Wednesday, November 08, 2023

Since 1978, North Greenland ice shelves have lost 35% of volume, study reveals


This photograph, taken by the Oceans Melting Greenland (OMG) field campaign team aboard NASA's G-III aircraft on March 26, 2016, shows Greenland's massive ice sheet from 40,000 feet. A new study published Tuesday reveals North Greenland's ice shelves have lost more than a third of their volume in the last half-century due to rising temperatures.
Photo courtesy of NASA | License Photo

Nov. 7 (UPI) -- Ice shelves in North Greenland have lost more than a third of their volume in the last half-century, with three of the shelves collapsing completely, according to researchers who warn Greenland holds enough ice to raise sea level by nearly seven feet.

The study, published Tuesday in Nature Communications, used satellite images and climate modeling to determine that North Greenland's ice shelves "have lost more than 35% of their total volume" since 1978, due to rising ocean temperatures.

"The observed increase in melting coincides with a distinct rise in ocean potential temperature, suggesting a strong oceanic control on ice shelves changes," researchers said in the study. "We are able to identify a widespread ongoing phase of weakening for the last remaining ice shelves of this sector."

Between 2006 and 2018, Greenland's ice sheet was the second-largest contributor to sea level rise, at more than 17%, according to scientists who say the discharge from ice shelves "could have dramatic consequences in terms of sea level rise."

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Accelerating pace of ice sheet melt a significant contributor to sea level rise

One of Greenland's ice shelves, called Steenbsy, dropped to just 34% of its previous volume between 2000 and 2013.

Ice shelves are more vulnerable to melting, than glaciers or ice sheets, because they float on the ocean which absorbs 90% of the planet's heat.

"We see that the ice shelves are getting weaker and weaker and weaker," said Grenoble Alpes University glaciologist Romain Millan, lead author of the paper. "We have observed that in response to this increased melting, the glaciers are retreating, and they are already discharging more ice into the ocean."



According to NASA, the summer of 2023 was Earth's hottest season ever recorded, as ocean temperatures around Florida soared above 100 degrees Fahrenheit. In August, the Mediterranean hit a record-breaking 84 degrees, according to Jordan's government.

Rising ocean temperatures throughout the world are impacting basal melt, which thins the ice from the bottom.

"These results suggest that, under future projections of ocean thermal forcing, basal melting rates will continue to rise or remain at a high level, which may have dramatic consequences for the stability of Greenlandic glaciers," researchers said.

EU: Global temperature anomalies set 2023 on track to be warmest on record

Global "surface air temperature anomalies" produced the warmest October on record with the result that 2023 is on track to be Earth's warmest ever year, the European Union's climate change service said Wednesday. 
File Photo by John Angelillo/UPI | License Photo

Nov. 8 (UPI) -- Global "surface air temperature anomalies" produced the warmest October on record with the result that 2023 is on track to be Earth's warmest ever year, the European Union's climate change service said Wednesday.

With an average temperature of 15.3 degrees Celsius, almost one degree above the 1991-2020 average and 0.4 degrees Celsius above the previous warmest October in 2019, October 2023 was the warmest since records began in 1850, The Copernicus Climate Change Service said in a news release.

The October temperature anomaly was second only to September and 1.7 degrees Celsius warmer than the average October in the benchmark pre-industrial era, determined by Copernicus as 1850-1900.

Copernicus said "exceptional anomalies" in the first 10 months of the year pushed Earth's mean temperature substantially above the pre-industrial average and 0.1 degrees Celsius higher than the warmest year on record in 2016.

Copernicus' climate Deputy Director Samantha Burgess said she was virtually certain 2023 would be the warmest year on record and that the temperatures were a wake-up call for policymakers heading to the United Nations Conference of the Parties climate summit in the United Arab Emirates in three weeks.

"October 2023 has seen exceptional temperature anomalies, following on from four months of global temperature records being obliterated. We can say with near certainty that 2023 will be the warmest year on record, and is currently 1.43 degrees Celsius above the preindustrial average," said Burgess.

"The sense of urgency for ambitious climate action going into COP28 has never been higher".

The average sea surface temperature for October was also the highest on record at 20.79 degrees Celsius with air surface and sea temperatures being driven up as El Nino conditions develop in the equatorial Pacific, although anomalies remained lower than those during record El Nino years of 1997 and 2015.

September was the warmest in recorded history as average surface air temperatures reached an unprecedented 16.4 degrees Celsius triggering an increase in extreme weather events.

Global temperatures for the month eclipsed the previous heat record set in September 2020.

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