"High levels of carbon dioxide emissions in the atmosphere mean the next ice age is unlikely to begin for at least 1,500 years, an article in the journal Nature Geoscience said on Monday."

"Concentrations of the main gases blamed for global warming reached record levels in 2010 and will linger in the atmosphere for decades even if the world stopped pumping out emissions today, according to the U.N.'s weather agency.

An ice age is a period when there is a long-term reduction in the earth's surface and atmospheric temperature, which leads to the growth of ice sheets and glaciers.

There have been at least five ice ages on earth. During ice ages there are cycles of glaciation with ice sheets both advancing and retreating."

Nina Chestney reports for Reuters January 10, 2012. [2]