Rapid Variations in Atmospheric Methane Concentration During the Past 110,000 Years

• Published in: Science
• Main Authors: Brook, Edward J., Sowers, Todd, Orchardo, Joe
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science (AAAS) 1996
• Subjects: Greenland; Dansgaard-Oeschger events; ice core
• Online Access: http://dx.doi.org/10.1126/science.273.5278.1087; https://www.science.org/doi/pdf/10.1126/science.273.5278.1087

A methane record from the GISP2 ice core reveals that millennial-scale variations in atmospheric methane concentration characterized much of the past 110,000 years. As previously observed in a shorter record from central Greenland, abrupt concentration shifts of about 50 to 300 parts per billion by volume were coeval with most of the interstadial warming events (better known as Dansgaard-Oeschger events) recorded in the GISP2 ice core throughout the last glacial period. The magnitude of the rapid concentration shifts varied on a longer time scale in a manner consistent with variations in Northern Hemisphere summer insolation, which suggests that insolation may have modulated the effects of interstadial climate change on the terrestrial biosphere.