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.
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
Tree rings are also a reasonable proxy for atmospheric CO2 content. Temperature-NO.
In 2006 Pederson et al published a study of drought variability 1540-2000 for Glacier National Park based on tree ring analysis. The 20th century was not remarkable compared to the full record, except for the extreme drought in the 1920s and 1930s.
http://www.fs.fed.us/psw/cirmount/wkgrps/ecosys_resp/postings/pdf/pederson_etal2006.pdf
More on Glacier NP…..
The wettest period was about 1780-1830, around the time of the Dalton Minimum. Now, one data point does not make a trend, but if the New Mexico papers are correct about a weak sun for a few decades….hang on to your rain gear.
http://www.fs.fed.us/psw/cirmount/wkgrps/ecosys_resp/postings/pdf/pederson_etal2006.pdf
OK, just one more about Glacier NP,,,,
From a 2009 article about a 1971 interview with members of the Blackfeet tribe – tribal memories are that the glaciers peaked in the early 1700s, after having almost disappeared 1000 years ago.
http://www.longrangeweather.com/ArticleArchives/BlackfeetIndians.htm
Montana had a MWP and a LIA!!
If nothing else, the study demonstrates why Albert Hammond would write a song in 1972 claiming “it never rains in Southern California.”
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.
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.
That wave pattern reminds me of two cycles, one slower, one faster, that periodically perform in and then out of sync.
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.