little ice age

5
Lile Ice Age Arash Saysan

Upload: arashpicture

Post on 12-Jan-2015

208 views

Category:

Technology


2 download

DESCRIPTION

 

TRANSCRIPT

Page 1: Little Ice Age

Li!le Ice Age

Arash Saysan

Page 2: Little Ice Age

What was the Li!le Ice Age? •  !e Li"le Ice Age (LIA) was a period of cooling that occurred a#er a warmer era known as the Medieval

Warm Period. While not a true ice age, the term was introduced into scienti$c literature by François E. Ma"hes in 1939. Climatologists and historians working with local records no longer expect to agree on either the start or end dates of this period, which varied according to local conditions. Some con$ne the Li"le Ice Age to approximately the 16th century to the mid-19th century. It is generally agreed that there were three minima, beginning about 1650, about 1770, and 1850, each separated by intervals of slight warming.

Page 3: Little Ice Age

When did the Li!le Ice Age occur? •  !ere is no agreed beginning year to the Li"le Ice Age, although there is a %equently referenced series of events preceding the

known climatic minima. Starting in the 13th century, pack ice began advancing southwards in the North Atlantic, as did glaciers in Greenland. !e three years of torrential rains beginning in 1315 ushered in an era of unpredictable weather in Northern Europe which did not li# until the 19th century. !ere is anecdotal evidence of expanding glaciers almost worldwide. In contrast, a climate reconstruction based on glacial length shows no great variation %om 1600 to 1850, though it shows strong retreat therea#er.

•  For this reason, any of several dates ranging over 400 years may indicate the beginning of the Li"le Ice Age:

•  * 1250 for when Atlantic pack ice began to grow •  * 1300 for when warm summers stopped being dependable in Northern Europe •  * 1315 for the rains and Great Famine of 1315-1317 •  * 1550 for theorized beginning of worldwide glacial expansion •  * 1650 for the $rst climatic minimum

•  Among the earliest references to the coming climate change is an entry in the Anglo-Saxon Chronicles dated 1046: "And in this same year a#er the 2nd of February came the severe winter with %ost and snow, and with all kinds of bad weather, so that there was no man alive who could remember so severe a winter as that, both through mortality of men and disease of ca"le; both birds and $shes perished through the great cold and hunger.”

•  In contrast to its uncertain beginning , there is a consensus that the Li"le Ice Age ended in the mid-19th century.

Page 4: Little Ice Age

What was its e"ect on History?

•  Brought colder winters to parts of Europe and North America. •  In the mid-17th century, glaciers in the Swiss Alps advanced, gradually engul$ng farms and crushing entire villages. •  !e %eeze of the Golden Horn and the southern section of the Bosphorus took place in 1622. •  !e population of Iceland fell by half, but this was perhaps also due to &uorosis caused by the eruption of the volcano Laki

in 1783. •  Iceland also su'ered failures of cereal crops and people moved away %om a grain-based diet.[16] !e Norse colonies in

Greenland starved and vanished (by the 15th century) as crops failed and livestock could not be maintained through increasingly harsh winters, though Jared Diamond noted that they had exceeded the agricultural carrying capacity before then.

•  In North America, American Indians formed leagues in response to food shortages. In Southern Europe, in Portugal, snow storms were much more %equent while today are rare. !ere are reports of heavy snows in the winters of 1665, 1744 and 1886.

Page 5: Little Ice Age

Source