Gems level up and their requirements increase as they grow in power, so an intelligence based skill such as Cold Ring will have to stay at a low level in order to be usable by a strength heavy character, but technically all classes have all skills open to them .

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Tree ring data from Patagonia in South America show cold periods from 1270 to 1380 and from 1520 to 1670.

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In North America, Laki has been blamed for the starvation of Inuit populations from severe cold in northwestern Alaska, based on Inuit oral history as well as tree-ring density data investigated by Gordon Jacoby and others, who estimated that conditions were about 4 degrees Celsius colder than the mean.

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