The days in Nuuk, Greenland's capital, are growing longer. Even after setting, the sun lingers below the horizon, casting a glow over the rocky coastal landscape. On sun-drenched days, when the skies are as blue as the ocean, one can admire Greenland's striking mountains. Their jagged summits contrast with the smoothness of their lower slopes, fjords shaped by the relentless force of ancient ice sheets. Here and there, splashes of fragrant brownish-green tundra punctuate the scene. Everywhere, the snow is melting, making for slushy treks through a wet and heavy snowpack.
Before landing in Greenland at the start of the melt season, I expected to see more snow. But only patches of winter snow remained. One does not need to be a scientist to observe the trends that we researchers can detect via satellites and other long-term measurements. The snowfall has been arriving later in the year, sometimes after Christmas, and has not been as persistent as it once was. After a quarter-century of losing mass, the Greenland Ice Sheet has been undergoing a rapid and radical transformation.
The US National Oceanic and Atmospheric Administration's Arctic Report Card for Greenland, which I co-authored, paints a grim picture. In 2022, Greenland marked its 25th consecutive year of ice loss, accompanied by "unprecedented late-season melt events." On Sept 3, more than a third of the ice sheet's surface -- including Summit Station, a research camp near the ice sheet's apex -- experienced melting conditions. A year before, in August 2021, Summit Station documented its first-ever recorded rainfall, although it was impossible to say exactly how much it received, owing to the absence of rain gauges at such high altitudes.
