I prefer to think that it's caused by precession of the poles and wobble of the earth on it's axis...........
Hmm that that has a 27,000 yr period, unfortunately it does not fit the data.
Now the 100kyr wobble in earths orbital plain with respect to the solar system mean plane is a different matter:
http://newton.ex.ac.uk/aip/physnews.252.html#1
INTERPLANETARY DUST PARTICLES (IDPs) are deposited on the Earth at the rate of about 10,000 tons per year. Does this have any effect on climate? Scientists at Caltech have found that ancient samples of helium-3 (coming mostly from IDPs) in oceanic sediments exhibit a 100,000-year periodicity. The researchers assert that their data, taken along the Mid-Atlantic Ridge, support a recently enunciated idea that Earth's orbital inclination varies with a 100-kyr period; this notion in turn had been broached as an explanation for a similar periodicity in the succession of ice ages. (K.A. Farley and D.B. Patterson, Nature, 7 December 1995.)
Farley & Patterson 1998, http://www.elsevier.com/gej-ng/10/20/36/33/37/32/abstract.html
Farley http://www.gps.caltech.edu/~farley/
Farley http://www.elsevier.nl/gej-ng/10/18/23/54/21/49/abstract.html
http://www.publicaffairs.noaa.gov/pr96/dec96/noaa96-78.html
ABRUPT CLIMATE CHANGE DURING LAST GLACIAL PERIOD COULD BE TIED TO DUST-INDUCED REGIONAL WARMING
Preliminary new evidence suggests that periodic increases in atmospheric dust concentrations during the glacial periods of the last 100,000 years may have resulted in significant regional warming, and that this warming may have triggered the abrupt climatic changes observed in paleoclimate records, according to a scientist at the Commerce Department's National Oceanic and Atmospheric Administration. Current scientific thinking is that the dust concentrations contributed to global cooling.
Spectrum of 100-kyr glacial cycle: Orbital inclination, not eccentricity Origin of the 100 kyr Glacial Cycle
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Ice Ages & Astronomical Causes Origin of the 100 kyr Glacial Cycle Figure 1-1 Global warming Figure 1-2 Climate of the last 2400 years
Figure 1-3 Climate of the last 12,000 years Figure 1-4 Climate of the last 100,000 years Figure 1-5 Climate for the last 420 kyr, from Vostok ice |
KRIKIES!! According to that last chart, we seriously over-due for a MAJOR cool down.
Wouldn't that just be fitting. The whole world is going ga-ga (sp?) over Global WARMING just at the time we're heading into a long-term ice age. Brilliant!
Why do you keep posting this 'science' stuff.
It is man that is heating the planet to the boiling point and killing all the whales and stuff!
Don't try to take the blame off George Bush and Standard Oil and put it on Gaia and the Universe!
You are only confusing the people with facts.
/sarc