Trees show no rainfall pattern in last century

I’ve always said that trees are a better proxy for rainfall than temperature. Just looking at how trees cluster around water sources can tell you this. From the Hockeyschtick:

New paper shows no increase in precipitation over past 105 years, counter to global warming theory

One of the central tenets of global warming theory is that warming of the atmosphere results in increased water vapor and thus precipitation, leading to alarmist predictions of increased flooding. A paper published online [Wednesday] in the Journal of Geophysical Research counters this notion, showing that winter precipitation of the central Pacific coast has not increased over the past 105 years. Rather, a cyclical pattern of unknown etiology is found, which clearly shows no correlation to CO2 levels whatsoever.

Red horizontal line added to show zero anomaly level

Is energetic decadal variability a stable feature of the central Pacific Coast’s winter climate?

The central Pacific Coast of the United States is one of the few regions in North America where precipitation exhibited a high proportion of variance at decadal time scales (10 to 20 years) during the last century. We use a network of tree ring-width records to estimate the behavior of the observed decadal pattern in regional winter precipitation during the last three and a half centuries. The pattern was most vigorous during the mid and late 20th century. Between A.D. 1650 and 1930, proxy estimates show a limited number of events separated by longer intervals of relatively low variance. The multicentennial perspective offered by tree rings indicates the energetic decadal pattern in winter precipitation is a relatively recent feature. Until a physical mechanism can be identified that explains the presence of this decadal rhythm, as well as its inconsistency during the period of record, we cannot rule out the possibility that this behavior may cease as abruptly as it began.

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60 thoughts on “Trees show no rainfall pattern in last century

  1. From the source article at Geophysical Research Letters:

    “Key Points
    •Decadal variability over land is often attributed to decadal processes
    •Decadal variability along the central Pacific Coast was muted prior to 1900
    •The observed decadal pattern should not be used to predict regional climate”

    I like point number three here, but doesn’t that kinda go against what a lot of alarmist are doing?

  2. How long does it take for the Pacific to slosh from one side to the other – a decade? PDO?

  3. The cyclic variation in California’s Long term Rainfalls seem to be under the same influence as the tide at San Francisco. Based on 9 year averages. The tide record was detrended by .006 feet per year.

  4. After Briffa gets through with his analysis of the data, that graph will look like the proverbial hockey stick.

  5. “global warming theory” “winter precipitation of the central Pacific coast”

    “Red horizontal line added to show zero anomaly level” – well, if you “added a horizontal line” what did you expect the slope to be? What is the calculated trend?

  6. Wayne Delbeke says:
    June 17, 2011 at 9:19 am
    How long does it take for the Pacific to slosh from one side to the other – a decade? PDO?

    That was my first thought too, but it doesn’t explain why its a recent phenomenon.
    Hard to say without access to the paper (and I am not going to pay $25 for a copy).
    Personally, I suspect it has a lot to do with forestry practices. Older records will come from old growth trees. More modern ones probably don’t since old growth is protected, so we are probably looking at younger trees for the modern samples, which are possibly more susceptible to rainfall variations. Quite possibly slightly different types to tree too.

  7. Quick question – since the paper says ” showing that winter precipitation of the central Pacific coast has not increased over the past 105 years.” but climate is global is this really much evidence of anything pro/con?

  8. The warmista will say that while there apparently no warming in the Central Pacific Coast, the rest of the planet is boiling. I hope they will extend their work to other “regions” and eventually as global as possible.

  9. Have we run this paper by Chris for certification for publication yet?
    I don’t think he’ll approve, because the consensus believes that tree rings are good temperature proxies.

    Coincidentally, his buddy Dr. Louis Uccellini ( http://www.meteor.wisc.edu/ ) is president-elect of the AMS???? How convenient! We can now get some direct answers to the questions posed in a previous post!!

    http://www.ncep.noaa.gov/director/profile/

    I thought his talk in Israel was a bit interesting…starting at 6:30…and especially his comments about data quality at about 30:00…..

    More of his views:
    Climate Change –
    “Uccellini noted the hypothesis that a warming atmosphere will allow it to hold more moisture resulting in storms producing heavier precepitation. He discussed extreme winter weather events since 1993 that have produced some of the largest snowfall amounts recorded since the 1880s. He noted that although the trend toward heavier snowfall may suggest an influence of global warming, the sample size is too small to draw any conclusions. Another aspect of the climate-weather linkage is the role that El Nino and La Nina based circulation patterns can play on the evolution of the major cyclones which affect the U.S. The evolution and predictability of the major storms in 2010 (El Nino year) and 2011 (La Nina year) were discussed in terms of the contrast in predictability of the storms which occurred in these two winter seasons. In response to a question about reports by popular news outlets that other severe-weather events are occurring more often, he responded that the sample sizes are too small to draw any such conclusions.”

    http://www.rnrf.org/publications.html

    Sample sizes are too small to draw any conclusions?? I’ll remember you said that.

