By Sid Perkins
Field studies in Russia indicate that massive peat bogs there may have been a major source of atmospheric methane just after the end of the last ice age.
Chemical analyses of the gases trapped in ice cores drilled from sites around the globe have revealed that the concentration of methane in Earth’s atmosphere increased dramatically between 11,500 and 9,000 years ago. Subtle differences among the cores suggest that much of that new methane–whatever generated it–originated in the Northern Hemisphere, says Glen M. MacDonald, a paleoclimatologist at the University of California, Los Angeles (UCLA).