Wobbly Universe

This article will look at the cyclical aspects of Solar Cycles that affect the earth's Climate.

An article by Thomas J. Crowley, Published July 14, 2000 Science, 289: 270-277: Causes of Climate Change Over the Past 1000 Years.

Abstract:

"Recent reconstructions of northern hemisphere temperatures and climate forcing over the last 1000 years allow the warming of the 20th century to be placed within a historical context and various mechanisms of climate change to be tested. Comparison of observations with simulations from an energy balance climate model indicate that as much as 41-64% of pre-anthropogenic (pre-1850) decadal-scale temperature variations were due to changes in solar irradiance and volcanism. Removal of the forced response from reconstructed temperature time series yields residuals that show similar variability to control runs of coupled models, thereby lending support to the models' value as estimates of low-frequency variability in the climate system. Removal of all forcing except greenhouse gases from the ~1000 year time series results in a residual with a very large late 20th century warming that closely agrees with the response predicted from greenhouse gas forcing. The combination of a unique level of temperature increase in the late 20th century and improved constraints on the role of natural variability provides further evidence that the greenhouse effect has already established itself above the level of natural variability in the climate system. A 21st century global warming projection far exceeds the natural variability of the last 1000 years and is greater than the best estimate of global temperature change for the last interglacial."

To Crowley's graph I have added a regular 123 year cycle and it can be seen to fit the minima in the graph rather well. On this basis another minimum should occur around 2060. There are clearly two other periods of solar variation happening in the graph. Firstly an 11 year period, showing only in the more recent years and being the sunspot cycle period. Secondly,. a longer cycle that occurs less than twice in the full 1,000 years plotted here, with a period of about 600 years.

This longer cycle had minima in around 1070 and 1700 and so we are close to a maximum right now with the next minimum not due for some 300 years.

A period of 600 years was noted by Edward R. Dewey in the formation of major religions. This strange fact may also be connected with the rise and fall of major civilisations, with new prophets appearing at around the peak in civilisations.

The major world religions started at the following times are noted:

~1200 BC  Moses     Judaism
 ~600 BC  Buddha    Buddhism
         (also Lao Tze, Confucius, Zoroaster)
   ~0     Christ    Christianity
 ~600 AD  Muhammad  Islam
~1200 AD  (none)
~1800s    (Bahai, Jehovah's Witness, Mormons, Theosophy, others)

The civilisations may be interpreted as Ancient Greece then Rome, Arab Empire, the Renaissance, the Industrial Revolution.

There is a tendency for scientists today to see everything as one-off events, something which I consider to go against the main principle of science which is to find patterns of behaviour. Of course the patterns must be solidly statistically based to be of any use. There is plenty of data to show that the 11 year and 123 year cycles are real. The 600 year cycle is on a little less certain footing, but should be considered as a reasonable candidate for existing.

We are at present right at the peak or just past it on both the 123 year and 600 year (if it is real) solar cycles. That gives some solace to those who are trying to make efforts to alter potentially damaging human behaviour.

See Also:
Causes of Climate Change Over the Past 1000 Years
Humans vs Sun as cause for climate change
Astronomer Sallie Baliunas on sunspots, global warming, ...
Global Warming - Humans and/or the Sun? ... and more!
Sun more active than for a millennium
Sally Baliunas inteviewed on Solar Fluctuations and Global Warming
Interview: James Lovelock on Climate Change
Humans, Cycles, Sun or Ice-ages - What affects our climate most?
Sun's fickle heart may leave us cold