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OK, imagine the earth is like a ball of wool with a knitting needle stuck through it. The needle represents the "spin axis" around which the Earth rotates. That axis is essentially "fixed" in space, relative to the stars - when we look up into the sky at night, we see the stars appear to rotate around a fixed point (called the "celestial pole"). For people in the Northern hemisphere there happens (by pure chance) to be a bright star near that point, which we call the "pole star", in the constellation of "Ursa Minor" - the "Little Bear".
OK so far?
Except - it's not really "fixed"; it "wobbles" in a slow circle, taking 26,000 years to do a complete circuit. This was discovered by a Greek astronomer called Hipparcos, who probably lives in the late 2nd century BC. In Hipparcos' time, a completely different star (called "alpha Draconis") was close to the pole, and "our" pole star was nowhere near the pole.
There is pretty strong evidence that the precessional cycle has some connection with the onset of ice ages on Earth, although nobody currently understands what the causal mechanism is. So yes, precession probably is connected with climate change in a fairly extreme way!
Over the course of a single human lifetime (or even the course of the lifetimes of a "civilization") it's such a slow process that it's not going to have any effect (other than being a mathematical effect that you need to take into account if you're doing accurate "celestial navigation").
Any help?
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