Bishop Hill A Tibetan temperature reconstruction
Dec 7, 2011 Climate: MWP H/T to Scientist for Truth for this paper from the Chinese Science Bulletin, which incorporates a reconstruction of temperatures from tree rings in Tibet.
Amplitudes, rates, periodicities, causes and future trends of temperature variations based on tree rings for the past 2485 years on the central-eastern Tibetan Plateau were analyzed. The results showed that extreme climatic events on the Plateau, such as the Medieval Warm Period, Little Ice Age and 20th Century Warming appeared synchronously with those in other places worldwide. The largest amplitude and rate of temperature change occurred during the Eastern Jin Event (343-425 AD), and not in the late 20th century. There were significant cycles of 1324 a, 800 a, 199 a, 110 a and 2-3 a in the 2485-year temperature series. The 1324 a, 800 a, 199 a and 110 a cycles are associated with solar activity, which greatly affects the Earth surface temperature. The long-term trends (>1000 a) of temperature were controlled by the millennium-scale cycle, and amplitudes were dominated by multi-century cycles. Moreover, cold intervals corresponded to sunspot minimums. The prediction indicated that the temperature will decrease in the future until to 2068 AD and then increase again.
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Reader Comments (55)
Now all that is needed is to overlay CET onto this (with suitable offsets to align the vertical position) and an interesting alternative to the 'Hockey Stick' can be obtained :-).
Look how well this proxy captures the (NH?) temperature rise since 1600.
Just an FYI over at the comments at the DM for the more regular commenter’s here :-
ZedsDeadBed, Truro, UK, 8/12/2011 12:27
It's a shame that nothing will be done as accountability in our socialist society is all about blame and not about accountability, ie this will fall on death ears.
The same was done with the UK CET temperature record with basically the same result and same prognosis: significant cooling followed by warming but not to the extent of the recent past followed by a general cooling trend.
http://www.vukcevic.talktalk.net/CET-NVa.htm
There are also data from other studies that find the same though those seem to concentrate mostly on the 60 cycle which does seem rather dominant in the series.
"The mean temperature of the late EJE (2.67C) was the highest in the 2485 years, even exceeding that of the second half of the 20th century (2.57C). In other words, the late 20th century was not the warmest period in history." --p. 2988
And, "(3) Rate of temperature variation. We calculated rates of temperature variation in 10-year intervals and found that the rate of temperature variation was highest in 362–390 AD (C2–W2) with a value 0.77C/10 a. The next highest rate (0.35C/10 a) was for the period 881–908 AD between W4 and W5. There were low rates of variation in two long-term intervals: 0C/10 a in 228 BC–362 AD and 0.01C/10 a in 1271–1545 AD. There was an apparent warming trend in the 20th century on the Plateau, with a rate of 0.11C/10 a during 1918–2000 AD; this is similar to what IPCC4 reported (0.13C/10 a) for the past 50 years [23]. These two values are higher than the global average rate (0.044C/10 a) during 1850–2008 AD [28]. In general, the calculations showed that the warming rate in the 20th century was not the highest in the past 2485 years." Emphasis added.