Study Finds Laurentide Ice Sheet Began Re-expanding 2,000 Years Ago Before Warming Reversed It
A Science study finds the Laurentide Ice Sheet reached its smallest extent about 3,600 years ago and began growing again roughly 2,000 years ago, a trend that continued until human-caused warming reversed it around 1960.
The Barnes Ice Cap is the last surviving fragment of the Laurentide Ice Sheet, the largest of the Pleistocene ice sheets. At its peak, the Laurentide buried most of Canada under about two miles of ice and locked away roughly 80 meters of sea level, the report said. As the enormous dome thinned through the Holocene, its margin withdrew onto Baffin Island; what remains today is the deflated core of a mass that was once two miles thick.
The study shows that the Laurentide reached its smallest size about 3,600 years ago and then started re-expanding roughly 2,000 years ago. The team interprets that re-expansion as the opening move of the next glaciation, according to the report. According to the report, what it calls a new ice age was on its way until about 1960, when human-caused climate warming reversed it.
Nicolás Young, a geologist at Columbia University's Lamont-Doherty Earth Observatory and the study's lead author, said the remnant is the last piece of one of the Laurentide's domes. "Barnes is the last remaining piece of one of the domes of the Laurentide Ice Sheet," Young said, according to Ars Technica. The report said the reason Barnes can testify about its own history comes down to the temperature at its base.