Global Signatures and Dynamical Origins of the Little Ice Age and Medieval Climate Anomaly

TitleGlobal Signatures and Dynamical Origins of the Little Ice Age and Medieval Climate Anomaly
Publication TypeJournal Article
Year of Publication2009
AuthorsMann, M. E., Zhang Z., Rutherford S., Bradley Raymond S., Hughes M.K., Shindell D., Ammann Caspar, Faluvegi G., and Ni F.
JournalScience
Volume326
Pagination1256 - 1260
Date Published11/2009
ISSN1095-9203
KeywordsLittle Ice Age, Medieval Climate Anomaly, paleoclimatology
Abstract

Global temperatures are known to have varied over the past 1500 years, but the spatial patterns have remained poorly defined. We used a global climate proxy network to reconstruct surface temperature patterns over this interval. The Medieval period is found to display warmth that matches or exceeds that of the past decade in some regions, but which falls well below recent levels globally. This period is marked by a tendency for La Niña–like conditions in the tropical Pacific. The coldest temperatures of the Little Ice Age are observed over the interval 1400 to 1700 C.E., with greatest cooling over the extratropical Northern Hemisphere continents. The patterns of temperature change imply dynamical responses of climate to natural radiative forcing changes involving El Niño and the North Atlantic Oscillation–Arctic Oscillation.

DOI10.1126/science.1177303