…
      Now why did I not think of that? Hmmmmm.

    • Dave Springer

      I grew up on the southeast corner of the Great Lakes. New York State, Southern Tier, on the Allegheny river to be more precise. I spend a summer there once in a while and spent a winter there in 2010. The only water vapor movement I know of that you could possibly be referring to is “lake effect snow”. I was about 60 miles from the closest shore (roughly equidistant from Erie and Ontario) and that’s on the borderline of where lake effect snow ends. That’s exceedingly regional and given the Great Lakes are the largest body of freshwater in the world a very unique situation. So I’m not sure that lake effect snow is relevant to global climate study.

      • Dave Springer

        P.S. in 55 years I’ve never seen what I’d call “bone dry” on the southeast corner of the Great Lakes. I lived in Southern California and South Central Texas for about 20 years each and in both those places you learn what “bone dry” really means where you can go weeks and sometimes months without a drop of rain. The southern tier of New York State is a rainforest in comparison with some 45 inches of annual rainfall and another 10 inches of rainfall equivalent in snowfall.

  30. Trying to look at this from the decisioin maker’s point of view, one of the ways that the proponents and opponents of CAGW differ, is whether adding CO2 to the atmosphere has CHANGED the climate. The proponents argue that significant change has occurred; the opponents say that while, in theory, a change has occurred, in practice to amount of change is negligible and can be ignored.

    The decisoin maker then needs to assess whether change has, in fact, occurred. If it has not, then the past record could be a guide as to what will happen in the future.

    This is why I keep coming back to the fact that in temperature records for the 20th and 21st centuries, there is no discernable CO2 signal in ANY temperature/time graph, that can be proven to have been caused by adding CO2 to the atmopshere. Zero, nada, zilch.

  31. Dave Springer

    Jim Cripwell | June 21, 2012 at 9:15 am | Reply

    “Trying to look at this from the decisioin maker’s point of view, one of the ways that the proponents and opponents of CAGW differ, is whether adding CO2 to the atmosphere has CHANGED the climate.”

    Yabbut a 400-year rainfall history by definition includes any changes to date. According to climate boffins the change has been rapid and dramatic in the past 60 years. If this is true it should be evident in the past 60 years of the history and it will stand out and thus influence the water recommendations.

    I happen to live on the shore of a large reservoir at the approximate latitude of Atlanta and am keenly aware of the history of lake level fluctuations as they have a more direct impact on me given I have boat launch ramps, floating docks, and other level-sensitive concerns. The “drought of record” which the Lower Colorado River Authority uses as a benchmark in water conservation policy happened in the 1950’s where there was a ten year period with substantial rainfall deficits in a majority of those years without offsetting surpluses that could be captured and held through the deficit years. We are about 4 years into a repeat of the “drought of record” with one single annual deficit that was more extreme than any year in the drought of record. For the first time in 50 years downstream rice growers had their water supply cut off. Rice growers account for better than half the water use from the reservoir and they use the water for nothing more than to kill weeds by flooding the fields prior to planting. They have two crop cycles per year. In the ten years prior to the recent four years of drought we had three 100-year floods (according to projections made in 1940 when the dam was completed) which prompted the Army Corps of Engineers to once again raise the level of the 100-year flood plain a few years ago.

    A steady history of the Army Corps of Engineers raising the level of the 100-year flood plain from 690’MSL to 722’MSL is not a history of increasing drought but one of increasing floods. Yet here we are in what appears to be a repeat of 1950. Perhaps when this is over the ACoE will lower the 100-year flood plain. In any case it’s another bit of evidence that the Atlantic Multi Decadal Oscillation, which has a period of 60 years, is more predictive of climate change than anthropogenic CO2 emission.

    • Dave Springer, you write “According to climate boffins the change has been rapid and dramatic in the past 60 years. If this is true it should be evident in the past 60 years of the history and it will stand out and thus influence the water recommendations.”

      Unfortunately you omit to say WHY the climate boffins say anything. My impression is that they are giving an OPINION. I only believe in hard measured DATA. If you can show me where the climate boffins have provided any valid data to support what they say, then maybe I might take some notice.

      As I say, so far as I can see, the climate boffins have no basis whatsoever to claim that the last 60 years is any different from what has happened in the past. If you have a reference which bears on this issue, I would be very grateful. But, please let us have it based on data, not opinion, or the output of non-validated models.

