Spatio-temporal variability of the the climate on decadal to century scales
What is the Little Ice Age? What caused it? Is is a singular event, or is it only one of many climate changes on the century scale? And what happens to the climate system on decadal scales during these century-scale events?
Climate changes on the decadal to century scale are among the least understood of the scales of climate variability. A general discussion of the issue of scale in paleoclimatology can be found in Gajewski (1993). The Little Ice Age (approximately AD1450-1850) is an example of the variability of the climate system at this scale. There are records from some parts of the world - including Europe, western and eastern North America - that suggest generally cooler conditions during this time. The Medieval Warm Period is another example, which was recently discussed in a special issue of the journal Climate Change.
These questions are being investigated using a variety of approaches, including the development of new records of climate change at this scale, modeling the climate system and the analysis of databanks of proxy-climate indices. A example of the synthesis of a variety of records can be found in Overpeck, J., K. Hughen, D. Hardy, R. Bradley, R. Case, L. Doner, M. Douglas, B. Finney, K. Gajewski, G. Jacoby, A. Jennings, S. Lamoureux, G. MacDonald, J. moore, A. Ogilvie, M. Retelle, S. Smite, A. Wolfe, G. Zielinski. 1997. Arctic environmental change of the last Millennium. Science 278:1251-1256. You can find a copy of this study here. Two other attempts have been recently published (1998) in Nature.
New proxy-climate indicators are being developed to better understand past climate changes in the Canadian arctic. One record from Devon Island (Gajewski, K., P. Hamilton and R. McNeely. 1997. A high-resolution proxy-climate record from an arctic lake with annually-laminated sediments on Devon Island, Nunavut, Canada. Journal of paleolimnology 17:215-225) documented the impact of human-caused climate change of the 20th century using varve measurements and diatom abundance in a core with annually-laminated sediments. We are currently working on extending this record using new cores collected from this site in the summer of 1996.
See also a recent review of the methodology used to study the Little Ice Age and impacts on vegetation.
© University of Ottawa
If you are looking for additional information, please contact us.
Technical questions or comments about this site? Last updated: 2009.11.23