THE ‘LITTLE ICE AGE’: RE-EVALUATION OF AN EVOLVING CONCEPT
Article first published online: 22 JUL 2005
Geografiska Annaler: Series A, Physical Geography
Volume 87, Issue 1, pages 17–36, March 2005
How to Cite
MATTHEWS, J. A. and BRIFFA, K. R. (2005), THE ‘LITTLE ICE AGE’: RE-EVALUATION OF AN EVOLVING CONCEPT. Geografiska Annaler: Series A, Physical Geography, 87: 17–36. doi: 10.1111/j.0435-3676.2005.00242.x
- Issue published online: 22 JUL 2005
- Article first published online: 22 JUL 2005
- Manuscript received October 2004, revised and accepted December 2004.
- Little Ice Age;
- decadal variability;
- last millennium;
ABSTRACT. This review focuses on the development of the ‘Little Ice Age’ as a glaciological and climatic concept, and evaluates its current usefulness in the light of new data on the glacier and climatic variations of the last millennium and of the Holocene. ‘Little Ice Age’ glacierization occurred over about 650 years and can be defined most precisely in the European Alps (c. AD 1300–1950) when extended glaciers were larger than before or since. ‘Little Ice Age’ climate is defined as a shorter time interval of about 330 years (c. AD 1570–1900) when Northern Hemisphere summer temperatures (land areas north of 20°N) fell significantly below the AD 1961–1990 mean. This climatic definition overlaps the times when the Alpine glaciers attained their latest two highstands (AD 1650 and 1850). It is emphasized, however, that ‘Little Ice Age’ glacierization was highly dependent on winter precipitation and that ‘Little Ice Age’ climate was not simply a matter of summer temperatures. Both the glacier-centred and the climate-centred concepts necessarily encompass considerable spatial and temporal variability, which are investigated using maps of mean summer temperature variations over the Northern Hemisphere at 30-year intervals from AD 1571 to 1900. ‘Little Ice Age’-type events occurred earlier in the Holocene as exemplified by at least seven glacier expansion episodes that have been identified in southern Norway. Such events provide a broader context and renewed relevance for the ‘Little Ice Age’, which may be viewed as a ‘modern analogue’ for the earlier events; and the likelihood that similar events will occur in the future has implications for climatic change in the twenty-first century. It is concluded that the concept of a ‘Little Ice Age’ will remain useful only by (1) continuing to incorporate the temporal and spatial complexities of glacier and climatic variations as they become better known, and (2) by reflecting improved understanding of the Earth-atmosphere-ocean system and its forcing factors through the interaction of palaeoclimatic reconstruction with climate modelling.