Climate scientists are sounding the alarm after an unprecedented heatwave hit Antarctica this month and delivered temperatures 20°C higher than normal.

According to a Friday report in The Guardian, temperatures at Antarctica's Trinity Peninsula this month hit peaks of over 15°C, even though it is the start of winter when ice typically expands on the continent. The prior record June temperature at the peninsula, 13.3°C, was set in 1998.

After weeks of above-average temperatures, scientists noticed that an area of sea ice that typically forms in the region—one roughly the size of France—was missing.

"It’s depressing,” Will Hobbs, an Antarctic sea ice expert at the University of Tasmania, told The Guardian. "It is remarkable that we are in June and there is no sea ice there."

Hobbs also predicted that the loss of sea ice is likely permanent at this point given the trajectory of global temperature changes.

Peter Fretwell, a scientist at the British Antarctic Survey, explained to the newspaper that the loss of sea ice poses a serious threat to penguin populations.

"Sea ice is forming too late and breaking up too early," Fretwell explained. "It leads to reduced breeding success and longer trips to moulting grounds."

In a separate interview with The Guardian last week, Raúl Cordero, a climate professor at the University of Groningen, expressed astonishment at the record-breaking Antarctic heat.

“This is absolutely crazy,” Cordero said. "That is a huge anomaly.”

Luis Muñoz, a Chilean glaciologist, told the newspaper he was shocked to step outside at King George's Island, located just north of Trinity Peninsula, and seeing the ground uncovered by snow.

"The temperatures here went very high so everything outside melted,” Muñoz explained. “Usually there is 20 centimeters of snow and a lot of ice on the ground at this time.”

Taking stock of the bigger picture, the newspaper reported that scientists are now fearful that some of the biggest glaciers in the region of the peninsula have now "past a tipping point" that could "push up global sea levels by four meters."

Such a rise in global sea levels would be unprecedented. Scientists estimate that global sea levels have risen by between 21 and 24 centimeters since 1880.