Guest Post by Willis Eschenbach
We have the ill-fated stillborn Copernicus Special Edition as an example of how those authors went about analyzing the possible effects of astronomical cycles. Let me put up a contrasting example, which is The 1,800-year oceanic tidal cycle: A possible cause of rapid climate change. Heck, it’s even got “cycle” in the title. Please be clear that I am not advocating for this study. or saying that this explains how the climate works. Instead, I am offering it as an example of a reasonable paper showing a real scientific investigation of the effect of sun-moon-earth cycles and conjunctions on the climate. From the abstract:
We propose that such abrupt millennial changes [rapid global cooling], seen in ice and sedimentary core records, were produced in part by well characterized, almost periodic variations in the strength of the global oceanic tide-raising forces caused by resonances in the periodic motions of the earth and moon.
A well defined 1,800-year tidal cycle is associated with gradually shifting lunar declination from one episode of maximum tidal forcing on the centennial time-scale to the next. An amplitude modulation of this cycle occurs with an average period of about 5,000 years, associated with gradually shifting separation-intervals between perihelion and syzygy at maxima of the 1,800-year cycle.
We propose that strong tidal forcing causes cooling at the sea surface by increasing vertical mixing in the oceans. On the millennial time-scale, this tidal hypothesis is supported by findings, from sedimentary records of ice-rafting debris, that ocean waters cooled close to the times predicted for strong tidal forcing.
And here is their Figure 1, showing the peak tidal strengths for the last several hundred years:
So why do I like this analysis of cycles, and yet I was so scathing about the analyses of cycles in the Copernicus Special Edition? The answer is simple: science, science, science.
First off, they make a clear statement of their claim—they propose that periodic changes in the strength of the oceanic tides affect the global temperature.
Next, they propose a mechanism—the strong tides stir up the deeper, colder ocean waters and bring them to the surface, cooling the globe.
Next, they connect the astronomical cycles to the earth through recognized and well understood calculations. There is no fitting of parameters, no messing with fractions. There is no mention of golden ratios, Titius Bode “law” calculations, the music of the spheres, or the planetary Hum. Just mathematical calculations of the strength of the tidal-raising forces, such as those shown in Figure 1. They’ve cited their data source in the caption. Note that what they show is the accurately calculated strength of a real measurable physical force, and not some theoretical superposition of some mystical confluence of the orbital periods of random planets.
And finally, they offer observational evidence to support their claim.
Hypothesis, proposed mechanism, mathematical calculations without tunable parameters, identified data, clear methods, observational evidence … plain old science, what’s not to like.
Now, is their claim right? Do strong tides stir up the oceans and bring cooler water to the surface? I have no clue, although it certainly sounds plausible, and the forces are of the right order of magnitude. I haven’t looked into it, and even if true, it’s a side issue in my world. But it may well be true, and they’ve made their scientific case for it.
Like I said, I offer this simply as an example to assist folks in differentiating between science on the one hand, and what went on in far too much of the Copernicus Special Issue on the other hand.
PS—While code and data as used would have been a bonus, this was published in 2000, which is about a century ago in computer years. However, I think I could recreate their results purely from their paper, in part because the mechanisms and calculations for planetary locations and orbits and tidal forces are well understood. So it’s not like trying to replicate Michael Mann’s Hockeystick paper of the same era, which could not be done until the code was published …