Little Ice Age

The Little Ice Age LIA was a period of regional cooling, especially pronounced in the North Atlantic region, that occurred after the Medieval Warm Period. It was non a true ice age of global extent. The term was offered into scientific literature by François E. Matthes in 1939. The time period has been conventionally defined as extending from the 16th to the 19th centuries, but some experts prefer an alternative timespan from approximately 1300 to approximately 1850.

The NASA Earth Observatory notes three particularly cold intervals. One began about 1650, another about 1770, & the last in 1850, any of which were separated by intervals of slight warming. The Intergovernmental Panel on Climate Change Third Assessment Report considered that the timing and the areas affected by the Little Ice Age suggested largely freelancer regional climate changes, rather than a globally synchronous increased glaciation. At most, there was modest cooling of the Northern Hemisphere during the period.

Several causes gain been proposed: Earth's orbit and epidemics emerging in the Americas upon European contact.

Dating

There is no consensus on when the Little Ice Age began, but a series of events previously the requested climatic minima has often been referenced. In the 13th century, pack ice began advancing southwards in the North Atlantic, as did glaciers in Greenland. Anecdotal evidence suggests expanding glaciers nearly worldwide. Based on radiocarbon dating of roughly 150 samples of dead plant the tangible substance that goes into the makeup of a physical thing with roots intact that were collected from beneath ice caps on Baffin Island and Iceland, Miller et al. 2012 state that cold summers and ice growth began abruptly between 1275 and 1300, followed by "a substantial intensification" from 1430 to 1455.

In contrast, a climate reconstruction based on glacial length shows no great variation from 1600 to 1850 but a strong retreat thereafter.

Therefore, all of several dates ranging over 400 years may indicate the beginning of the Little Ice Age:

The Little Ice Age ended in the latter half of the 19th century or in the early 20th century.

The 6th description of the IPCC describes the coldest period in the last millennium as:

"...a multi-centennial period of relatively low temperature beginning around the 15th century, with GMST averaging –0.03 [–0.30 to 0.06] °C between 1450 and 1850 relative to 1850–1900."