Loss of a rare lake reveals how warming has hit the Canadian Arctic’s ‘planetary fridge’

When an ice shelf blocks a polar fjord, it sparks the creation of an ecosystem like no other: the epishelf lake. Meltwater pools up behind the ice shelf, floating above the denser seawater, with both freshwater and marine species found in distinct layers within the same water column. But Canada’s last known epishelf lake, at Milne Fjord on Ellesmere Island in Nunavut, is gone. The lake drained out to sea after the Milne Ice Shelf calved in 2020, and it won’t return, according to a recent study published in Scientific Reports. Ellesmere Island lies within the Last Ice Area, a region of the Arctic that scientists have long thought would retain its sea ice longer than elsewhere as the planet warms. The changes at Milne Fjord are a signal of accelerating climate change, with implications for the entire planet. “What happens in the Arctic doesn’t stay in the Arctic,” study co-author Derek Mueller, a professor at Carleton University in Ontario, told Mongabay in a video call. Meltwater lakes form in the depressions of Milne Ice Shelf every summer. Image by Jérémie Bonneau. In the past, ice shelves dammed Ellesmere’s many fjords, with an estimated 10 to 17 epishelf lakes perched along its north coast as recently as the 20th century. But over the past several decades, dramatic warming, driven by the burning of fossil fuels, has transformed this region. One by one, giant ice shelves have split and calved, allowing the epishelf lakes to drain away. When the massive 65-meter-deep…This article was originally published on Mongabay