HIGHLIGHTS
• About 60 per cent cover on Greenland's ice sheet has seen surface melting
• July 31 was the biggest melt day since at least 2012
• The ice melting could raise sea levels by 0.02 inches in a month's time
When one thinks of Greenland, images of an icebound, harsh and forbidding landscape probably come to mind, not a landscape of ice pocked with melt ponds and streams transformed into raging rivers. And almost certainly not one that features wildfires.
Yet the latter description is exactly what Greenland looks like today, according to imagery shared on social media, scientists on the ground and data from satellites.
An extraordinary melt event that began earlier this week continues on Thursday on the Greenland ice sheet, and there are signs that about 60% of the expansive ice cover has seen detectable surface melting, including at higher elevations that only rarely see temperatures climb above freezing.
July 31 was the biggest melt day since at least 2012, with about 60% of the ice sheet seeing at least 1 millimeter of melt at the surface, and more than 10 billion tons of ice lost to the ocean from surface melt, according to data from the Polar Portal, a website run by Danish polar research institutions, and the National Snow and Ice Data Center. Thursday could be another significant melt day, before temperatures drop to more seasonable levels.
According to Ruth Mottram, a climate researcher with the Danish Meteorological Institute, the ice sheet sent 197 billion tons of water pouring into the Atlantic Ocean during July.
This is enough to raise sea levels by 0.1 millimeter, or 0.02 inches, in a one-month time frame, said Martin Stendel, a researcher with the institute.
This might seem inconsequential, but every increment of sea-level rise provides a higher launchpad for storms to more easily flood coastal infrastructure, such as New York's subway system, parts of which flooded during Hurricane Sandy in 2012. Think of a basketball game being played on a court whose floor is gradually rising, making it easier for even shorter players to dunk the ball.
As a result of both surface melting and a lack of snow on the ice sheet this summer, "this is the year Greenland is contributing most to sea-level rise," said Marco Tedesco, a climate scientist at Columbia University.
Thanks to an expansive area of high pressure enveloping all of Greenland - the same weather system that brought extreme heat to Europe last week - temperatures in Greenland have been running well above average this week.
At Summit Station, which at 10,551 feet is located at the highest point in Greenland and rarely sees temperatures above freezing, the thermometer exceeded this mark for about eight hours Tuesday, according to Christopher Shuman, a glaciologist at the University of Maryland-Baltimore County and NASA Goddard Space Flight Center.
The ongoing melt event is being compared to a record extreme heat and melt episode that occurred in Greenland in 2012. While the extent of surface melt during that event may have exceeded this one so far, Shuman found that Summit Station experienced warmth that was greater "in both magnitude and duration" during the current event. During the 2012 extreme event, however, 97 percent of the ice surface experienced melting.