As temperatures in the Arctic rise, Greenland is undergoing its most major melting episode of the year. On Tuesday alone, the quantity of ice that melted was enough to cover the whole state of Florida in two inches of water. It's the third time severe melting has occurred in the last decade, with melting extending further inland than over the whole satellite era.
According to the Denmark Meteorological Institute, Greenland lost more than 8.5 billion tonnes of surface mass on Tuesday, and 18.4 billion tonnes since Sunday. While this week's overall ice loss isn't as significant as a similar occurrence in 2019 — a record melt year — the melting area of the ice sheet is.
"It's a substantial melt," Ted Scambos, a senior research scientist at the University of Colorado's National Snow and Ice Data Center, told a well-known news organization. "Most of the eastern half of Greenland, from the northern point to the southern tip, was mostly melted on July 27th, which is rare."
As the world warms due to human-caused climate change, ice loss has accelerated. According to a research published in the journal Cryosphere, Earth has lost an astounding 28 trillion tonnes of ice since the mid-1990s, much of it from the Arctic, including the Greenland ice sheet.
"We've already observed surface melting in Greenland become both more severe and more irregular in the last decade," said Thomas Slater, a glaciologist at the University of Leeds and one of the report's co-authors. "As the atmosphere over Greenland warms, severe melting episodes like yesterday's will become more common."
Although the present ice melting in Greenland isn't unprecedented, the scale with which it occurs is a clear indication of how climate change is causing more melt episodes. "Overall, we're finding that Greenland melts more often," said Scambos, who also writes the Greenland reports for the National Snow and Ice Data Center. "Temperatures over freezing at Greenland's peak have been exceedingly unusual in past decades or millennia."
Greenland released 532 billion tonnes of ice into the sea in 2019. An unusually warm spring and a July heatwave caused nearly the whole ice sheet's surface to melt that year. As a result, the global sea level rose by 1.5 millimeters on a permanent basis.
Slater said coastal towns throughout the world are vulnerable to storm-surge flooding as Greenland's surface continues to melt, especially when intense weather combines with high tides. Greenland melting is anticipated to boost global sea level by 2 to 10 millimeters by the end of the century, according to him.
When the air temperature is warm, massive ice sheets can melt quickly. Warmer ocean water, on the other hand, is undermining the ice sheet's borders. The rising atmosphere thaws the fresh white ice on the surface, which reflects the sun's energy back into space, while people emit heat-trapping greenhouse gases. This reveals the darker ice beneath, which absorbs sun radiation and melts faster.
Warmer coastal water also melts the ice sheet at the margins, causing large icebergs to break off, contributing to sea-level rise.
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