The Great Greenland Meltdown Con
via NOT A LOT OF PEOPLE KNOW THAThttps://notalotofpeopleknowthat.wordpress.com
By Paul Homewood
Another day, another ludicrous Greenland meltdown scare story:
From “Science”:
From a helicopter clattering over Greenland’s interior on a bright July day, the ice sheet below tells a tale of disintegration. Long, roughly parallel cracks score the surface, formed by water and pressure; impossibly blue lakes of meltwater fill depressions; and veiny networks of azure streams meander west, flowing to the edge of the ice sheet and eventually out to sea.
The scientists flying over the world’s largest thawing chunk of ice have selected a particularly auspicious summer to be studying the melt. The edges of Greenland’s 1.7-million-km2 ice sheet regularly melt in summer, even in years when the ice sheet as a whole grows because of snowfall in its higher, colder center. But in 2016, the melting started early and spread inland fast. By April, 12% of the ice sheet’s surface was melting; in an average year the melt doesn’t reach 10% until June. And just before the scientists’ journey, a violent river of meltwater, one of hundreds coursing out from the ice sheet, swept away a sensor, bolted to a bridge to measure the water’s turbidity. It was the second time in 4 years such a device had fallen victim to the liquid fury of the glaciers. "I’ve been doing these trips for years, but I’ve never seen so much water," the helicopter pilot told the researchers.
In Greenland, the great melt is on. The decline of Greenland’s ice sheet is a familiar story, but until recently, massive calving glaciers that carry ice from the interior and crumble into the sea got most of the attention. Between 2000 and 2008, such "dynamic" changes accounted for about as much mass loss as surface melting and shifts in snowfall. But the balance tipped dramatically between 2011 and 2014, when satellite data and modeling suggested that 70% of the annual 269 billion tons of snow and ice shed by Greenland was lost through surface melt, not calving. The accelerating surface melt has doubled Greenland’s contribution to global sea level rise since 1992–2011, to 0.74 mm per year. "Nobody expected the ice sheet to lose so much mass so quickly," says geophysicist Isabella Velicogna of the University of California, Irvine. "Things are happening a lot faster than we expected."
They begin with the early melt last April, but forgot to say that was due to a warm and wet weather front from the Atlantic. NSIDC explained that similar events have happened in the past, and after a few days the melt had stopped.
Over the year as a whole, the accumulated surface mass balance of the Greenland ice sheet was close to the long term average. This year, of course, it is running well above average.
Top: The total daily contribution to the surface mass balance from the entire ice sheet (blue line, Gt/day). Bottom: The accumulated surface mass balance from September 1st to now (blue line, Gt) and the season 2011-12 (red) which had very high summer melt in Greenland. For comparison, the mean curve from the period 1990-2013 is shown (dark grey). The same calendar day in each of the 24 years (in the period 1990-2013) will have its own value. These differences from year to year are illustrated by the light grey band. For each calendar day, however, the lowest and highest values of the 24 years have been left out.
Meanwhile, temperatures last year in Nuuk, close to where the study took place, were the lowest since the 1993.
Apart from the anomalously mild year of 2010, temperatures since 2000 have been similar to the 1930s and 40s.
The DMI’s SW Greenland Series, most recently updated to 2013, shows that recent summer temperatures have also been similar to the 1930s.
Last summer, the mean temperature at Nuuk was 6.9C, which according to GISS is only the 28th warmest since 1900, and well below the summers of 1931 and 1948 which reached 8.0C.
As the Science article points out, there has been some calving of glaciers, But this needs to be put into perspective.
We know from ice cores that the 19thC was the coldest period since the end of the ice age.
Other studies, such as this one from Kelly & Long, support this fact. They also say that the Greenland ice sheet and mountain glaciers reached their maximum extents since the early Holocene during the Little Ice Age.
It is little surprise then that glaciers have been gradually receding since then.
These Greenland scare stories usually have certain common denominators:
1) Helicopter photos of melt pools and running water.
2) A few years of satellite data of ice sheet mass loss.
3) A focus on a day or two of warm weather.
None of them put these into any sort of perspective, or explain that such events are perfectly common. Instead they pretend that this is all something new and deadly, simply because nobody has been around to spot it before.
They get away with it because the public are too gullible and the media too complicit.
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February 25, 2017 at 06:57AM
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