Sir, I write in response to the letter of Prof Sumerhayes of 17. 7. 14, with particular reference to his comments on solar radiance and temperatures. In both of the cases quoted by Prof Summerhayes, he has chosen to ignore evidence that flatly contradicts, if not outright disproves, his arguments, and raises serious questions about the use and reliability of some proxy data sets to reconstruct past temperatures.
With reference to the sun and global average temperatures I include a graph of sunspot activity and global temperatures for the last four (21 to 24) solar cycles with the caption provided by the source (Space Science Research Centre, 2014).
I quote the SSRC statement of 10. 12. 14. with reference to this data and its implications for future short term (30 years) global temperatures:
"The rate of temperature decline on a 100-year trend line is the steepest seen during that time frame going back to 1914. The most recent multi-centennial climate epoch which began around 1830, has begun to reverse direction from a global temperature standpoint. The past period of generally increasing warmth for the Earth, which was caused by the Sun’s natural and regular cycles of activity, reached an average peak of warming between 2007 and 2008 as measured by global atmospheric temperatures in the lower troposphere. This change was observed in oceanic temperatures as early as 2003. Acting primarily under the influence of a repeating 206 year solar cycle, a new “solar hibernation” has begun, and is marked by a significant decline in the Sun’s energy output. Starting with solar cycle #24, this energy reduction has initiated an expected reversal from the past warm era to a new cold era... There has been no effective growth in global temperatures for 18 years...and polar regions have now displayed a consistent trend of colder temperatures and growth in sea ice."
SSRC further predicts that:
"...unless there is a significant unexpected and rapid change in the present declining solar activity trend, then a period of solar hibernation will follow" and that this will result in "either new 200-year cold weather records or 400-year temperature records and widespread climate and weather extremes. Both of these predictions would result in global average temperatures falling between 1.0 and 1.5 degrees C lower than the peak year of 1998". SSRC predicts that these changes will occur "in the next year or two".
Readers will be able to make their own judgements concerning the value of the graph and the comments made by Prof Summerhayes regarding solar radiation output, the "ample information" about Be10 and C14 values and temperatures in his letter referred to above, and further so in the light of NASA data that shows that maximum solar output occurred in the early years of this century, not the 1970s as Prof. Summerhayes' proxy data suggests.
The well known Maunder and Dalton Minima of solar counts and their possible effects on temperatures can be readily seen on the graph. Readers may also wish to consider Prof Summerhayes' reference to the GSL climate change statement (2013) and the assumptions upon which that was based. In view of the fact that the data presented in the graph above were available to the authors of that statement, and that these data were evidently either ignored or given little weight leads me at least to the conclusion that a single hypothesis was more important to those authors than an objective analysis and evaluation of all available data and hypotheses.
Prof Summerhayes' statement that because "IPCC numerical climate...models’ outputs match recent meteorological data well up to the present time…it cannot be said that anthropogenic global warming has been disproved by the models’ performance." is simply wrong. I stated in an earlier letter (16.10.13) that there have been over 30 iterations of the IPCC model, and that none of them have made any accurate prediction of temperature change: such "predictions" that have been made have been proved to be wildly wrong and have had to be "adjusted" post hoc in order to match the actual temperature record.
The IPCC have so exaggerated the importance of CO2 that even when they do include other variables in their model the results are hopelessly inaccurate. There are many models other than that of the IPCC which have successfully predicted recent meteorological data accurately - they only require that temperatures rise to the extent that they have done in the past three decades - the causes of those changes are irrelevant. Prof Summerhayes has again failed to make the distinction between correlation and causation and recognise that there may be any number of factors causing variation in global average temperatures, upwards or downwards, which is why we need multiple working hypotheses when trying to better understand complex natural phenomena.
I have also stated that global climate is a consequence of the interaction of two complex fluid-dynamic systems and that because the behaviour of both is chaotic, predicting their behaviour over the longer term is inherently impossible. This means that the close coupling between sunspot activity and temperatures in the past 400 years as illustrated on the graph above is both remarkable and worthy of further detailed analysis and assessment by groups without preconceived notions about what may or may not be causing temperature fluctuations during that time. The lack of coupling between CO2 concentrations and temperature over the same 400-year period is even starker and serves to reinforce my argument. The AGW hypothesis has singularly failed to predict or explain any of these variations and this should be sufficient ground for its rejection. Politics and the politics of academic science are the major impediment to this happening, which was the key to my original letter on this subject.
This brings me to my final point. I have repeatedly asked for but have not been given, incontrovertible evidence that changes in CO2concentrations cause significant changes in global temperature. Reference to laboratory experiments are invalid because these are closed systems whereas the Earth's atmosphere is an open system and by definition will behave in a completely different manner. It has not "been known" that there is a causal link between CO2 concentrations and temperature since the end of the 19th Century (Prof Summerhayes, Geoscientist letters; 17. 7. 14): it has been assumed that such a link exists and it is this that I and others are challenging in the tradition of good scientific practice. Nowhere in the writings of Gilbert is evidence presented to demonstrate that an increase in CO2 in the Earth's atmosphere will cause an increase in temperature, only that the two are correlated.
Gilbert's assumption also underpins the books on planetary atmospheric science quoted by Prof. Summerhayes and means that they too are of questionable value: they are based on unproven assumptions which have achieved the status of unchallengeable myth. I have asked for evidence, not opinion, and I am still waiting for it. No matter. because an answer will be provided within a decade when we will all be able to observe directly the global average temperature trend. If temperatures do start to fall as predicted by the solar model above, the reaction of supporters of the AGW hypothesis will be very interesting and informative.
In the meantime I will concern myself with more acute and worrying environmental problems including among others, the pernicious spread of plastic waste, (C. Mackenzie, Soapbox: 7 August 2014).
Stephen W Foster.