Chilling climate revelations from a previous ice age

About 14,000 years ago, the southwest United States was lush and green, home to saber-toothed cats and mammoths. Meanwhile, the Pacific Northwest was mostly grassland.

That all changed as the last ice age was ending. Climate changes might be expected with the melt of a global freeze, but what’s surprising is how quickly climate and rainfall patterns changed. According to research published Nov. 22, the collapse of an ice sheet in what is now western Canada triggered a reorganization of the jet stream over the course of about 100 years — a blink of an eye in geological time.