In the 15th century the climate moderated, but in the 16th century the average temperature began to cool for the next 300 years, resulting in what has been called the "Little Ice Age." During this time, alpine glaciers increased in size and advanced down river canyons. Winters were long and severe; summers short and wet. The vineyards in England vanished, and farming became impossible in the more northerly latitudes. Cut off from the rest of the world by an advancing ice pack, the Viking colony in Greenland perished.