--while I agree that climate changes, this isn't the cause, IMHO--
It would appear to be a potentially strong initiator. The cause lay in what factors come in to play with a change in orbit that would induce significant change in climates.
Some reference material on the subject:
Ice Ages & Astronomical Causes
Brief Introduction to the History of Climate
by Richard A. Muller
And
Origin of the 100 kyr Glacial Cycle
Richard A. Muller* and Gordon J. MacDonaldSince orbital inclination does not affect insolation, we must search for another mechanism relating it to climate. The only plausible one we have found is accretion of interplanetary material: meteoroids and dust. As the orbit of the earth changes, it passes through different parts of the sun's zodiacal ring, and encounters different regions of material. Changes in inclination will be reflected in changes of accretion. Glacier growth occurs during periods of low inclination, and recession during times of high inclination. We emphasize that this mechanism is speculative, and there is no known meteoroid or dust band that satisfies all the properties that we require, although it is possible that such a band could have been missed. We will offer some indirect evidence that accretion does vary with the orbital inclination.
Interplanetary dust accreting on the sun has previously been proposed as a driver of the ice ages (ref 26, 27). Clube (ref 28) discussed the possibility of accretion from a single large and unknown meteoroid stream affecting the Earth's climate, but he did not draw any connection to the periodicity of glacial cycles. Hoyle and Wickramasinghe (ref 29) calculated the effect that accreting dust in the atmosphere could have on the greenhouse effect through the seeding of ice crystals, and they speculated that such accretion could have been responsible for the Little Ice Age. At a meeting of the Royal Astronomical Society reported by G. Manley (ref30), Hoyle discussed the possibility that accretion could remove enough stratospheric water to reduce the greenhouse effect and causing cooling. Stratospheric dust can also be an effective scavenger of other greenhouse gases, such as ozone.
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.
Hmmmm an interesting little recent tidbit:
Mysterious glowing clouds targeted by NASA
26 May, 2006
High-altitude noctilucent clouds have been mysteriously spreading around the world in recent years (Image: NASA/JSC/ES and IA)
