Shocking before-and-after photos reveal how much the Greenland ice sheet melted during the “hottest month ever recorded on Earth.”
Taken on June 14, the first image ever taken by a US satellite shows the Greenland ice sheet just before summer temperatures settled.
Meanwhile, the second image from July 24 shows the same region with substantially less snow cover and patches of “dirty” ice where impurities have been exposed.
According to scientists, snow falls on the Greenland ice sheet each winter and acts as a protective layer for the ice below during the summer.
But experts say higher summer temperatures are reducing the amount of snow and making ice more prone to melting, contributing to sea level rise.
The new images, taken by US Landsat satellites, show the amount of snow covering the Greenland ice sheet.
Scientists have already said July is “virtually certain” to be the world’s hottest month on record, while UN Secretary-General António Guterres warned last month that “the era of global boiling has arrived”. .
The images were taken by Landsat 8 and Landsat 9, two satellites of the US Earth Observation Program, a collaboration between NASA and the United States Geological Survey (USGS).
“More than halfway through the 2023 melt season, Greenland has seen a substantial transformation of its snow cover,” NASA said in a statement. blog post.
‘The changes are a result of the increasing warmth of the summer weather that gripped the region in late June.
“That’s when warm southwesterly winds and clear skies significantly increased the amount of ice sheet melt, especially toward the south of the island.”
Ice sheets are sheets of ice that cover a vast expanse of land—more than 20,000 square miles (50,000 square kilometers).
The Greenland Ice Sheet is a vast body of ice that covers 656,000 square miles, which is about 80 percent of Greenland’s area.
It is one of two ice sheets in the world, along with the much larger Antarctic Ice Sheet (5.4 million square miles).
Dr Bethan Davies, a senior lecturer in physical geography at Newcastle University, stressed that recent Landsat images show the amount of snow, not ice, in the region.
The Greenland Ice Sheet (pictured) covers about 656,000 square miles, about 80% of Greenland’s area.
Every winter, it snows on Greenland, and this snow usually remains throughout the summer and acts as a sort of protective shell for the ice mass below.
But warmer summers in recent years have meant that this snow has been melting at lower and lower altitudes, leaving more ice exposed.
When ice is exposed, it can melt and potentially contribute to sea level rise.
“This year, in 2023, the snow melt on the ice sheet surface is higher than the 1981-2010 average,” Dr Davies told MailOnline.
“The more years we have major or excessive melting, the more of the Greenland ice sheet will be lost to the ocean.
“Greenland’s mass loss is increasing, driven by these hot summers with high surface melt.
“This process will increase the contribution of the Greenland ice sheet to sea level rise and reduce the area of the ice sheet.”
The second image, from July 24, shows that the Greenland ice sheet also looks remarkably different: darker and evenly uniform.
It appears almost “dirty” due to the presence of particles, such as black carbon or dust, that have accumulated and are left behind when the snow and ice melt.
In the image, the Frederikshåb Glacier, captured on July 24. This lobe-shaped glacier flows down from the Greenland ice sheet.
This in itself is also a problem, as darker surfaces absorb more solar energy, further accelerating ice melt in the summer months.
“The snow is brilliant white, while the ice from the glaciers is a duller, bluish-grey,” Dr Davies told MailOnline.
‘In the NASA image there is a lot of dust on the ice and this makes it darker.
“This means that snow reflects more solar energy, while ice absorbs more solar energy, resulting in more melting.”
A third image, taken on July 8, shows the scattered presence of deep blue ‘melt ponds’ – pools of water that form where snow melts and collects in low places.
July 8, 2023: Deep blue ‘melt ponds’ dot the ice sheet. These melt ponds form where snow melts and accumulates in low spots.
In the July 24 image, only a few melt ponds are visible, likely because water had already escaped from the ice sheet or funneled through the ice.
Melting from the Greenland ice sheet has been above average for much of the season, according to the National Snow and Ice Data Center.
Over several days in June and July, ice melt was detected across 302,000 square miles of the Greenland ice sheet, up to half of its surface.
Scientists warned earlier this year that the Greenland ice sheet is hotter than ever and will cause global sea levels to rise 20 inches by 2100 if it continues to warm at the same rate.
