Extent of surface melt over Greenlands ice sheet on July 8 (left) and July 12 (right). Measurements from three satellites showed that in just a few days, the melting had dramatically accelerated and an estimated 97 percent of the ice sheet surface had thawed by July 12.Nicolo E. DiGirolamo, SSAI/NASA GSFC, and Jesse Allen, NASA Earth Observatory
NASA’s claim that Greenland is experiencing “unprecedented” melting is nothing but a bunch of hot air, according to scientists who say the country's ice sheets melt with some regularity.
A heat dome over the icy country melted a whopping 97 percent of Greenland’s ice sheet in mid-July, NASA said, calling it yet more evidence of the effect man is having on the planet.
But the unusual-seeming event had nothing to do with hot air, according to glaciologists. It was actually to be expected.
"Ice cores from Summit station [Greenland’s coldest and highest] show that melting events of this type occur about once every 150 years on average. With the last one happening in 1889, this event is right on time," said Lora Koenig, a Goddard glaciologist and a member of the research team analyzing the satellite data.
But rather than a regular 150-year planetary cycle, the new NASA report calls the melt “unprecedented,” the result of a recent strong ridge of warm air, or a heat dome, over Greenland -- one of a series that has dominated Greenland's weather since the end of May.
'NASA should start distributing dictionaries to the authors of its press releases.'
- Patrick J. Michaels, a climatologist
"Each successive ridge has been stronger than the previous one," said Thomas Mote, a climatologist at the University of Georgia. This latest heat dome started to move over Greenland on July 8, and then parked itself over the ice sheet about three days later. By July 16, it had begun to dissipate, along with the ice, NASA said.
Climate skeptics said the NASA report itself was the only “unprecedented” item.
“NASA should start distributing dictionaries to the authors of its press releases,” joked Patrick J. Michaels, a climatologist and the author of the World Climate Report blog.
“It’s somewhat like the rush to blame severe weather and drought on global warming,” Anthony Watts, a noted climate skeptic and the author of the Watts Up With That blog, told FoxNews.com. “Yet when you look into the past, you find precedence for what is being described today as unprecedented.”
It's the latest hot water for the National Aeronautics and Space Administration, which critics say has shifted focus and priorities from space and aeronautics to the earth we live on -- and the planet's changing climate.
NASA chief cryospheric scientist H. Jay Zwally told FoxNews.com that the melting has been increasing as the temperatures in Greenland have been increasing.
“Climate in the Arctic has been warming about three to four times more than the global average, and Greenland surface temperatures (observed by satellite and surface instruments) have been increasing about 2 degrees Celsius per decade during about the last 20 years,” he said.
Zwally would be in a position to know: He was lead scientist for the ICESat project, which ran from 2003 to 2010, and used satellites to measure Antarctic and Greenland ice sheets.
“This is the most extensive area of surface melting during last 40 years of satellite observations,” he said.
It may be in line with the 150-year cycles of melting, however. Mary Albert, executive director of the NSF Ice Core Drilling office, and Kaitlin Keegan, an engineering PhD student and a fellow in Dartmouth’s polar environmental change program, are working on a paper on the Greenland ice sheet melt, a school spokeswoman told FoxNews.com.
Neither was available to describe the exact findings, but in a blog posting detailing her work, Keegan noted that several cores dating back millennia have also reflected the 150-year cycle.
“In Greenland there have been many deep ice-core drilling projects which drilled ice to the bedrock,” she wrote. “In the past 10,000 years (the Holocene), there is on average a melt layer every 150 years.”
NASA ice scientist Tom Wagner told the Associated Press researchers don't know precisely how much of Greenland's ice had melted in this latest event, but it seems to be freezing again.
“The belief that almost any aberration in weather and climate today can be attributed to global warming is pure folly,” Watts told FoxNews.com.