Saturday, June 11, 2011

New paper shows much higher sea surface temperatures PRIOR to the rise in CO2

A paper published online yesterday in the journal Paleoceanography shows Nordic sea surface temperatures were as much as 6C higher than the present during the Holocene Climate Optimum (~ 9500 to 6000 years ago) and a "general cooling trend" over the past 7000 years. The paper finds changes in solar energy impacting the Earth (solar insolation) explain the natural cycles of cooling and warming seen in the proxy reconstruction. The study results clearly show no correlation with CO2 levels and once again demonstrate how the Sun controls climate, not CO2.




August Sea Surface Temperatures in the top graph show the Holocene Climate Optimum (HCO) was much hotter than the present and a general cooling trend over the past 7000 years. Note the present is at the left side of the graph & x axis legend is "Calendar years before the present" The last major ice age ended about 11,000 years ago.


PALEOCEANOGRAPHY, VOL. 26, PA2220, 15 PP., 2011

doi:10.1029/2010PA002002



Holocene climate variability of the Norwegian Atlantic Current during high and low solar insolation forcing



K. S. Berner, et al



A high-resolution sediment core from the Vøring Plateau has been studied to document the centennial to millennial variability of the surface water conditions during the Holocene Climate Optimum (HCO) and the late Holocene period (LHP) in order to evaluate the effects of solar insolation on surface ocean climatology. Quantitative August summer sea surface temperatures (SSSTs) with a time resolution of 2–40 years are reconstructed by using three different diatom transfer function methods. Spectral- and scale-space methods are applied to the records to explore the variability present in the time series at different time scales. The SSST development in core MD95-2011 shows a delayed response to Northern Hemisphere maximum summer insolation at ∼11,000 years B.P. The record shows the maximum SSST of the HCO to be from 7.3 to 8.9 kyr B.P., which implies that the site was located in the regional warm water pool removed from the oceanic fronts and Arctic waters. Superimposed on the general cooling trend are higher-frequency variabilities at time scales of 80–120, 210–320, 320–640, and 640–1280 years. The climate variations at the time scale of 320–640 years are documented both for periods of high and low solar orbital insolation. We found evidence that the submillennial-scale mode of variability (640–900 years) in SSST evident during the LHP is directly associated with varying solar forcing. At the shorter scale of 260–450 years, the SSST during the LHP displays a lagged response to solar forcing with a phase-locked behavior indicating the existence of a feedback mechanism in the climate system triggered by variations in the solar constant as well as the role of the thermal inertia of the ocean. The abruptness of the cooling events in the LHP, especially pronounced during the onsets of the Holocene Cold Period I (approximately 2300 years B.P.) and the Little Ice Age (approximately 550 years B.P.), can be explained by a shutdown of deep convection in the Nordic Seas in response to negative solar insolation anomalies. These cooling events are on the order of 1.5°C.

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