The Maiankovitch Theory
"For the period from about 22,000 to 18,000 BP (Before Present), world temperatures fell lower than at any time since. And though the average temperature drop was just 10° F (6°C) colder than at present, it was enough to greatly shift the balance of winter snowfall and summer melting.
Why such long term ups and downs in the world climate? The causes are still poorly understood, but climatologists suspect a combination of reasons. The earth is not always the same distance from the sun, and it cools off at maximum distance. It periodically passes through clouds of cosmic dust, which block the sun's rays, as do major periods of volcanic eruptions. And the sun's energy, as shown by sunspot activity, fluctuates in a cyclic way.
Evidence from nearshore seabottom core samples indicate that at least 17 “ice ages” have occurred during the past two million years. During the most recent one, alpine glaciers much larger than these flowed down from the mountains surrounding the Salish Sea. Moving at a rate of up to a mile every ten years, the glacial fronts advanced far down into the lowlands, widening many of the V shaped river valleys below us into classic U shaped glacial valleys. At the lowland ends of these valley glaciers, where melting eventually matched the foreward thrust, the ice front dropped long piles of rock debris (terminal moraines) as evidence of their massive presence.
Ironically, the alpine glaciers were already in full retreat, far back up into the mountains, when a great ice sheet began its invasion from the north... "
Then we have the earth change in tilt to fold in every 41000 years
I suspect the beat frequency of the two cycles produces the Glacial cycle. but I will never live long enough to prove it, however, I feel confident that no tax will change it.
