Climate change and the moving north pole: science and fairy tales

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“Did you hear that climate change is even affecting the position of the north pole? Is that true?”, I was asked yesterday. And today, I found in my twitter feed:

The movie clip is pretty impressive. And the graphic in the article indicated even more:

4_8_16_Brian_PolarMotionShift_720_360_s_c1_c_c

Before 2000, Earth’s spin axis was drifting toward Canada (left globe). Climate change-driven ice loss in Greenland, Antarctica and elsewhere is pulling the direction of drift eastward.
Credit: NASA Jet Propulsion Laboratory

 

My father was professor in geodesy, and some topics, like earth rotation, earth magnetism, plate tectonics were among those topics that I found fascinating – and  I still love them. The north pole moves anywhay, so what’s happening?

How big can this impact possibly be?

Short answer: Very, very small. Yes, we already have and we will have more climate change induced problems. But the drift of the north pole is none of them.

Explanation:

Below, we see in graphic A [1] that the north pole is moving in the direction south-east (towards London) for the years 2003-2015, with a good correspondence between the observed and the calculated values; graphic B allows us to make an estimate of the magnitude of the movement.

 

Grafik

A rough estimate tells us that the change between 2003 to 2015 is 40 milliarcseconds (MAS). This corresponds to a change  in the rotation axis of 0,00001 degrees [2], or a movement of around 10 cm[3]. Some further comments: It is not new that the earts always wobbles a bit, the rotation axis is not stable; the north pole also moves a bit, a couple of centimeters a year. What is new is that the north pole has now a new average moving direction. And, btw, this has nothing to do with the meagnetic north pole.

Graphic A: Reconstruction was done using different models based on:  AOM: (nontidal) atmospheric and oceanic mass;  AIS, GIS and GICs: different areas that describe and combine the cryosphere;
TWS: area of the continental hydrosphere.

[1] Surendra Adhikari and Erik R. Ivins, Climate-driven polar motion: 2003–2015, Climatology, 2016  

[2] http://www.convertunits.com/from/milliarcsecond/to/degree

[3] reader’s comment on the article from Climate Central.

 

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