Is Greenland Rapidly Melting Away?

Dec 30, 2015



ScienceNordic just published an article titled, “Greenland has lost 9,000 billion tons of ice in a century.” Actually, the headline has a typo in it. It should say trillion, not billion. My article applies trillion as the original authors of the study intended.

Science Nordic

That sounds far more dramatic than saying Greenland still has 99.7% of the ice it had in 1900, which is actually saying the same thing when you take into consideration the total amount of ice that makes up Greenland’s ice sheet.

Converting the numbers into cubic area (an ice cube if you will), Greenland lost 8,165 km3 of its estimated 2,608,165 km3 of ice that it had back in 1900.

Working the Math:

8165/2608165 = 0.003 x 100 = 0.3%
100% - 0.3% = 99.7%

We need some historical perspective to determine if this is an unprecedented amount of ice loss.

Greenland had considerably less ice than today during the Medieval Warm Period (MWP) which lasted from 800 to 1350 AD. We know this because the Vikings settled the Southern and Southwestern coastal areas with large farms during the MWP. They abandoned Greenland when the MWP ended because it grew too cold to farm and maintain trade routes. The areas they settled are still too cold to farm today. Many of the Viking farms of that era are now under the Greenland ice sheet.

Viking Routes
Routes and Settlement of the Vikings During MWP


Olafur Einarsson (1573 - 1659), who lived in the settlements not long before they were completely abandoned, wrote:

Formerly the earth produced all sorts
of fruit, plants and roots.
But now almost nothing grows....

Then the floods, the lakes and the blue waves
Brought abundant fish.
But now hardly one can be seen.
The misery increases more.
The same applies to other goods....

Frost and cold torment people
The good years are rare.
If everything should be put in a verse
Only a few take care of the miserables....

Note that he draws attention to the fact that at one time the settlement grew a bounty of produce but, at the time of his writing, the frost and cold tormented what few miserable people were left.

Thus, we have evidence to conclude that not only is today’s ice loss not significant, it’s no where near the amount of ice loss during the MWP. If we continue to warm, it would make sense that Greenland will lose a little more ice. After all, we are still coming out of the Little Ice Age which just ended around 1870 AD. We’ve entered into the Modern Warm Period.

Satellites show the warming of the past 145 years has stagnated for 18+ years. The direction of the PDO and AMO indexes, which largely regulate our multi-decadal temperature swings, suggest it may remain stagnated or get colder for another two to four decades. Thus, I wouldn’t expect Greenland’s ice loss rate to increase during that time. Nonetheless, we are still on a longer term warming trend that may continue for another 100 to 150 years if the length of past cycles of warm and cold periods hold true.

UAH Temperature History
Official UAH satellite temperature history which shows no statistically significant warming for the past 18+ years


Our current multi-centennial warming trend is superimposed on top of a multi-millennial trend that has steadily been growing colder. We should be happy to be living in our slightly warmer time. It won’t last.

Sources:

• sciencenordic.com/greenland-has-lost-9000-billion-tons-ice-century
• wattsupwiththat.com/2015/12/30/greenland-retained-99-7-of-its-ice-mass
  -in-20th-century (WUWT)
• McGovern and Perdikaris (2000)
• www2.sunysuffolk.edu/mandias/lia/vikings_during_mwp.html
• www2.sunysuffolk.edu/mandias/lia/decline_of_vikings_iceland.html
• www.sciencemag.org/content/342/6158/617
• www.drroyspencer.com/latest-global-temperatures
• Credit to David Middleton, who researched Greenland's ice mass (WUWT).


Edit: December 31, 2015 - I fixed a minor typographical error of my own. I also added additional wording to clarify that I am using the correct numbers the original study authors intended.







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