  32. The drought study is based on solid forecasting principles –> ‘the future will be pretty much the same as the past’ as the default prediction. Given no known major disruption to a system, and for long term earth climate in general, I do not believe there has been any, it is almost always your best bet. Long term climate comparisons (hundreds of years, thousands of years) give us insight into the conditions that can be expected and their relative frequency.

    This means that the low-country states — Georgia, and the eastern Carolinas and parts of Virginia — will see periodic two and three year dry spells, sometimes longer. Knowing this can help them increase the number and capacity of drinking water reservoirs and locate heavy water-consuming industries correctly.

    Had these principles been applied to, say, Arctic Sea Ice extent, no one would be surprised by the current spell of minimal sea ice — a condition that appears occasionally in the historical record.

    The catastrophist claim of ‘unprecedented’ weather/climate usually means that no one has looked seriously at the past, or has taken only a very short-sighted look.

  33. Interesting that this paper uses tree rings to infer rainfall rather than temperature
    We know from the Hockey Stick that tree rings may not be best for temperature. Tree rings do make sense for rainfall.

  34. There is almost always a surplus of water somewhere and a shortage somewhere else. We need to build canals and pipelines to move the water.

    • Herman, you write “We need to build canals and pipelines to move the water.”

      Have you worked out the cost of moving water any sort of distance, both in monetary terms, and the amount of energy it takes?

      • Jim,

        You apparently aren’t from California, where nearly 100% of the water for one of the largest extended metropolitan population centers in the entire country (Ventura south to the Mexican border, including all of Los Angeles County, Riverside Country, Orange County, San Diego) comes from vast distances away ….the Colorado River, the Sierra Mountains, etc.

        Ask Anthony, or even Peter Gleick.

      • kip, Let me guess, what you are talking about is water being moved by gravity. The Romans used this system centuries ago. The problem with costs is when you need to moved water uphill. That is when it becomes expensive. Which is what I interpreted Herman to be talking about. Moving water to places which are under drought conditions, from places which are suffereing from floods.

      • Jim,
        Who knows, except for Herman, what Herman thinks. The low-country of Georgia and the Carolinas is downhill from almost everywhere. The drought areas are in the flat country inland from the coast, but not in the tail-end of the Appalachians. See http://droughtmonitor.unl.edu/DM_southeast.htm

        In any case, just moving water around really doesn’t do it. Farmers need rain or cheap irrigation water. Cities need drinking water. These SE US drought areas need more reservoirs and delivery systems to overcome the tendency to periodic multi-year droughts, as shown in this study.

        BTW, NY City has huge reservoirs in the Catskills and Berkshires and pipes it all down to greater NY.

    • Jim and Herman

      As Kip noted out here in CA most the water for southern ca in conveyed there from various spots around the state. The California Department of Water Resources http://wwwdwr.water.ca.gov/ manages the movement of water. To get a feel for how much water you might find their
      “Climate Action Plan

      Phase 1: Greenhouse Gas Emissions Reduction Plan” of interest


      I pulled some data out of the plan to give you a feel for how much water gets moved around the state, how much energy it takes to accomplish the task and what the CO2 impact is-
      Table 4. Water conveyed, energy purchased, and emissions 1988-2009 Examples

      Year Water (MAF) Load Gkw MtCo2 (million)

      2005 4733 8308 3.20

      2009 2019 5438 2.08

      Last time I check 20% of the states electrical energy was used to move and treat water.

  35. The entire science of global warming alarmism is built upon chimera. Let us assume an increase in the concentration of atmospheric CO2 as an avoidable consequence of modernity.

    Let’s work with 300 going to 400 ppm because of industrialization. A 33% increase. Sounds like a big bump. Right?

    But how about going from 0.03 to 0.04%? Does that extra 0.01% of CO2 in the air really make any difference?

    If you don’t know it is only because this is the sort of question for which AGW True Believers really don’t want an answer. Government science authoritarians want you to keep the faith and for that, ignorance is bliss.

    The witchdoctors of AGW do not want to put this question to the test either. ‘Forget the chemistry,’ they will say and plead that you listen instead to superstitious analogies — e.g., ‘CO2 is a deadly poison so any increase no matter how small poses life-threatening consequences.’

