Two thousand years ago, the Arctic remnants of a once-vast ice sheet started to grow again.
Two thousand years ago, the Arctic remnants of a once-vast ice sheet started to grow again. It was the beginning of a new glacial period, more conversationally known as the next ice age—but by the 1960s, summer temperatures were already so high that the ice sheet started to shrink. In other words, global warming ended a period of glaciation that had already begun.
“It was just getting started, everything was normal, the next glaciation was about to happen—and yet it stopped,” says Nicolás Young, a geochemist at the Lamont-Doherty Earth Observatory, part of the Columbia Climate School. “It’s a very powerful example of how we have jolted the system.”
In a new study published in the journal Science, Young, fellow Lamont climate-geochemist Joerg Schaefer and their colleagues describe their research on the Laurentide Ice Sheet, and his colleagues describe their research on the Laurentide Ice Sheet, which covered much of Canada and the northern United States from about 95,000 to 20,000 years ago. At its largest, it stretched from above the Arctic Circle to Illinois, and in places the ice was over two miles thick.
Read More: Columbia Climate School
