For the first time on record, rain fell at the summit of Greenland ice sheet.
Last weekend, temperatures at Greenland’s highest point rose above freezing for the first time this decade. That fueled an extreme rain event that dumped 7 billion tons of water on the ice sheet.
The summit usually only sees snow.
According to the National Snow and Ice Data Center, it was the heaviest rainfall since record-keeping began in 1950.
A senior research scientist at the data center said it's proof that Greenland is warming rapidly.
The National Science Foundation’s Summit Station is located at the top of the Greenland ice sheet. Scientists there observe arctic weather and extreme changes in the ice.
The station has been staffed year-round since 1989.