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.
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| 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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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?
How long does it take for the Pacific to slosh from one side to the other – a decade? PDO?
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.
After Briffa gets through with his analysis of the data, that graph will look like the proverbial hockey stick.
Mainstream press is on the Univ. of Col. Sea Level Group doctoring data to show accelerating sea level rise.
http://www.foxnews.com/scitech/2011/06/17/research-center-under-fire-for-adjusted-sea-level-data/
Of course this was reported here a number of weeks ago.
Gotta love that settled science.
“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?
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.
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?
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.
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.
Stand by for a herd of trolls.
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?
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?
Trees are showing rainfall patterns. But the overall pattern is that rainfall has been normal. Maybe “normal” is not a pattern.
This is the perfect opportunity for a Singular Value Decomposition (SVD) statistical research project to find the area of the Pacific Ocean that is most associated with this cycle. There’s no guarantee that there is one, but based on other such studies, there also a good chance there is. See:
http://www.agu.org/pubs/crossref/2010/2009WR008053.shtml
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.
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.
heh, I pick stock market swings with tree ring data … they work for EVERYTHING …
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.
“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?
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.
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.
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.
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.