Dr David Evans has proposed a new theory that he believes demonstrates the link between the Sun’s total solar irradiance (TSI) and the Earth’s climate. The idea that TSI and the Earth’s Climate are linked is not a new or novel theory. Evan’s has built a computer program that provides a time delay between a change in TSI and the time that climate begins to respond. He believes the key to his program is the use of “notch filter” similar to those used in the communications industry to filter out “noise”.
He also is asking for peer review of this program via “crowd sourcing”. Reading the comment sections of the sites where he has posted his theory and provided much of the coding, he certainly has been successful in getting comments. At the time of my last survey, the comments he has received are mostly positive but some others are skeptical.
For this study, Evans derived a new transform that he calls the “optimal Fourier transform (OFT)” for this paper. This transform provides the “notch”. One commenter suggested that the use of another type of Fourier transform would improve Evan’s program and appears that Evans agrees. (I did take a course in Laplace Transforms, but not being an Electrical Engineer, I have forgotten what I learned. This comment is a way of letting the reader know that I am unable to intelligently comment on the math used in Evans’ program. )
WHY IT’S GOING TO COOL
“The reason for the cooling is the dramatic fall in solar radiation that started around 2004. Here is a graph of solar radiation since 1610, when sunspots were first recorded. The brown line is the solar radiation, and it peaks every 11 years or so because of the sunspot cycle. We put an 11-year smoother through it to give us the red line, which shows the trends in solar radiation.” (Click on charts for improved clarity.)
Figure 1
Evans says there have been three steep falls in TSI in the last 400 years and each of these falls have been accompanied by major global cooling.
That the global temperature has fallen in sync with the drop off of TSI appears to be an awfully good correlation. But many skeptics as well as warmers argue that it must have been for some other reason other than TSI because (look at the vertical axis) the total change in TSI is too little to be of consequence.
This blog has always proposed that the Sun is the major forcing agent in global climate. Perhaps the causation is not the TSI, but I continue to believe the something correlated to the Sun’s activity is the causation. Having said that, time to move back to Evans’ theory.
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The diagram shows the sunspot numbers plotted against time. The three Grand Episodes are marked by their different colors. They are separated by vertical black lines.
Climate Change Sanity 