  10. The abstract has this as part of the summary – “The observed decadal pattern should not be used to predict regional climate”.

    Anyone here help me understand that caveat?

  11. I’m not a climate scientist. But, I find this a very frustrating graphic (precipitation anomolies). Where is the FFT? Are cyclical pattern judgements really made by time domain analysis? If they’re using tree rings why do they only go back 105 years?

  12. Trees are showing rainfall patterns. But the overall pattern is that rainfall has been normal. Maybe “normal” is not a pattern.

  13. Want tree ring proxies correlated with temperature? No problem.

    Want tree ring proxies correlated with CO2? No problem.

    Tree rings are a cherry-picker’s delight. About the only thing they can measure with any accuracy is past precipitation.

  14. Well, it’s not sunspots. A quick superposition of graphs in PhotoShop shows no clear correlation.

    I’d go along with PJP’s idea of tree-planting cycles. The change from steady to cycles happens at the same time as the New Deal reforestation program, which broke the old habit of clear-cutting without replanting.

  15. One of the central tenets of global warming theory is that warming of the atmosphere results in increased water vapor and thus precipitation,

    Warmer temperatures will increase absolute humidity, but there is no particular reason that I can see why relative humidity or precipitation would go one way or the other.

  16. “Moderate Republican says:
    June 17, 2011 at 9:44 am
    Quick question – since the paper says ” showing that winter precipitation of the central Pacific coast has not increased over the past 105 years.” but climate is global is this really much evidence of anything pro/con?”

    Probably not much evidence of anything till the decadal signal and other significant factors can be quantified.

    P.S. MR… If the trend exactly matched the warming slope from 1958 to say 1990, would it prove anything?

  17. Philip Peake (aka PJP) says:
    June 17, 2011 at 9:41 am
    ………
    Hard to say without access to the paper (and I am not going to pay $25 for a copy).
    Personally, I suspect it has a lot to do with forestry practices. Older records will come from old growth trees. More modern ones probably don’t since old growth is protected, so we are probably looking at younger trees for the modern samples, which are possibly more susceptible to rainfall variations.

    I suspect old growth trees were used for all the records, because (IMO) it’s allowable to take drill-core samples from them for scientific studies. Without doing this the results would be too ‘iffy” to be published–i.e., non-robust.

  18. As you must know Anthony, precipitation patterns vary from region to region. Dr Davis Sauchyn has documented this fact in Western Canada using tree rings as a proxy. His research reveals a pattern of wet a dry periods, which should give us all pause, because some of the droughts are over 40 years in the past 300 years . This natural situation is now being exacerbated by climate change which is being drastically affected by both winter and summer weather on the Prairies.

  19. Except the treemometer people would not dispute this. They point only to tree line mountain/polar trees as treemometers. The idea that tree line tree rings might be more responsive to temps than moisture pre-dates the global warming gravy train science so it has a clean provenance. But I have never found it well-explained in the past, only that it was a sincere pre-global warming scam conjecture. Briffa’s “secret” work and others’ work now have debunked the conjecture probably, but the old idea of tree line treemometers still is worth millions to Team Dendro, and Billions to Team Big Finance. Q: Why would the Global Warming financial interests and Governmental pawns give money to dendrochronologists if the dendros could not produce stats and c harts that look scarier than actual thermometer readings? A: There is no such reason.

    It’s about the money, clouded with quasi-religious belief and touchy senses of honor.

  20. Hugh Pepper said:

    “This natural situation is now being exacerbated by climate change which is being drastically affected by both winter and summer weather on the Prairies.”
    Hugh I have seen numbers saying there has been no ‘drastic’ changes in the US over the last ~100 years. Can you link evidence to the contrary?
    Jim, too.

  21. Um… Hugh? I live in Western Canada, on the prairies. There is nothing unusual going on here.

    What are you talking about?

  22. Couple of observations:

    1. We have seen 11 year variations of water volume in large South American rivers, synchonous with solar cycles (remember them?). the last 50 years or so in the graph look like they could be correlated — perhaps with some lag — with solar cycles, they seem to be about 11 years.

    2. Regarding this statement: “Between A.D. 1650 and 1930, proxy estimates show a limited number of events separated by longer intervals of relatively low variance.” — studies show that last century was actully the wettest in CA in the last millenium, not just from 1650. Suppose that increasing warmth actually is responsible, in CA, for more average annual rainfall. Considering what a real drought does to CA, isn’t more precipitation a good thing for CA?

    Just saying….

