Variations in the stable isotope content of the wood of tree rings are known to reflect variations in the sea’s surface temperature. The sea’s surface supplies the water for continental rainfall and the yearly uptake of water by trees. The isotope ratios in the wood thus provide a record of past ocean temperatures. Variations in the sun’s output of heat may cause the changes in the temperatures of the seas. Analysis of the oxygen isotope content of Japanese cedar tree rings over 1,800 years provides evidence for cycles of 156 years, 124 years, 97 years, 88 years, 70 years, and 55 years. Other species of trees and other isotopes have similar lengths to their cycles. The tree-ring data closely parallel the mercury thermometer records that have been available since the seventeenth century. The records of cherry blossoming and lake thaws were also employed to validate the tree-ring data. Based on her work, Libby thinks that we are entering a cooling period, but that the warming impact of the greenhouse effect may modify this cycle projection.
Libby, Leona Marshall. “Evaluation of Historic Climate and Prediction of Near-Fuiure Climate from Stable-Isotope Variations in Tree Rings.” In Climate: History, Periodicity, and Predictability. Edited by Michael R. Rampino, John E. Sanders, Walter S. Newman, and L. K. Konigsson. New York: Van Nostrand Reinhold, 1987.
Hi Steve,
Real science found in the UN FAO too!
Since you’ve got this series going of historical stories, I thought you’d be interested in a little known 2001 report by the UN FAO, but important (I think). It is quite ironic that one side of the UN was making this report while the other side was producing the IPCC reports:
On my timeline, “ClimateGate:30 Years in the Making” (http://joannenova.com.au/global-warming/climategate-30-year-timeline/), I made the following entry in 2001:
UN FAO: EARTH WARMS AND COOLS EVERY 30 YEARS
The UN Food and Agriculture Organization sought to understand the effect of
climate change on long-term fluctuations of commercial catches and reported
that several independent measures showed “a clear 55-65 year periodicity”
(i.e. approx 30 year warming then cooling) over both short terms (150 years)
and long terms (1500 years). [146:1] The report also highlighted that the
current “‘latitudinal’ … epoch of the 1970-1990s” is in its final stage and a
“‘meridional’ epoch … is now in its initial stage.” [146:2] Latidudinal circulations have
corresponded to warm periods and meridional circulations to cool ones.
Here are the references:
[146]
1. Leonid Klyashtorin, “Climate Change and Long-Term Fluctuations…” (abstract), Food and Agriculture Organization of the UN, Rome, 2001
http://www.fao.org/documents/pub_dett.asp?pub_id=61004&lang=en
2. “Chapter 2: Dynamics Of Climatic And Geophysical Indices”
http://www.fao.org/docrep/005/Y2787E/y2787e03.htm#bm03
Perhaps this is worthy of a post itself?
Keep up the good work.
Very nice, Mohib!!!
Ironic…… http://wattsupwiththat.com/2011/02/14/pielk-sr-on-the-30-year-random-walk-in-surface-temperature-record/