"Glacier Shrinkage" Data Reveal Extent of Measurement Bias

Glaciers suffer record shrinkage” say the BBC on its front page, International version tonight. Cue mentions of millions of people in danger of being left almost without water; talks about canaries and coal mines; and appeals for an immediate “green” change of people, economies and the whole society.

Google News report an alleged 122 news articles about the same story:

The rate at which some of the world’s glaciers are melting has more than doubled, data from the United Nations Environment Programme [UNEP] has shown

So much for the news though. Let’s investigate the original source. And lo and behold, things are quite different from what has been reported.

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A quick search brings one to the website for the World Glacier Monitoring Service (WGMS), the Zurich-based group that is actually collecting the data for the UNEP. Top news on their home page, “The preliminary mass balance data for the year 2006 is now available!“.

Why it is out now, it’s explained in the other news: “Workshop on mass balance measurements and modelling (26-28 March 2008, Skeikampen, Norway)!

WGMS say more or less what the news is reporting:

Preliminary mass balance values for the year 2006 are now available from more than 80 glaciers worldwide. The continuous mass balance statistics below are calculated based on the 30 glaciers in 9 mountain ranges*** […]

The average mass balance of the glaciers with available long-term mass balance series around the world continues to decrease, with tentative figures indicating a further thickness reduction of 1.4 m w.e. (*) during the hydrological year 2006. This continues the trend in accelerated ice loss during the past two and a half decades and brings the total loss since 1980 at more than 10.5 m w.e.

An analysis of the published data reveals something else.

First of all one minor error (positive balances occur in 5 glaciers, not 4). Then something a tad more significative: the actual reported mean thickness reduction is 1.301m, not 1.4m. The difference is around 10cm, that is 100 times the claimed resolution of 1mm.

But the biggest revelation is actually a confirmation: of the extraordinary extent of measurement bias in all things about so-called GLOBAL warming.

(1) What is the distribution for the “30 glaciers in 9 mountain ranges” included in the WGMS analysis? 20 in Europe; 4 in North America; 6 in the rest of the world. That is: 66.7% in Europe, 13.3% in North America, 20% in the rest of the world.

(2) How many glaciers are included in the full WGMS list? 111. Of those: 60.4% in Europe, 24.3% in North America, 15.3% in the rest of the world.

(3) For how many glaciers is there data for 2005/2006? 97. Of those: 66.0% in Europe, 22.7% in North America, 11.3% in the rest of the world.

(4) How are thickness reductions distributed? Of the largest 19, 18 relate to European glaciers, and only one to a North American glacier. The first glacier from the rest of the world ranks 35 out of 97.

(5) How many glaciers show a thickness reduction larger than 10cm? 88. Of those: 69.3% in Europe, 20.5% in North America, 10.2% in the rest of the world.

(6) What is the average thickness reduction in all the glaciers for which data is available? 1.142m. In particular: 1.337m for Europe, 0.865m for North America, 0.565m for the rest of the world. Surely it must be by pure chance that the official WGMS statistics use a particular set of glaciers whose average thickness reduction is larger than the whole dataset’s.

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The pro-European (and pro-North American) bias is so blatant it doesn’t need any further qualification.

I have already shown how the IPCC itself may have unwittingly indicated that “Global Warming may be just European“. And now it may as well be the turn of the WGMS: for all we know, glaciers have been shrinking especially in the Northern Hemisphere temperate regions.

Is this sign of a “global” phenomenon? Who knows?

In truth, there is no meaning in speaking of “global warming” or of “global climate change” until the data are sufficiently “global“.

Let’s hope it will happen, one day…

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(*) w.e.” means “water equivalent“.

Mass balance is reported in meters of water equivalent. This represents the average thickness gained (positive balance) or lost (negative balance) from the glacier during that particular year.”