Every 1500 years we have a Dansgaard-Oeschger oscillation. This is a "sudden" rise in temperature of 3-8 degrees. It is "sudden" taking about 40 years. This causes the polar ice caps to melt. As the freshwater changes the salinity of the Atlantic Ocean, its currents stall.

This is followed by a Bond event where the temperatures drop. As you may know, the Dark Ages occurred in Europe starting around 500 AD. On the other hand, I think Southeast Asia flourished.

Weather forecasts describe what will happen over the next few days. This describes part of the true story behind "Climate Change."