  23. The alkali lakebeds of eastern Oregon fill and go dry on a decadal time scale, so this is probably not an artifact of using trees as proxies. I cannot afford to penetrate a paywall every time I see something interesting, but I wonder if the data from the lakebeds can be reconciled with the trees.

  24. Hugh Pepper said:
    “This natural situation is now being exacerbated by climate change which is being drastically affected by both winter and summer weather on the Prairies.”

    Please refer to my post above with the statements of AMS President-elect Dr. Louis Uccellini. I believe what he holds is that the “sample size” is too small to make that kind of assertion.

  25. Hmmm. Are they telling me that there is no historical rain gauge data from the Central Pacific Coast to compare with the tree ring data? If there is, how do the two compare?

    I sense an opportunity here to apply cutting edge climate science a. Get the rain gauge data, throw away the corresponding tree ring data. (Maybe we’ll have to invent a new term since there doesn’t seem to be any decline to hide. [why not BTW?]). Add in the rain gauge data (the Nature trick). Apply Principle Component Analysis. With any luck at all, we’ll get the much sought prize — a hockey stick. Or maybe an inverted hockey stick. If the Nature trick doesn’t work, maybe we can try appending a different data set … until we get the answer we want. And we know that’s science because climate experts say it is.

  26. Nothing in this regional study refutes “global warming theory.”
    Nothing supports it either. I suppose you could call it almost-global or we-think-it-might-be-global warming.

  27. Hugh Pepper
    I live in Alberta and am wondering what in the heck are you talking about as well? You sure you read this article? And understood its concepts?

  28. Moderate Republican says:
    June 17, 2011 at 10:28 am
    _____________________________

    Do you have a science background? Are you trying to develop a strategy for a political campaign? Depending on what you say, it might be worthwhile to figure out how to connect offline. Can you give me at least the state you are from?

  29. “Until a physical mechanism can be identified that explains the presence of this decadal rhythm, as well as its inconsistency during the period of record, we cannot rule out the possibility that this behavior may cease as abruptly as it began.”

    Oh My God, genuine physical scientists. Note the intelligent humility. I hope they send their work to Briffa. This is what he should have done before the Crew ever got to the matter of “hiding the decline.”

  30. Moderate Republican says:
    June 17, 2011 at 9:44 am
    “Quick question – since the paper says ” showing that winter precipitation of the central Pacific coast has not increased over the past 105 years.” but climate is global is this really much evidence of anything pro/con?”

    May I declare this Troll a free-fire zone?

  31. hardly surprising there is no warming signal in these tree rings, since there is no warming in the east pacific basin either!

  32. Moderate Republican says:
    June 17, 2011 at 10:28 am
    The abstract has this as part of the summary – “The observed decadal pattern should not be used to predict regional climate”.

    “Anyone here help me understand that caveat?”

    In the part that Anthony quoted, the authors say:

    “Until a physical mechanism can be identified that explains the presence of this decadal rhythm, as well as its inconsistency during the period of record, we cannot rule out the possibility that this behavior may cease as abruptly as it began.”

    No physical mechanism means no physical hypotheses means no prediction. Just search WUWT on my name and you will find an encyclopedia on this matter. What they exhibit here is the natural humility of the genuine scientist. Briffa and the Crew should have made the same qualifications in huge print at the beginning of each of their articles. This event might very well mark the beginning of genuine paleoclimatology. Good. I am sick of propagandoclimatology.

  33. Running the numbers for a specific locale in that paper prior to 1880 gives an entirly different look to the tea leaves.

    Precipitation records prior to 1880 are found in the companies that ran the hydraulic mines.
    In some places you can get back to the late 1850’s, but the information that used to be freely available in the CA state library system is now locked up at ‘centers of higher learning’.
    Some folks don’t want that data to be seen anymore.

  34. Well obviously some areas have had “extreme” drought and some areas have had “extreme” wet weather…it just cancels out overall, but everybody knows “it’s worse than we thought.”

  35. AGW models predict a global increase in precipitation. There is no particular expectation of increases or decreases at specific locations/regions, on which models vary widely. Additionally, the reason for a global increase in precipitation is because the amount of evaporation increases in said models, not because of more water vapor. Evaporation must equal precipitation globally for reasons independent of AGW. But it is worth noting that, if anything, models severely underestimate the change in precipitation with warming:

    http://www.remss.com/papers/wentz_science_2007_paper+som.pdf

  36. Henry says: June 17, 2011 at 9:40 am
    “Red horizontal line added to show zero anomaly level” – well, if you “added a horizontal line” what did you expect the slope to be? What is the calculated trend?”

    The line is not the slope of the trend! You eyeball the ups and down and see that the trend is zero!

  37. pat says:
    June 17, 2011 at 9:28 am

    “After Briffa gets through with his analysis of the data, that graph will look like the proverbial hockey stick.”

