However, the past 50 years or so (1945-2000) appear to be different in several important respects to that earlier (1860-1944) period in the instrumental surface record:

 First,
it divides sharply at 1976/77 (see Figure 1) into an earlier period of slight cooling and a later period of pronounced warming.

 Second,
this division cannot be attributed to human-caused changes to the composition of the atmosphere, because anthropogenic emissions accumulate gradually and this change is abrupt, and because over the period 1958-2000, at least, there was no detectable warming of the atmosphere attributable to GHGs.  Therefore, this is not the greenhouse effect in action.

 Third,
although solar magnetic flux is high throughout the period (see Figure 2), nothing in this part of the record correlates with the observed temperature changes.

The most prominent climate-change event in the 20th century - the warming step-change at 1976/77 - was not caused by variations in solar activity nor by the greenhouse effect.  That much appears reasonably certain; but what then did cause the change?

 7.2  The beginnings of an explanation
A plausible answer to the puzzle is provided by Figure 20 from Guilderson and Schrag (1998) It shows a step-change in sea-surface temperatures in the tropical Pacific at the same time as that observed in atmospheric temperatures (see top graph in Figure 19).

These authors introduce their paper by saying:
 Several studies have noted that the pattern of El Niño-Southern Oscillation  (ENSO) variability changed in 1976, with warm (El Niño) events becoming more  frequent and more intense.  This “1976 Pacific climate shift” has been  characterized as a warming in SSTs through much of the eastern tropical Pacific.

They continue:
 Maximum temperatures (January to March) increased slightly after 1976 as a  result of more frequent ENSO warm phases, with no change occurring in non-El  Niño years.

Guilderson and Schrag then contrast this lack of any significant change in surface temperatures during the warm season with conditions during July to September, when the thermocline is higher (ie cold water lies nearer the surface), as follows:

 ..... the persistence of warmer SSTs during upwelling seasons since 1976, even  during cold phase (La Niña) conditions, suggests that a change in the ocean,  independent from wind forcing, might be involved.

At this stage, it is worth looking again at the middle line of the lower graph in Figure 17 which shows the ENSO Index for the second half of the 20th century.  There is indeed a significant change in its character at about 1976/77.

Figure 20 shows two cold spikes in about 1956 and 1989 which coincide with La Niña events, and prominent warm spikes at 1983 and 1998 (plus several lesser spikes between) which coincide with El Niño events.  Setting aside these ENSO impacts, the balance of the record shows unchanged sea-surface temperatures during the warm (January-March) season, and a step-change in the cold (ie upwelling) season.  Thus, the prominent warming event at 1976/77 appears to be the direct outcome of reduced upwelling by cold, deep water in the equatorial Pacific.

 7.3  Associated rate-of-change variations in length of day
Reduced upwelling implies momentum changes in the oceans.  Support for this assumption is provided by Figure 21 which draws on data17 which I have not yet encountered in published form.  The length-of-day changes displayed here appear to be beyond those which the quotidian interchange of angular momentum between Earth and atmosphere reasonably might be expected to produce.  The associated reduction of (cold) upwelling off San Francisco begins in 1978, following a major change of slope in the plot of LOD rate of change.

Here is circumstantial evidence supporting the hypothesis that the observed increase in sea-surface temperature in the equatorial and north-eastern Pacific since the mid-1970s is inertially driven.

 7.4  Where is the evidence for inertially-driven climate change?
With the exception of Mörner (1996, and several earlier papers), there has been little in the literature which seeks to relate inertial impacts to climate change; thus, up until now, published direct evidence hardly exists in peer-reviewed papers on this topic.

Furthermore, until the enormous quantity of research funding spent supporting the greenhouse effect hypothesis is counterbalanced to some small extent by money devoted to showing the greenhouse hypothesis to be mistaken, this situation will not change.  An example of how deeply the greenhouse cause has eroded scientific analysis is provided by Grevemeyer et al (2000), as discussed in Section 6.2.3 above.

______________________________________________________________________________________
17.  The data comes via Gary D. Sharp, Centre for Climate/Ocean Resources Study <http://www.monterey.edu/faculty/SharpGary/world> where the LOD data is attributed to ‘Naval Observatory’ (presumably that in Washington DC) in a CD entitled “California Weather” and compiled by Jim Goodridge of Mendocino.  I obtained this information through the good offices of Warwick Hughes.

In the case of people like me with interests outside the dominant paradigm, there is little choice but to trawl through the in-coming scientific literature in the hope of finding relevant material in papers whose main theme is incidental to our interest.

