Earth Wobbles

10 Apr 2016

At ... and at ... which in The Independent newspaper becomes a headline about global warming responsible for causing the spin axis of the earth to wobble (and no wonder that newspaper is not a viable business any longer and is ceasing a print edition).

The idea that global warming, or climate change in legal speak (as warming can easily be shown to be virtually non existent), causes the Earth to wobble, appears to be a nodding hat tip towards the consensus view that CAGW is real (when in reality it is just heavily funded) which means serious researchers have to include a global warming element in order to smooth the transition from research paper to publication. Basically, the authors are looking at how water accumulation and retreat may have affected the Earth, with a particular point of interest in how the vanishing ice sheet at the end of the Ice Age might have affected the rotation. It is the wobble in the spin axis that interests them and it is logical to explore the possibility that the removal of a large body of ice might have caused movement. It is an intriguing idea from a Catastrophist point of view and the full article may have some interesting things to say. As far as the news blurb is concerned it concentrates on global warming and drought as a factor - but then this is what funding is all about. You keep the big bucks people sweet.

The Earth's spin axis, they say, has moved in the direction of the British Isles since around AD2000 - moving at 7 inches a year (using the GRACE satellite data). They go on to point out that Earth's mantle is still readjusting to the shrinkage of the ice sheet over 10,000 years ago - which is a mainstream assumption. As space satellites, and the GRACE Mission in particular, are fairly recent avenues of research, I wonder how they might base such an opinion on the rate of wobble over  thousands of years on just a few years of data - but that is by the by as this is the sort of thing that seems to have an unfettered role in PR news reports. The idea of the hat tip is to point out, we might suppose, that a melting Greenland and Antarctic ice sheet might cause the Earth to wobble even more than it does nowadays.

However, the findings are nevertheless quite interesting as they say that the wobble has increased in recent years as a result of shrinkage of the Caspian and Aral Seas and semi arid conditions in central Asia. In other words, rainfall has reduced per a post from last year on the Caspian and movements in the rainfall belt from China to central Asia, and this can be seen to have a bearing on the wobble (if average water has declined). We might add to that the rainfall belt has moved elsewhere - in this instance further north (as the Earth has warmed coming out of the Little Ice Age of the 17th century) so we have a situation that the wobble is said to be affected by less rain in lower altitudes when at the same we have more rain, and therefore water in general, at higher latitudes. The authors then say drought across the central Asian belt seems to have had a bigger effect on the spin axis than the melting of the ice sheets at the end of the Ice Age. They rationalise this by saying that the spin axis is sensitive to change occurring around 45 degrees latitude (both N and S). Every 6 to 14 years the spin axis wobble causes a shift of 20 to 60 inches on the east and west of its direction of drift. Changes to polar ice had not discernible relationship to the wobble - possibly because the Greenland and Antarctic ice sheets have not been shrinking as alleged (just the West Antarctica peninsular). It seems the Earth can adjust its orientation as a result of the amount of water it holds at any particular time, so what would happen if something caused the poles to move and melted lots of ice?

One commenter points out the authors ignore continental drift playing a role in the wobble. Why does it have to be water. I suppose the answer to that is that water has cycles as a result of global temperatures, as seen in the next story about Easter Island. Rain belts shift - back and forwards. This can clearly be seen from a historical perspective in central Asia as the Caspian and Aral Seas grow and decline throughout recent Holocene history.