Beginning about 1450 A.D. there was a marked return to colder conditions. This interval is often called the Little Ice Age, a term used to describe an epoch of renewed glacial advance. Although many regions of the world experience cooling during the period 1450 to 1890 A.D., its use has been criticised because it could not conclusively be considered an event of global significance (Bradley & Jones, 1992). Nevertheless, within the framework of Holocene climate fluctuations, its terminology may be justified. Since this period overlaps with the advent of instrumental measurement of climate indices, considerably greater confidence can be attributed to the proxy reconstructions (e.g. tree rings, ice cores, periglacial features) through the use of calibration techniques.
There is considerable evidence that the Little Ice Age consisted of two main cold stages of about a century’s length (Bradley & Jones, 1992). These occurred in the seventeenth an nineteenth centuries, with relative warmth arising in the sixteenth and eighteenth centuries. Glaciers advanced in Europe, Asia and North America, whilst sea ice in the North Atlantic expanded with detrimental effects for the colonies of Greenland and Iceland (Lamb, 1982).