  7.4.1  Putting LOD changes to the test
What should we be looking for?  Regional changes which can be contrasted with lack of change in adjacent regions, could be an indicator of inertial influences.  On the other hand, changes which are of global coverage might be better explained by global factors such as variation in the incidence of cosmic rays in response to solar activity - or changes to the composition of the atmosphere caused by anthropogenic GHG emissions.

An obvious place to start our search is in the Caribbean , where as shown in Figure 5, there is a prominent warming at AD 1300-1400 (based on evidence from the reduced abundance of Globigerina bulloides in sea-bed sediment cores).  This warming contrasts with cooling at that time in the North Atlantic (see Figure 3), and  is almost certainly inertia-related.

An expansion of the Caribbean record for the period of the instrumental record is shown in Figure 22.  Here, the proxy record of G. bulloides abundance (heavy line) is inverted cf Figure 5, so it can be compared directly with sea-surface temperatures in the North Atlantic (dotted line).  Correspondence is generally very close, except in the periods 1890-1920 and 1970-90.

These intervals of miss-match, particularly the earlier one, appear to coincide with times of rapidly-changing LOD, as shown in Figure 23.  While this correlation is hardly compelling, I draw encouragement from it.  After all, if the Caribbean tracked the North Atlantic throughout, as it does in 1920-70, there would be little room for inertial influences in the 20th century.

  7.4 2  South Pacific: marching to a different drummer?
Over the 22 years of the available satellite temperature record for the lower atmosphere, the Southern Hemisphere has cooled, albeit slightly, in contrast to modest warming in the north, as shown in Figure 8(b).  It would be reasonable to expect, therefore, that the prominent warming step in sea-surface temperatures at 1976/77 in the equatorial and NE Pacific is not as prominent in the south.

Linsley, Wellington and Schrag (2000) cored a massive (ie of non-branching habit) colony of the coral Porites lutea from Raratonga at 21 S 160 0W.  Using a Sr/Ca proxy, they obtained a continuous record of South Pacific sea-surface temperatures from AD 1726-1997, as shown in Figure 24(a).

This record shows a pronounced cooling trend from the peak at 1740-60 to about 1940, with (marked with arrows) no less than 12 individual cooling events over the period of the record in which sea-surface temperature fell by more than 0.75 degrees C.
The last of these multiple cooling events can be seen more readily in Figure 24(b), an expansion of the record from 1920.  The sea-surface temperature peaked in 1976 and then declined sharply from 1977.  By 1988, SST at Raratonga had fallen by 2 degrees C, and it is still (1997) well below the 1976 level.

Also included in Figure 24(a) is a plot of the PDO index - reversed from that in Figure 16.  In short, the South Pacific at Raratonga behaves like the NE Pacific in reverse, at least since about 1920.  This is clear evidence of an inertial driver for Pacific sea-surface temperature changes.

 7.5  Demise of the ‘Greenhouse Effect’ hypothesis
If IPCC’s Greenhouse Effect hypothesis of global climate change was already moribund, it is now deceased.  You will recall that I quoted at length from the evidence by Jenkins of the (UK) Hadley Centre to the Senate Committee in Section 4.3.2 above.  He is faced with the problem that the greenhouse effect is in the first instance a phenomenon of the lower atmosphere, and a comprehensive satellite-derived  temperature record is available from 1979 that shows no substantial warming trend.

In a remarkable confirmation that Hadley Centre (read ‘IPCC’) ignores awkward facts, Jenkins says:
 What we have done is not use satellite measurements but measurements from  weather balloons and look at the trends in temperature that have occurred since  about 1960 to the present day in the atmosphere.  That has shown that the overall  trends in temperature in the atmosphere have not been very much different from  those at the surface which sees quite a clear warming in the atmosphere  reasonably similar to that at the surface overall for that period.

But the balloon record is essentially flat except for a single jump at 1976/77; this is not a ‘trend’.  It appears very likely that this jump - coinciding as it does with a marked sea-surface warming in the equatorial and NE Pacific - is a response to a major ocean-heat-transport-related event, and not to greenhouse.  This supposition is amply confirmed by the finding that the 1976/77 event has the form of an abrupt sea-surface cooling in the subtropical South Pacific.  This event is likely to be inertially-driven.

There can be no reasonable remaining doubt that this wide-spread, and in some locations extreme, climatic event is ocean-related - and little or nothing to do with anthropogenic changes to the composition of the atmosphere.  The last refuge of a doomed Greenhouse Effect hypothesis has gone.

You read it first here

© 2001  Bob Foster  Posted   9, April, 2001
www.globalwarming-news.com
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