Arctic Environmental Change of the Last Four Centuries

• Main Authors: J. Overpeck, K. Hughen, D. Hardy, R. Bradley, M. Douglas, B. Finney, K. Gajewski, G. Jacoby, A. Jennings, S. Lamoureux, A. Lasca, G. Macdonald, J. Moore, M. Retelle, S. Smith, A. Wolfe, G. Zielinski
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1997
• Subjects: Arctic; albedo; Climate change; Ice; permafrost; Sea ice
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.491.4643; http://faculty.eas.ualberta.ca/wolfe/eprints/Overpeck et al Science 1997.pdf

A compilation of paleoclimate records from lake sediments, trees, glaciers, and marine sediments provides a view of circum-Arctic environmental variability over the last 400 years. From 1840 to the mid-20th century, the Arctic warmed to the highest temperatures in four centuries. This warming ended the Little Ice Age in the Arctic and has caused retreats of glaciers, melting of permafrost and sea ice, and alteration of terrestrial and lake ecosystems. Although warming, particularly after 1920, was likely caused by in-creases in atmospheric trace gases, the initiation of the warming in the mid-19th century suggests that increased solar irradiance, decreased volcanic activity, and feedbacks internal to the climate system played roles. Global climate change is likely amplified in the Arctic by several positive feedbacks, including ice and snow melting that de-creases surface albedo, atmospheric stability that traps temperature anomalies near the surface, and cloud dynamics that magnify