But Hansen said that we could stabilize the climate at 350 ppm. I’m devastated.
There is no agreed beginning year to the Little Ice Age, although there is a frequently 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. The three years of torrential rains beginning in 1315 ushered in an era of unpredictable weather in Northern Europe which did not lift until the 19th century. There is anecdotal evidence of expanding glaciers almost worldwide. In contrast, a climate reconstruction based on glacial length shows no great variation from 1600 to 1850, though it shows strong retreat thereafter.
For this reason, any of several dates ranging over 400 years may indicate the beginning of the Little 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 first climatic minimum.