Scientists say small changes in the way the Earth orbits the sun hold the key in major global changes in climate, like ice ages.

The Earth's next ice age is expected to begin in about 11,000 years -- unless human-caused global warming disrupts natural cycles. Barker said that without the Industrial Revolution, assuming fossil fuels had never been burned,

Scientists have determined exactly how Earth's orbit and tilt affect glaciation and deglaciation, based on the length of these parameters' cycles and clues hidden at the bottom of the ocean.