  36. OT
    Interesting paper/study on the melting of Antarctic ice. Interesting how the models disagreed with satellite measurements, and now the new measurements agree with the satellites rather than the models. Wondering how/why models are kept when they don’t agree with actual measurements, what are they supposed to be modelling?
    direct link to paper:

    • Nice link, “The team’s results show that water temperatures are far lower than computer models predicted, which means that the Fimbul Ice Shelf is melting at a slower rate. Perhaps indicating that the shelf is neither losing nor gaining mass at the moment because ice buildup from snowfall has kept up with the rate of mass loss, Hattermann said.”

      I am shocked! How could the Antarctic waters possibly be lower than modeled? -1.9C? I thought the Antarctic was warming at the unprecedented rate of 0.1C per decade just like GISS says? It is almost like something is amiss :)

  37. ‘Infinity and beyond.’ I think I hear the laughter of the gods.

  38. Judith,

    Please note that there is work that has been submitted that shows that the variance in control and forced model runs is comparable with that of reconstructed PDSI, over the last millennium (at least for the American Southwest, I’m not sure about the SE, though the proxy reconstructions of PDSI make a variance comparison a bit difficult). Jason Smerdon has given a lecture on this recently to my university. But your ‘choice’ is a false dichotomy…it is useful to blend models and paleo-reconstructions. This is also a useful paper

  39. Willis Eschenbach

    Jim D | June 22, 2012 at 9:13 pm |

    Willis, for you to claim that anyone choosing 1951-1980 as a climate base period is wrong indicates that you don’t believe 30-year climatologies even though they are used as a definition of climatology for many practical purposes.

    Say what? You don’t have a clue what I believe, any more than I know what you believe, so don’t make yourself look foolish by guessing.

    30-year base periods have many uses, not to mention many misuses. Note that many organizations these days are using the 1981-2010 base period, like say the UAH and RSS satellite folks. Or your could see, for example, the statement from NOAA/NCDC regarding their use of the new 1981-2010 base period for their normals … perhaps you could tell the class why they have updated them.

    The WMO recognizes the problem of statistical stationarity that you and Hansen seem oblivious to, saying (emphasis mine)

    Standard Normals use a 30 year base period and are updated every 30 years. This works well in a stationary climate. But when the climate is changing, Normals produced from data observed as much as 50 to 60 years ago are not as useful as more recent Normals would be. Therefore, OPACE I co-chair William Wright drafted a discussion paper on changing the definition of the standard climate Normals. It proposes a dual Normals system with a relatively-stable 30 year base period for climate monitoring applications, but also providing for 10-year updates of the 30 year Normals for other applications (e.g., 1981-2010).

    So the WMO recommends updating the base period every 10 years for anything but “climate monitoring”, and many organizations including those I mentioned above are doing that. However, even the WMO “stationary climate” base period at present is 1961-1990, not 1951-1980.

    I know of no organization that is still using the antiquated 1951-1980 base period for their work of any kind except Hansen and GISS … perhaps you could explain that as well.


    • OK, maybe you agree that using a base is then a good way to show how climate is changing. What was extremely rare in 1951-1980 is now more common. That was the message he was trying to convey, no more than that, and it can be quantified and visualized using the distribution curves and seeing how they shift. Events like Texas 2011 and Russia 2010 could not have occurred with any likelihood in 1951-1980. Neat, isn’t it?

      • Willis Eschenbach

        Jim D | June 23, 2012 at 1:08 am | Reply

        … What was extremely rare in 1951-1980 is now more common.

        Well, yes, Jim, it’s called a “warming climate”. You see, when the climate is warming, as it generally has been for the last three centuries or so, you tend to get warmer temperatures. Neat, isn’t it?

        For some unknown reason, you seem to think this is hugely significant, when in fact it just means that the climate is warming, as it generally has been for the last three centuries or so …

        The question has never been whether the climate is warming. Pretty much everyone agrees that it generally has been warming, in fits and starts, for the last three centuries or so.

        The question is, how much of that is due to human actions? You and Hansen seem to think that the fact it is warming means humans must be to blame.

        Finally, in a warming climate, you cannot use a long-ago baseline to claim that what Hansen is calling three-sigma outliers prove that humans are to blame. That doesn’t even pass the laugh test, and it exposes both Hansen and yourself as statistical newbies.


        PS—I must have missed your explanation of why Hansen and his organization are the only ones on the planet still using the out-of-date 1951-1980 baseline … coincidence? I don’t think so, but I await your thoughts on the question.