Even CNN Sees the Light

11,000 years ago, our ancestors survived abrupt climate change Paleoclimatologists, who study climates of the past, know that Earth's climate was not as stable for our ancestors as it has been for us. These abrupt, harsh changes could mean life or death, often forcing whole populations to move if they wanted to survive. For example, one well-studied event 8,200 years ago was a sudden cold shift that lasted over a century, recorded in Greenland ice cores and within the fossil record across Europe, the researchers said. It occurred when the North American ice sheet decayed after the last ice age and released meltwater into the North Atlantic Ocean, disrupting the currents that brought heat to Western Europe. This triggered large-scale population crashes in northern Britain and large cultural changes in southern Europe, they said.  CNN! BONUS: AL GORE: We're Running Out Of Time On Global Warning