The 231,097 AD Ice Age was one of the most deadly ice ages in history. It began to take place in 220,000 AD when cold currents of the ocean prevented the warm currents from getting to the poles. World temperatures started to plummet. By 228,000 AD world temperatures plummeted to a average of -12°F. 231,097 AD is when the ice age was at 91% strength. Global temperatures plummeted to -60°F, the human population started to diminish. The ice age lasted 1.5 million years. By 1,731,097 AD the human population dwindled down to 8,000 from nearly 20 billion.