Scientists from NASA and Columbia University, New York, have used computer modeling to successfully reproduce an abrupt climate change that took place 8,200 years ago. At that time, the beginning of the current warm period, climate changes were caused by a massive flood of freshwater into the North Atlantic Ocean.

The group used an atmosphere-ocean coupled climate computer model known as "GISS Model E-R" to simulate the climate impact of a massive freshwater flood into the North Atlantic that happened about 8,200 years ago after the end of the last Ice Age. As retreating glaciers opened a route for two ancient meltwater lakes, known as Agassiz and Ojibway, to suddenly and catastrophically drain from the middle of the North American continent. At approximately the same time, climate records show that the Earth experienced its last abrupt climate shift. Scientists believe that the massive freshwater pulse interfered with the ocean's overturning circulation, which distributes heat around the globe. According to the record of what are known as climate proxies, average air temperatures apparently dropped fell as much as several degrees in some areas of the Northern Hemisphere.