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The Ice Age Driver

Text: The Ice Age Driver

from Peter Ravenscroft, 18.06.09

                   
Geologists have been puzzled for at least 200 years, about what drives the ice ages and the warm periods between them.

Er...eeka !

Here, perhaps, and perhaps first up on ABC Pool, is the answer. Geomagnetism, from deep under your left boot.

The composite graph shows a very clear link - if you are used to the imperfections of geological data - between temperatures, from two quite different sources and the strength of the earth's internal magnetic field, over the past half million years.

The hard yards were done by folk at sea on rolling research vessels, drilling ice cores in the sub zeros, freezing in labs and tapping on other plastic keys. Well done all, superb effort. This lot simply summarises all that work in one image.

The temperatures were calculated quite separately from oxygen isotope ratios in marine sediments and from the Dome C ice core from Antarctica. The magnetic field strength of the planet, (the VADM or vertical axial dipole moment, to be formal), was calculated from the remnant magnetism in iron-rich grains from  many overlapping marine sedimentary sequences.
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The fits are not perfect, but one would be concerned if they were. Each of the three records, the stacked marine sediments one used for temperature proxies, the one from quite other marine sediments that was used separately for gauging the past magnetic field intensity of the planet, and the deep ice core record from Dome C in Antarctica, are subject to gaps and repeats, from both geological faulting and from unavoidable interpretive error. Continental glaciers are subject to a lot of low-angle, almost flat, faulting, on a huge scale. A normal fault will remove part of the record without trace, and a reverse fault will double it. See Google if puzzled, it will explain.

But, the fits are good enough to be able to say that either global temperatures and the global magnetic field intensity are in step for some external reason or, and I think this is more likely, that deep geomagnetic field shifts are driving the temperature changes, that is, they are driving climate change on this half million-year time-scale.

Those shifts are believed to derive from the core-mantle boundary, some 2,880 kilometres down, on average.Too deep for Holdens, as said before. You cannot change the magnetic field down at the top of the earth's core with a whiff of a trace atmospheric gas. Someone go polish the two Pennys? 

The climate modellers, the good folk from the computer gaming clubs of the world, can bang the flippers on their pin ball machines till they are blue in the face. But they will not hit the jackpot, just yet. And maybe never. But definitely not until they at least build in an extra-big flipper, for the geomagnetic shifts and reversals.

As the maps posted on Pool earlier show, the geomagnetic field shifts are also driving or are co-linked to, the largest temperature changes on the planet in the past fifty years. And carbon dioxide emissions cannot, for clear-cut geographical reasons, be driving climate change.

 I think it is hence now fair to say that the anthropogenic greenhouse warming model of climate change of the IPCC, of governments all over including Australia and of carbonists such as Al Gore, Ross Garnaut, Tim Flannery, etc,, etc., is dead in the water.

Have fun folks, it is no longer illegal. The climate is changing anyway, as it always has, and this interglacial peak we are living in, though very unstable as they all are, is probably perfectly normal, see my previous posts on ABC Pool. So our carbon emissions, though they must be trimmed anyway, are quite irrelevant to climate change (though our mad land-clearing is probably not). I am not suggesting you instantly fly in a huge ally can to some faraway beach or environment conference on tree loss, just that it's now OK to drive down to the nearest creek to launch your own canoe, or similar. Plant a mango or a bunya or something when you do, OK?

See here for more, if still not convinced. And if not, good for you, this lot needs a lot of thought yet.

Keep chewing the dog biscuits,

Hooroo,

Peter.

The cause of climate change? The answer lies Downunder.
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