The main cause of a rapid global cooling period, known as the Big Freeze or Younger Dryas - which occurred nearly 13,000 years ago - has been identified thanks to the help of an academic at the University of Sheffield.
A new paper, which is published in Nature today (1 April 2010), has identified a mega-flood path across North America which channelled melt-water from a giant ice sheet into the oceans and triggering the Younger Dryas cold snap.