It is my firm belief that the climate is mostly self-regulated. Something causes it to get warm.. something changes to cool it off again.
Only something like the sun changing, a comet, or massive volcanic explosion can have any big impact.
One set of wobbles when Earth is farthest from the sun can cause significant cooling, and a different set of wobbles when Earth is closest to the sun can cause significant warming.
The wobbles, and Earths elliptical path around the sun, mean that the angle of sunlight striking the Earth, and the surface area being illuminated, are constantly changing.