    Unfortunately true.

  38. A real scientists say “we don’t know what causes ……., so let’s try and find out”

    A climate scientist says “we don’t know what causes…….. so it must be CO2″

    A real scientist ACCEPTS he doesn’t know everything…

    A religion INVENTS something to fill in the gaps.

  39. Andy G55 says @ June 17, 2011 at 8:20 pm “A climate scientist says “we don’t know what causes…….. so it must be CO2″

    Wow – that sure sounds pretty bad and I am thinking that it would be powerful to provide the citations where CO2 acting along is being called out as the sole cause of the climate change that is being identified. I’d have to think that citations that show that CO2 is the only forcer acting by itself would be a huge issue for climate science, no?

  40. The paper’s abstract says nothing about CO2, and the pattern it studies is regional rather than global. This study appears to have little to do with global warming, and it seems disingenuous to claim that it does.

  41. Re, Nota says June 17, 2011 at 10:21 pm

    Nota, are you not familiar with the proxy studies which purport to eliminate the MWP? This paper has to do with the proxy used in those studies, but you must know this???

    BTW, some of these studies were far more regional then this one, “One tree to rule them all, and in the darknesss bind them”

  42. Hi guys,

    the rhythm is quite exactly Sun spot cycle, when I verified it between 1850 and 2010. The variability seems also to have, let’s say not so tight relation to absolute number of Sun spots. So originator for the cycle is Sun, definitely.

    As my personal opinion, the increased variability is because of decreased average humidity / energy content of the atmosphere, which makes climate more vulnerable to changes in the Sun activity. Which in turn shows that actually the climate is cooling (lower energy), not warming, which should show higher energy.

    Please find more infomration about ultimate regulatory model in book Short history of temperature in site.

    Br Markku

  43. Tree rings are also a reasonable proxy for atmospheric CO2 content. Temperature-NO.

  44. If nothing else, the study demonstrates why Albert Hammond would write a song in 1972 claiming “it never rains in Southern California.”

  45. Here’s some info on a Jeffrey Pine planted here in 2004 in western Md. I post this season’s (yes, its upward growth has finished this year already) & the previous 2 season’s growth. I don’t want to go back in time any further ’cause the last 3 yrs I consider it to be fully “established” & no remnant effect of transplant shock. The temp data (the precip is my own) is obtained from a nearby well-maintained NWS station (tho definitely UHI-affected, IMO). Also, this tree’s current-season growth always seems to come from the previous season’s manufacture & storage of food & the resultant terminal-bud development in that year (and candle-growth is finished by mid-June). Many trees seem to be like this, but there are exceptions. Some species can take advantage of current conditions and produce a second or even third flush of growth during the season, depending on conditions.

    2009 season — 30 inches growth. Previous season May thru Sept precip & Temp anomaly, 22.35″ -.5 degF
    2010 season — 21 inches growth. Previous season May thru Sept precip & Temp anomaly, 18.37″ +.7 degF
    2011 season — 12 inches growth. Previous season May thru Sept precip & Temp anomaly, 15.71″ +4.0 degF

    The correlation to previous-season precip is obvious, but there’s almost an anticorrelation to temps. 2010 definitely had a hot, dry growing season.

    Not much science, just a random sample of growth vs temp & precip from an easily-observable tree (the annual branch whorls are quite apparent). But a tree-thermometer it isn’t. More like a tree rain gauge for the previous growing season.

  46. I completely, 100%, dispute using tree rings as proxies for both precip and temperature. Until someone comes up with a reliable, solid method for separating the precip forcing of tree ring growth from the temperature forcing, none of the proxies using tree rings are worth anything at all.

    It is obvious that BOTH are forcings for tree rings. But each does how much? And is it unique at each site? And even if they get that data for the present, does it mean that today’s data holds true for the past? Not at all.

    If both are forcings, no one can use tree rings as proxies for either one.

  47. That wave pattern reminds me of two cycles, one slower, one faster, that periodically perform in and then out of sync.

  48. Without reading the paper, I note that the PDO affects the west coast of North America.

    Here’s a lead I stumbled across, a study of growth/retreat of a modest glacier in the coastal mountains north of Vancouver B.C.

    “Mass balance and streamflow variability at Place Glacier, Canada, in relation to recent climate fluctuations” by R.D.Moore and M.N. Demuth, in journal “Hydrological Processes”, 2001, vol. 15, no18, pp. 3473-3486.

    This bit from the abstract shows part of what they did: “Place Glacier’s winter and net balances are correlated with the Pacific Decadal Oscillation (PDO). ….. A reconstruction of net balance extending back to the 1890s, based on a regression with winter precipitation and summer temperature, displays decadal-scale fluctuations consistent with the PDO.”
    Payment is required to read the whole article.

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