The Younger Dryas Event

In reworking my manuscript in hopes of publication I found new research that caused me to totally rewrite the Younger Dryas Event. During the last part of the Pleistocene the climate was warming up. In Central Texas it was wetter as well, with increased forest cover. It was during this period when the First Texans showed around 18,000 years ago. The Clovis period marked a spike in population about 13,000 years ago, then Bam! everything changed close to 12, 900 years ago. The temperature in the Northern Hemisphere dropped in just a decade or so to where it was during the Last Glacial Maximum 20, 000 years ago. It was the beginning of the end for megafauna like mammoths and life for the Clovis people was no longer so easy. The trigger that set off the Younger Dryas event is the subject of fierce argument among Paleo-climatologists, all manner of scientists, archeologists, and others concerned with deep history. Among the theories I’m sifting through the most exciting is the possibility of a comet strike in Greenland, but the evidence is piling up against that one. Another hypothesis argues that melting glacial water overloaded a giant lake that burst and loaded the North Atlantic with fresh water, screwing up the convection belt. There’s another odd one about a cosmic burst above the ozone layer. I’m going to have to go with the one supported by two or three Texas sites – a really big volcanic explosion in Germany that dusted the globe with a layer shown to be volcanic dust. The timing is close, within a hundred years. The Clovis mammoth hunters had to change their hunting kit to Folsom and start to target the now extinct Bison antiquus, a larger type of bison than today’s buffalo. The part I haven’t figured out yet is why this cold period – cold enough to chase the black-tailed jackrabbit from the archeological record in Texas – lasted a thousand years. Volcanos can’t do that.