[NeilBlanchard]

Our planet wobbles, and this changes the climate without changes in the carbon dioxide:

From Hockey Stick to Ski Jump | Climate Denial Crock of the Week

http://www.youtube.com/watch?v=xMZSu...layer_embedded

The gradual changes through the Holocene were driven by changes in Earth’s rotation, says Marcott. The planet is tilted about 23° relative to the plane of its orbit, and this tilt increased early in the Holocene before decreasing again. “It sort of wobbles,” Marcott says. A greater tilt increases the amount of sunlight at the poles during summer, and this keeps the planet warmer.

If humans had not begun warming the planet by releasing greenhouse gases, Earth would eventually return to an ice age. “If we were following the orbital trend we’d still be cooling,” Marcott says.