Scientists announced Wednesday that 2016 was the hottest year on record for the Earth. 2016 beat the record set the year before, which itself beat the record set in 2014. In other words, the Earth has met a troubling milestone, breaking temperature records for three years in a row.

As Justin Gillis reports for The New York Times, these record temperatures were especially extreme in the Arctic, where temperatures ran 20-30 degrees Fahrenheit above normal.

“A single warm year is something of a curiosity,” said Deke Arndt, chief of global climate monitoring for the National Oceanic and Atmospheric Administration (NOAA). “It’s really the trend, and the fact that we’re punching at the ceiling every year now, that is the real indicator that we’re undergoing big changes.”