Chilling Details

(Fox News) - Scientists at the University of Birmingham in Britain claim that greenhouse gases — which are normally associated with global warming — may have caused an ice age 630 million years ago.

The Daily Telegraph reports researchers studied limestone rocks and found that large amounts of greenhouse gas coincided with a period of prolonged freezing.

While pollution in the air is thought to trap the sun's heat in the atmosphere — causing global warming — this new research suggests pollution could have the opposite effect by reflecting the sun's rays back into space, making the earth's surface cooler. The lead investigator warns the earth could cool dramatically — perhaps creating another ice age — if greenhouse gases are not kept in check.